Paul J. Wang: Welcome to the monthly podcast On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, editor-in-chief with some of the key highlights from this month's issue. In our first paper, Danielle Haanschoten, Hein Wellens and Associates aim to examine survival benefit of prophylactic implantable cardioversion defibrillator (ICD) implantation in early selected high-risk patients with primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). A randomized, multicenter, controlled trial compared ICD versus conventional medical therapy in high-risk primary PCI patients based on one of the following factors: Left ventricular ejection fraction (LVF) less than 30% within four days of STEMI, primary ventricular fibrillation, Killip class 2 or greater and/or TEMI flow less than three after PCI. ICD was implanted 30 to 60 days after MI, myocardial infarction, primary endpoint was all cause mortality three years of follow-up. The trial was prematurely ended after inclusion of 266 patients, 38% of the calculated sample size. Additional survival assessments was performed in February 2019 for the primary endpoint. A total of 266 patients, 78.2% male with a mean age of 60.8 years were enrolled. 131 were randomized to the ICD arm and 135 patients to the control arm. All cause mortality was significantly lower in the ICD group, five versus 13, hazard ratio of 0.37 after three years follow-up. Appropriate ICD therapy occurred in nine patients at three years follow-up, 5 within the first eight months after implantation. After median long-term follow-up of nine years, total mortality (18% versus 38%, hazard ratio of 0.58) and cardiac mortality (hazard ratio of 0.52) was significantly lower in the ICD group. Non-cardiac death was not significantly different between the groups. LVEF increased 10% or more in the 46.5% of patients during follow-up and the extent of improvement was similar in both study groups. The authors concluded that in this prematurely terminated and thus underpowered randomized trial early prophylactic ICD implantation demonstrated lower total and cardiac mortality in high-risk STEMI patients treated with primary PCI.   In our next paper Felipe Bisbal, Eva Benito and Associates aim to test the efficacy of ablating, cardiac magnetic resonance, CMR detected atrial fibrosis plus pulmonary vein isolation (PVI). This was an open label, parallel group, randomized controlled trial. Patients with symptomatic drug refractory AF paroxysmal or persistent undergoing first or repeat ablation were randomized one-to-one basis to receive PVI plus CMR-guided fibrosis ablation, the CMR group or PVI alone, the PVI alone group. The primary endpoint was a rate of recurrence greater than 30 seconds at 12 months of follow-up using a 12-lead ECG and Holter monitoring at 3, 6 and 12 months. The analysis was conducted by intention to treat. In total 155 patients, 71% male, age 59, CHADS2-VASc 1.3, 54% paroxysmal AF were allocated to the PVI group alone (n=76) or CMR group(n=79). First ablation was performed in 80% and 71% in the PVI alone and CMR groups respectively. The mean atrial fibrosis burden was 12%, only approximately 50% of patients had fibrosis outside the pulmonary vein area. 100% and 99% of patients received the assigned intervention in the PVI alone and CMR group. Primary outcome was achieved in 21 patients (27.6%) in the PVI alone group and 22 patients (27.8%) in the CMR group (Odds ratio 0.01, P=0.976). There was no differences in the rate of adverse events, three in the CMR group and two in the PVI alone group. The authors concluded that a pragmatic ablation approach targeting CMR detected atrial fibrosis plus PVI was not more effective than PVI alone in an unselected population undergoing AF ablation with low fibrosis burden.   In the next paper, Vivek Reddy and Associates tested a novel neuromodulation therapy of stimulation of epicardial cardiac nerves passing along the posterior surface of the right pulmonary artery. 15 subjects admitted for defibrillator implantation (ejection fraction≤35%) on standard heart failure medications were enrolled. Through femoral arterial access, high fidelity pressure catheters were placed in the left ventricle and aortic root. After electro anatomic rendering of the pulmonary artery and branches, either a circular or basket electrophysiology catheter was placed in the right pulmonary artery to allow electrical intravascular stimulation at 20 hertz, 4 ms pulse width, and less than or equal to 20 milliamperes. Changes in the maximum positive dP/dt, the dP/dtMax indicated change in ventricular contractility. Of 15 enrolled patients, five were not studied due to equipment failure or abnormal pulmonary artery anatomy. In the remaining patients dP/dtMax increased significantly by 22.6%. There was also a significant increase in maximum negative dP/dt, dP/dtMin, mean arterial pressure, systolic pressure, diastolic pressure, and left ventricular systolic pressure. There was no significant change in heart rate or left ventricular diastolic pressure. In this first-in-human study, the authors demonstrated that in humans with stable heart failure, left ventricular contractility could be accentuated without an increase in heart rate or left ventricular filling pressures.   In our next paper, Jorge Romero, Luigi Di Biase, and Associates, in their study investigated the incremental benefit of left atrial appendage electrical isolation (LAAEI) in patients undergoing catheter ablation for nonparoxysmal atrial fibrillation (AF). Propensity score-matched analysis was performed using a prospective registry database from 2010 to 2014. All patients in the LAAEI group were matched based on baseline characteristics, echocardiographic parameters, and procedural ablation techniques. Authors identified 1842 patients who underwent catheter ablation for nonparoxysmal atrial fibrillation. Propensity score matching yielded 1092 patients, 546 with LAAEI, and 546 without LAAEI. At five years follow-up, overall freedom from all arrhythmia recurrence, off-antiarrhythmic drugs, in patients who underwent LAAEI was 68.9% versus 50.2% in those who underwent standard ablation (p

Your monthly summary and report on new research

Circulation: Arrhythmia and Electrophysiology November 2020 Issue

Paul J. Wang: Welcome to the monthly podcast, On the Beat for Circulation, Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, editor-in-chief with some of the key highlights from this month's issue. In our first paper, Bruce Wilkoff and associates evaluated antibacterial envelope cost effectiveness compared to standard of care infection prevention strategies in the US healthcare system. Decision tree model was used to compare costs and outcomes of the antimicrobial envelope used adjunctive to standard of care infection prevention versus standard of care alone over a lifelong time horizon. The analysis was performed from an integrated payer provider network perspective. Infection rates, antimicrobial envelope effectiveness, infection treatment costs and patterns, infection related mortality and utility estimates were obtained from the WRAP-IT study. Life expectancy and long-term costs associated with device replacement, follow-up, and healthcare utilization were sourced from the literature. Costs and quality life adjusted years were discounted at 3%. An upper willingness-to-pay threshold of $100,000 per quality adjusted life year was used to determine cost-effectiveness in alignment with the American College of Cardiology and American Heart Association practice guidelines and as supported by the World Health Organization and contemporary literature. The base case incremental cost-effectiveness ratio (ICER) of the antibacterial envelope compared with standard-of-care was $112,603 per quality-adjusted life year. The ICER remained lower than the threshold in 74% of iterations in the probabilistic sensitivity analysis and was most sensitive to the following model inputs: infection-related mortality, life expectancy, and infection cost. The authors concluded that the absorbable antibacterial envelope was associated with a cost-effectiveness ratio below contemporary benchmarks in the WRAP-IT patient population, suggesting that the envelope provides value for the US healthcare system by reducing the incidence of CIED infection. In our next paper, Peter Loh and associates in this study aim to investigate the feasibility and safety of single pulse irreversible electroporation (IRE) pulmonary vein (PV) isolation in patients with atrial fibrillation (AF). Ten patients with symptomatic paroxysmal or persistent AF underwent single pulse IRE pulmonary vein isolation under general anesthesia. Three-dimensional reconstruction and electroanatomical voltage mapping of the left atrium and pulmonary veins were performed using a conventional circular mapping catheter. Pulmonary vein isolation was performed by delivering nonarcing, nonbarotraumatic 6 ms, 200 Joule direct current IRE applications via a custom nondeflectable 14-polar circular IRE ablation catheter with a variable hoop diameter (16–27 millimeters). A deflectable sheath was used to maneuver the ablation catheter. A minimum of 2 IRE applications with slightly different catheter positions were delivered per vein to achieve circular tissue contact, even if pulmonary vein potentials were abolished after the first application. Bidirectional pulmonary vein isolation was confirmed with the circular mapping catheter and a post ablation voltage map. After a 30-minute waiting period, adenosine testing was used to reveal dormant pulmonary vein conduction. All 40 pulmonary veins could be successfully isolated with a mean of 2.4 IRE applications per pulmonary vein. Mean delivery peak voltage and peak current were 2154 volts and 33.9 amperes. No pulmonary vein reconnections occurred during the waiting period and adenosine testing. No periprocedural complications were observed. The authors concluded that in 10 patients in this first in-human study, acute bidirectional electrical pulmonary vein isolation could be achieved safely using single pulse IRE ablation. In our next paper, Christian Sohns and associates studied the relationship between left ventricular ejection fraction (LVEF) New York Heart Association (NYHA) class on presentation and the end points of mortality and heart failure (HF) admissions in the CASTLE-AF study population. Furthermore, predictors for LVEF improvement were examined. The CASTLE-AF patients with coexisting heart failure and AF (n=363) were randomized in a multicenter prospective controlled fashion to ablation (n=179) versus pharmacological therapy (n=184). Left ventricular function in NYHA class were assessed at baseline after randomization and at each follow-up visit. In the ablation arm, a significantly higher number of patients experienced an improvement in their LVEF to greater than 35% at the end of the study (odds ratio, 2.17; P

Circulation: Arrhythmia and Electrophysiology October 2020 Issue

Paul J. Wang: Welcome to the monthly podcast, On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, Editor-in-chief, with some of the key highlights from this month's issue. In our first paper, Zak Loring and associates examined 3,139 patients undergoing atrial fibrillation (AF) ablation, between 2016 and 2018 in the Get With The Guidelines-Atrial Fibrillation Registry from 24 US centers. Patients undergoing AF ablation were predominantly male (63.9%) and Caucasian (93.2%) with a median age of 65. Hypertension was the most common comorbidity (67.6%), and persistent atrial fibrillation patients had more comorbidities than paroxysmal AF patients. Drug refractory, paroxysmal AF was most common ablation indication (class I, 53.6%) followed by drug refractory, persistent AF (class I, 41.8%). Radio-frequency, RF ablation, with contact force sensing was the most common ablation modality (70.5%) and 23.7% of patients underwent cryoballoon ablation. Pulmonary vein isolation was performed in 94.6% of de novo ablations. The most common adjunctive lesion included left atrial roof or posterior/inferior lines and cavotricuspid isthmus ablation. Complications were uncommon (5.1%) and were life-threatening in 0.7% of cases. In our next paper, Brian Howard and associates hypothesize that pulse field ablation (PFA) would reduce pulmonary vein stenosis risk and collateral injury compared to irrigated radiofrequency ablation (IRF). IRF and PFA deliveries were randomized in eight dogs with two superior pulmonary veins (PVs), ablated with using one technology and two inferior PVs ablated with the other technology. IRF energy (25-30 watts) or PFA with delivered (16 pulse trains) at each PV in a proximal and in a distal site. Contrast computed tomography (CT scans) were collected at 0, 2, 4 and 8, and 12 week, including termination time points to monitor PV cross-sectional area at each PV ablation site. Maximum average change in normalized cross-sectional area at 4 weeks was 46.1%±45.1% post IRF compared to -5.5±20.5% for PFA (P≤ to 0.001). Necropsy showed expansive PFA lesions without stenosis in the proximal PV sites compared to more confined and often incomplete lesions after IRF. At the distal PV sites only IRF ablations were grossly identified based on focal fibrosis. Mild pulmonary chronic parenchymal hemorrhage was noted in three left superior pulmonary vein lobes after IRF. Damage to vagus nerves, as well as evidence of esophagus dilation, occurred at sites associated with IRF. In contrast, no lung, vagal nerve, or esophageal injury was observed at PFA sites. In our next paper, Mohamed Diab and associates aimed to assess the safety of ablation for atrial fibrillation (AF) with trans-esophageal (TEE) screening on intracardiac echocardiography (ICE) imaging of the appendage in direct oral anticoagulant (DOAC) compliant patients. They studied 900 patients with a medium CHA2DS2-VASc score of two. Interquartile range one to three. All consecutive patients presenting with AF or atrial flutter on DOAC were included. All were on DOACs (333 Rivaroxaban, 285 Dabigatran, 281 Apixaban and one Edoxaban). Thromboembolic complications occurred in four patients (0.3%), two ischemic strokes, one transient ischemic attack without residual deficit and one splenic infarct, all with no further complications. Bleeding complications incurred in 5 patients (0.4%), including 2 pericardial effusions (1 intraoperative, 1 after 30 days, both drained), and 3 groin hematomas (1 due to needing heparin for venous thrombosis, none requiring intervention). No patients required emergent surgeries. In our next paper, Alexios Hadjis and associates aim to explore the role of complete diastolic pathway activation mapping on ventricular tachycardia (VT) recurrence. They studied 85 consecutive patients who underwent VT ablation using and guided by high-density mapping. During activation mapping, the presence of electrical activity in all segments of diastole defined the evidence of having had recorded the whole diastolic interval. Patients were categorized as having recorded the full diastolic pathway, partial diastolic pathway or no diastolic pathway map performed. Recurrences of VT were defined as appropriate IC therapies or on the basis of EC documented arrhythmia. Complete recording of the diastolic pathway was achieved in 36 of 85 (42.4%). Partial recording of the diastolic pathway of clinical VT was achieved in 24 of 85 (28.2%). No recording of the diastolic pathway of clinical VT was feasible in 25 of 85 patients (29.4%). At a mean of 12.8 months, freedom from VT recurrences was 67% in the overall cohort. At a mean of 12.8 months, freedom from VT recurrence was 88% in patients who had full diastolic activity recorded, 50% of partial diastolic activity recorded and 55% in those who underwent substrate modification (P=0.02). The authors concluded that mapping of the entire diastolic pathway was associated with a higher freedom from VT occurrence compared to partial diastolic pathway recording and substrate modification. The use of multielectrode mapping catheters in recording diastolic activity may help predict those VTs employing intramural circuits and further optimize ablation strategies. In our next paper, Hui-Nam Pak and associates investigated whether electrical posterior box isolation (POBI) may improve rhythm outcome of catheter ablation in patients in whom persistent atrial fibrillation changes to paroxysmal atrial fibrillation after antiarrythmic drug medication and cardioversion. They prospectively randomized 114 patients, 75% male, 59.8 years old to circumferential pulmonary vein ablation (CPVI) alone (n=57) and an additional POBI group (n=57). Primary endpoint was AF recurrence after a single procedure, and secondary endpoints were recurrence pattern, cardioversion rate and response to antiarrhythmic drugs (AAD). After a mean follow-up of 23.8 months, the clinical recurrence rate did not significantly differ between the CPVI alone and additional POBI group (31.6% versus 28.1%; P=0.682). The recurrence rate as atrial tachycardias, 5.3% versus 12.3% (P=0.14) and cardioversion rates, 5.3% versus 10.5% (P=0.25) were not significantly different between the CPVI and POBI group. At the final follow-up, sinus rhythm was maintained without antiarryhthmic drug in 52.6% of CPVI group and 59.6% of the POBI group (P=0.45). No significant difference was found in major complications between the two groups, 5.3% versus 1.8% (P=0.618). But the total ablation time was significantly longer in the POBI group (4187 seconds versus 5337 seconds; P

Circulation: Arrhythmia and Electrophysiology September 2020 Issue

Paul J. Wang: Welcome to the monthly podcast, On the BEAT, for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, Editor in Chief, with some of the key highlights from this month's issue. Albert Feeny and Associates used unsupervised machine learning of electrocardiogram [ECG] waveforms to identify cardiac resynchronization therapy [CRT] subgroups to differentiate outcomes beyond QRS duration and left bundle branch block. They retrospectively analyzed 946 CRT patients with conduction delay. Principal component analysis [PCA] dimensionality reduction obtained a 2-dimensional representation of pre-CRT 12-lead QRS waveforms. K-means clustering of the 2-dimensional PCA representation of 12-lead QRS waveforms identified two patient subgroups [QRS PCA groups]. Vectorcardiographic QRS area was also calculated. They examined two primary outcomes: (1) composite endpoint of death, left ventricular assist device, or heart transplant, and (2) degree of echocardiographic left ventricular ejection fraction [LVEF] change after CRT. Compared to QRS PCA group 2 (n = 425), Group 1 (n=521) had a lower risk for achieving the composite endpoint (hazard ratio of 0.44, P < 0.001) and experienced greater mean LVEF improvement (11.1% versus 4.8%, P < 0.001), even among left bundle branch block patients with QRS duration, 150 milliseconds or greater (hazard ratio 0.45, P < 0.001; mean LVF change 12.5% versus 7.3%, P=0.001). A stratification scheme combining QRS area and QRS PCA group identified left bundle branch block patients with similar outcomes as non left bundle branch block patients (hazard ratio 1.32, mean difference LVEF change 0.8%). That stratification scheme also identified left bundle branch block patients with QRS duration less than 150 ms is comparable outcomes to left bundle branch patients with QRS duration 150 ms or greater (hazard ratio 0.93, mean difference in LVF change -0.2%). The authors concluded that unsupervised machine learning of ECG waveforms identified CRT subgroups with relevance beyond left bundle branch block and QRS duration. In our next paper, Julie Shade, Rheeda Ali and Associates combined machine learning [ML] and personalized computational modeling to predict, prior to pulmonary vein isolation [PVI], which patients are most likely to experience atrial fibrillation [AF] recurrence after PVI. The single center retrospective proof of concept study included 32 patients with documented paroxysmal AF who underwent PVI and had pre-procedural late gadolinium enhanced magnetic resonance imaging [LGE MRI]. For each patient, a personalized computational model of the left atrium simulated AF induction via rapid pacing features were derived from pre-PVI LG MRI images and from results of simulations [SIM] AF. The most predictive features used to input to a quadratic discrimination analysis ML classifier, which was trained, optimized, and evaluated with a 10-fold nested cross validation to predict the probability of AF recurrence post PVI. In the cohort, the ML classifier predicted probability of AF recurrence with an average validation, sensitivity, and specificity of 82% and 89% respectively, and a validation AUC of 0.82. Dissecting the relative contributions of simulations SIM AF and raw images to the predictive capability of the ML classifier, they found that only when features from simulation SIM AF were used to train the ML classifier, its performance retained similar (validation AUC equals 0.81). However, when only features classified from raw images were used for training, the validation AUC significantly decreased (0.47). In our next paper, Sarah Vermij and Associates examined sodium channel NaV 1.5 localization and function mutations in the gene and coding the sodium channel NaV 1.5 caused various cardiac arrhythmias. The authors use novel single-molecule localization [S-M-L-M] and computational modeling to define nanoscale features of NaV 1.5 localization and distribution at the lateral membrane [L-M], the LM groove, and T-tubules in cardiomyocytes from wild-type (N=3), dystrophin-deficient (mdx; N=3) mice, and mice expressing C-terminally truncated NaV 1.5 (ΔSIV; N=3). The authors assessed T-tubules sodium current by recording whole-cell sodium currents in control (N=5) in detubulated (N=5) wild-type cardiomyocytes. The authors found that NaV 1.5 organizes as distinct clusters in the groove and T-tubules which density, distribution, and organization partially depend on SIV and dystrophin. They found that overall reduction in NaV 1.5 expression expressed in mdx and ΔSIV cells result in a non-uniform distribution with NaV 1.5 being specifically reduced at the groove ΔSIV and increased in T-tubules of mdx cardiomyocytes. A T-tubules sodium current could, however, not be demonstrated. The authors concluded that NaV 1.5 mutations may site-specifically affect NaV 1.5 localization and distribution at the lateral membrane and T-tubules, depending on site-specific interacting proteins. In our next paper, Sharan Sharma, Mohit Turagam, and associates studied strategies to improve patient comfort related to pericardial access. They conducted a multi-centered retrospective study, including 104 patients who underwent epicardial ventricular tachycardia [VT] ablation and Lariat left atrial appendage occlusion. They compared 53 patients who received post-procedural intrapericardial liposomal bupivacaine (LB)+oral colchicine (LB group) and 51 patients who received colchicine alone (non-LB group). Lyposomal bupivacaine was associated with significant lowering of median pain scale at 6 hours (1.0 versus 8.0, P

<description>&lt;p&gt;Paul J. Wang:&lt;/p&gt; &lt;p&gt;Welcome to the monthly podcast, On the BEAT, for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, Editor in Chief, with some of the key highlights from this month's issue.&lt;/p&gt; &lt;p&gt;Albert Feeny and Associates used unsupervised machine learning of electrocardiogram [ECG] waveforms to identify cardiac resynchronization therapy [CRT] subgroups to differentiate outcomes beyond QRS duration and left bundle branch block. They retrospectively analyzed 946 CRT patients with conduction delay. Principal component analysis [PCA] dimensionality reduction obtained a 2-dimensional representation of pre-CRT 12-lead QRS waveforms. K-means clustering of the 2-dimensional PCA representation of 12-lead QRS waveforms identified two patient subgroups [QRS PCA groups]. Vectorcardiographic QRS area was also calculated. They examined two primary outcomes: (1) composite endpoint of death, left ventricular assist device, or heart transplant, and (2) degree of echocardiographic left ventricular ejection fraction [LVEF] change after CRT. Compared to QRS PCA group 2 (n = 425), Group 1 (n=521) had a lower risk for achieving the composite endpoint (hazard ratio of 0.44, P &lt; 0.001) and experienced greater mean LVEF improvement (11.1% versus 4.8%, P &lt; 0.001), even among left bundle branch block patients with QRS duration, 150 milliseconds or greater (hazard ratio 0.45, P &lt; 0.001; mean LVF change 12.5% versus 7.3%, P=0.001). A stratification scheme combining QRS area and QRS PCA group identified left bundle branch block patients with similar outcomes as non left bundle branch block patients (hazard ratio 1.32, mean difference LVEF change 0.8%). That stratification scheme also identified left bundle branch block patients with QRS duration less than 150 ms is comparable outcomes to left bundle branch patients with QRS duration 150 ms or greater (hazard ratio 0.93, mean difference in LVF change -0.2%). The authors concluded that unsupervised machine learning of ECG waveforms identified CRT subgroups with relevance beyond left bundle branch block and QRS duration.&lt;/p&gt; &lt;p&gt;In our next paper, Julie Shade, Rheeda Ali and Associates combined machine learning [ML] and personalized computational modeling to predict, prior to pulmonary vein isolation [PVI], which patients are most likely to experience atrial fibrillation [AF] recurrence after PVI. The single center retrospective proof of concept study included 32 patients with documented paroxysmal AF who underwent PVI and had pre-procedural late gadolinium enhanced magnetic resonance imaging [LGE MRI]. For each patient, a personalized computational model of the left atrium simulated AF induction via rapid pacing features were derived from pre-PVI LG MRI images and from results of simulations [SIM] AF. The most predictive features used to input to a quadratic discrimination analysis ML classifier, which was trained, optimized, and evaluated with a 10-fold nested cross validation to predict the probability of AF recurrence post PVI. In the cohort, the ML classifier predicted probability of AF recurrence with an average validation, sensitivity, and specificity of 82% and 89% respectively, and a validation AUC of 0.82. Dissecting the relative contributions of simulations SIM AF and raw images to the predictive capability of the ML classifier, they found that only when features from simulation SIM AF were used to train the ML classifier, its performance retained similar (validation AUC equals 0.81). However, when only features classified from raw images were used for training, the validation AUC significantly decreased (0.47).&lt;/p&gt; &lt;p&gt;In our next paper, Sarah Vermij and Associates examined sodium channel NaV 1.5 localization and function mutations in the gene and coding the sodium channel NaV 1.5 caused various cardiac arrhythmias. The authors use novel single-molecule localization [S-M-L-M] and computational modeling to define nanoscale features of NaV 1.5 localization and distribution at the lateral membrane [L-M], the LM groove, and T-tubules in cardiomyocytes from wild-type (N=3), dystrophin-deficient (mdx; N=3) mice, and mice expressing C-terminally truncated NaV 1.5 (ΔSIV; N=3). The authors assessed T-tubules sodium current by recording whole-cell sodium currents in control (N=5) in detubulated (N=5) wild-type cardiomyocytes. The authors found that NaV 1.5 organizes as distinct clusters in the groove and T-tubules which density, distribution, and organization partially depend on SIV and dystrophin. They found that overall reduction in NaV 1.5 expression expressed in mdx and ΔSIV cells result in a non-uniform distribution with NaV 1.5 being specifically reduced at the groove ΔSIV and increased in T-tubules of mdx cardiomyocytes. A T-tubules sodium current could, however, not be demonstrated. The authors concluded that NaV 1.5 mutations may site-specifically affect NaV 1.5 localization and distribution at the lateral membrane and T-tubules, depending on site-specific interacting proteins.&lt;/p&gt; &lt;p&gt;In our next paper, Sharan Sharma, Mohit Turagam, and associates studied strategies to improve patient comfort related to pericardial access. They conducted a multi-centered retrospective study, including 104 patients who underwent epicardial ventricular tachycardia [VT] ablation and Lariat left atrial appendage occlusion. They compared 53 patients who received post-procedural intrapericardial liposomal bupivacaine (LB)+oral colchicine (LB group) and 51 patients who received colchicine alone (non-LB group). Lyposomal bupivacaine was associated with significant lowering of median pain scale at 6 hours (1.0 versus 8.0, P&lt;0.001), at 12 hours (1.0 versus 6.0, P&lt;0.001), and up to 48 hours post-procedure. Incidence of acute severe pericarditis delayed pericardial effusion and gastrointestinal adverse effects were similar in both groups. Median length of stay was significantly lower in the lyposomal bupivacaine pain group (2.0 versus 3.0, P&lt;0.001). Subgroup analysis demonstrated similar favorable outcomes in both Lariat and epicardial VT ablation groups.&lt;/p&gt; &lt;p&gt;In our next paper, Sergio Callegari, Emilio Macchi, and Associates characterize the fibrosis (amount, architecture, cellular components, and ultrastructure) in left atrial biopsies from 121 patients with persistent/long-lasting atrial fibrillation [AF] (group 1; 59 males; 60 years of age; 91 mitral disease-related AF, 30 nonmitral disease-related AF) and 39 patients in sinus rhythm with mitral valve regurgitation (group 2; 32 males; 59 years of age). 10 autopsy hearts served as controls. Qualitatively, the fibrosis exhibited the same characteristics in all cases and displayed particular architectural scenarios (which the authors arbitrarily divided into four stages) ranging from isolated foci to confluent sclerotic areas. The percentage of fibrosis was larger and in a more advanced stage in group 1 versus group 2 and within group 1, in patients with rheumatic disease versus non-rheumatic cases. In AF patients with mitral disease and no rheumatic disease, the percentage of fibrosis and the fibrosis stages correlated with both left atrial volume index and AF duration. The fibrotic areas mainly consisted of type I collagen with only a minor cellular component (especially fibroblasts/myofibroblasts; average value range 69–150 cells/mm2, depending on the areas in AF biopsies). A few fibrocytes, circulating and bone marrow-derived mesenchymal cells, were also detectable. The fibrosis-entrapped cardiomyocytes showed sarcolemmal damage and connexin 43 redistribution/internalization.&lt;/p&gt; &lt;p&gt;In our next paper, Shijie Zhou and Associates tested an automated localization system to identify the site of origin of left ventricular [LV] activation in real time using 12-lead ECG. The automated site of origin, solo system, consists of three steps: (1) localization of ventricular segment based on population templates, (2) population-based localization within a segment, and, (3) patient-specific site localization. Localization error was assessed by the distance between the known reference site and the estimated site. In 19 patients undergoing 21 catheter ablation procedures of scar related VT, solo accuracy was estimated using 552 LV left endocardial pacing sites pooled together and 25 VT-exit sites identified by contact mapping. For the 25 VT-exit sites, localization error of the population-based localization steps was within 10 mm. Patient-specific site localization achieved accuracy of within 3.5 mm after including up to 11 pacing (training) sites. Using 3 remotes (67.8 mm from the reference VT-exit site), and then 5 close pacing sites, resulted in localization error of 7.2 mm for the 25 identified VT-exit sites. In 2 emulated clinical procedure with 2 induced VT's, the solo system achieved accuracy within 4 mm.&lt;/p&gt; &lt;p&gt;In our next paper, Ryan Koene and associates examined outcomes of use of dofetilide in atrial fibrillation [AF] patients with left ventricular ejection fraction [LVEF]≤35% without prior implantable cardioverter defibrillator [ICD] cardiac resynchronization therapy [CRT], or AF ablation. An analysis of 168 consecutive patients from 2007 to 2016 was performed. Incidences of adverse events, drug discontinuation, ICD, or CRT implementation, LVEF improvement (&gt;35%) and recovery (50% or greater), AF recurrence, and AF ablation were determined. Multi-variate regression analysis to identify predictors of LVEF improvement/recovery was performed. The mean age was 64 years. Dofetilide was discontinued prior to hospital discharge in 46 (27%) because of QT prolongation (14%), torsades de pointe or polymorphic ventricular tachycardia/ventricular fibrillation (6% [sustained 3%, nonsustained 3%]), in effectiveness (5%), and other causes (3%). At one year 43% remained on dofetilide. Freedom from AF was 42% at 1 year and 40% underwent future AF ablation. LVEF recovered to 50% or greater in 45% and an improved to greater than 35% in 73%. Predictors of LVEF improvement included presence of AF during echocardiogram (odds ratio 4.22, P=0.002), coronary artery disease (odds ratio 0.35, P=0.01), left atrial diameter (odds ratio, 0.52 per 1 cm increase, P=0.01), and LVEF (odds ratio, per 1% increase, 1.09, P=0.006). The C statistic was 0.78.&lt;/p&gt; &lt;p&gt;Our next paper is a research letter by Giuseppe Ciliberti, Gherardo Finocchiaro, and Associates. Myocardial infarction with nonobstructive coronary arteries, MINOCA, accounts for one to 10% of all causes of acute myocardial infarction [MI]. The authors examine 37, that is 0.7% of the entire study population, sudden cardiac death cases of MINOCA. The majority of decedents were male (N=23, 62%), mean age at death was 34 years, age range 13 to 96 years. Death occurred at rest or during daily activities in 36, that is 97% of individuals. Coronary thrombosis was found at 9 out of 13 at a 69% with nonobstructive atherosclerosis. Drug use was reported in 10 or 27%.&lt;/p&gt; &lt;p&gt;Our next paper is a special report entitled HRS/EHRA/APHRS/LAHRS/ACC/AHA worldwide practice update for tele-health and arrhythmia monitoring during and after a pandemic. This document discusses how digital health may facilitate electrophysiology practice in patients with arrhythmia. Electrophysiology is well placed for virtual consultation. Digital tools such as direct to consumer mobile ECG and wireless blood pressure devices can be used to further compliment the tele-health visit without in-person contact C-I-E-D wearable mobile health and clinical data can be integrated into clinician workflow. Wearable and smart flow based devices allow convenient real-time monitoring for arrhythmias. Remote CID monitoring has a continue important role. Our special report is entitled Guidance for Rebooting Electrophysiology Through COVID-19 Pandemic from the Heart Rhythm Society and the American Heart Association, Electrocardiography and Arrhythmias Committee of the Council on Clinical Cardiology endorsed by the American College of Cardiology. Dhanunjaya Lakkireddy, Mina Chung and Associates in this joint document for representatives of the Heart and Society, American Heart Association, American College of Cardiology, provide guidance for clinicians, institutions establishing safe electrophysiological care. To achieve the same they address regional and local COVID-19 disease status, the role of viral screening, and serologic testing, return to work considerations for exposed and infected healthcare workers, risk stratification and management strategy based on COVID-19 disease burden, institutional preparedness for resumption of elective procedures, patient preparation and communication, prioritization of procedures and development of outpatient and periprocedural care pathways.&lt;/p&gt; &lt;p&gt;In a special report, Philip Krisai and Associates reported the results of CONVERT-AF (Canakinumab for the Prevention of Recurrences After Electrical Cardioversion in Patients With Persistent Atrial Fibrillation) is a randomized double blind placebo control trial enrolling patients with persistent A-Fib, atrial fibrillation, AF undergoing electrical cardioversion, or ECV with HS CRP levels of two mg/L or greater. Age, greater than 50 years of age women needed to be post-menopausal. After sinus rhythm restoration, patients were randomly assigned within 60 minutes to a single subcutaneous injection of 150 mg of Canakinumab or matching placebo. 11 and 13 patients were randomized to Canakinumab and placebo rest respectively mean overall age was 66 years, 24% women. AF recurrence in six months occurred in 10 (77%) and four (36%) in patients with the placebo or Canakinumab groups, respectively (hazard ratio 0.36, P=0.09). At one month AF recurred in six (46%) and four (36%); at three months in eight (62%) and four (36%) patients respectively. The hazard ratios for first time redo ECV and hospitalization-free survival were 0.29 (P=0.27) and 0.74 (P=0.75) respectively and antiarrhythmic drug use at 6 months were used in 7 (54%) and 9 (82%) of patients in the placebo and the Canakinumab group respectively. Odds ratio 3.86 P equals 0.16 log transform high sensitivity CRP was 31% lower in the Canakinumab group. At six months, adverse events occurred in 3 (23%) and 3 (27%) in the placebo and Canakinumab groups, respectively. Infections occurred in 2 (15%) and 2 (18%) in the placebo and Canakinumab groups respectively.&lt;/p&gt; &lt;p&gt;In a special report Amr Barakat and associates reported that the number of implants of SelectSecure 3830 [SS3830] increase greater than 4-fold in 2017 (9,145) and 2018 (9,895) compared to 2016 (1,972 implants). The yearly number of his bundle pacing related publications increased approximately 4-fold in 2015 and approximately 25-fold in 2018, compared to 2014. 140 medical device reports related to SS3830 lead use were made for permanent his bundle pacing.&lt;/p&gt; &lt;p&gt;That's it for this month. We hope that you'll find the journal to be the go-to place for everyone interested in the field. See you next time... this program is copyright American heart association, 2020.&lt;/p&gt; &lt;p&gt; &lt;/p&gt;</description>

Circulation: Arrhythmia and Electrophysiology July 2020 Issue

Paul J. Wang: Welcome to the monthly podcast, On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. In our first paper, Bruce Wilkoff and associates examine the impact of cardiac implantable electronic device [CIED] infections on mortality, quality of life, healthcare utilization, and cost in the U.S. Healthcare system. They found that the majority CIED infection was associated with increased all-cause mortality, 12-month risk-adjusted hazard ratio 3.41, P < 0.001. An effect that sustained beyond 12 months.   The quality of life was reduced, P = 0.004, and did not normalize for six months. Disruptions in CIED therapy were observed in 36% of infections for a median duration of 184 days. The authors reported that the mean hospital costs were $55,547.   In our next paper, Songwen Chen, Xiaofeng Lu and associates examine the ability to eliminate premature ventricular complexes [PVCs] originating from the proximal left anterior fascicle, safely from the right coronary sinus. The authors mapped the the right coronary sinus and left ventricle in 20 patients with left anterior fascicle PVCs. They found that the earliest activation site with Purkinje potential during both PVC and sinus rhythm was localized at proximal left anterior fascicle in eight patients, the proximal group, or non-proximal left anterior fascicle in 12 groups, the non-proximal group. The Purkinje potentials proceeded PVC-QRS at the earliest activation site in proximal group 32.6 milliseconds was significantly earlier than that in non-proximal group, 28.3 milliseconds P = 0.025. Similar difference in the Purkinje potentials proceeding sinus QRS at the earliest activation site was also observed between proximal and non-proximal group, 35.1 milliseconds versus 25.2 milliseconds, P < 0.001.   In proximal group, the distance between the earliest activation site to the left His-bundle into the right coronary sinus were shorter than that of the non-proximal group 12.3 millimeters versus 19.7, P = 0.002, and 3.9 millimeters versus 15.7 millimeters, P < 0.001, respectively. The authors found no difference in the distance between the right coronary sinus to proximal left anterior fascicle between the two groups. PVCs were successfully eliminated from the right coronary sinus in all proximal group, but at left ventricular earliest activation site for the non-proximal group, the radiofrequency application time, ablation time and procedure time of non-proximal group were longer than that proximal group.   Electrocardiographic analysis showed that when compared to non-proximal group, the PVCs proximal group had a narrower QRS duration, smaller S wave in leads one, V five,and V six; lower R waves in leads one, aVL, aVR, V one, V two, and V four and smaller q wave in leads three and aVF. The QRS duration difference [PVC-QRS and sinus rhythm QRS] < 15 milliseconds predicted the proximal left anterior fascicle origin with high sensitivity and specificity.   In our next paper, Benjamin Steinberg and associates examined the factors that are associated with large improvements in health-related quality of life in patients with atrial fibrillation. The authors assessed factors associated with a one-year increase in quality of life, measured by AFEQT of one standard deviation that is greater and equal to 18 points, three times clinically important difference among patients in the ORBIT-AF one registry. They found that 28% of patients had such a health-related quality improvement compared with patients not showing large health-related quality of life improvement. They were similar age, (median 73 versus 74 years of age), equally likely to be female, (44% versus 48%), but more likely to have newly diagnosed atrial fibrillation [AF] at baseline (18% versus 8%, P = 0.0004) prior antiarrhythmic drug use (52% versus 40%, P = 0.005), baseline antiarrhythmic drug use (34.8% versus 26.8%, P = 0.045), and more likely to undergo AF related procedures during follow-up (AF ablation 6.6% versus 2.0%, cardioversion 12.2% versus 5.9%). In multivariate analysis, a history of alcohol abuse has a ratio 2.4 and increased baseline diastolic blood pressure has a ratio 1.23 per 10 point increase and greater than 65 millimeters of mercury were associated with large improvements in health-related quality of life at one year. Whereas patients with prior stroke, chronic obstructive pulmonary disease and peripheral artery disease were less likely to improve.   In our next paper, Eiichi Watanabe and associates studied safety and resource consumption of exclusive remote follow-up in pacemaker patients for two years. Consecutive pacemaker patients committed to remote pacemaker management were randomized to either remote follow-up or conventional in-office follow-up at twice yearly intervals.   Remote follow-up patients were only seen if indicated by remote monitoring, all returned to hospital after two years. In 1,274 randomized patients (50.4% female, age 77 years), 558 remote follow-up or 550 conventional in office follow-up patients reached either the primary end point or 24 months follow-up. The primary end point, a composite of death, stroke, or cardiovascular events requiring surgery occurred in 10.9% and 11.8% respectively in the two groups (P = 0.0012) for non-inferiority. The median number of in-office follow-ups was 0.5 in the remote follow-up group and 2.01 in the conventional in-office follow-up per patient year (P < 0.001). Only 1.4% of remote follow-ups triggered an unscheduled in-office follow-up, and only 1.5% of scheduled in-office follow-ups were considered actionable.   In our next paper, Sarah Strand and associates use fetal magnetocardiography from the University of Wisconsin biomagnetism laboratory to study 39 fetuses with pathogenic variants in long QT syndrome, LQTS genes. 27 carried the family variant, 11 had de novo variants, and one was indeterminant. De novo variants, especially de novo SCN5A variants were strongly associated with a severe rhythm phenotype and perinatal death. Nine or 82% showed signature LQTS rhythms, six showed torsade de pointes, five were still born, and 9% died in infancy. Those that died exhibited novel fetus rythms, including AV block with 3:1 conduction ratio, QRS alternans in 2:1 AV block, long cycle length, torsade de pointes, and slow monomorphic ventricular tachycardia. Premature ventricular contractions were also strongly associated with torsade de pointes and perinatal death. Fetuses with familiar variants showed a lower incidence of signature LQTS rhythm, six out of 27 or 22%, including torsade de pointes, and 3 out of 27 or 11% all were live born. The authors concluded that the malignancy of de novo LQTS variants was remarkably high and demonstrate that these mutations are a significant cause of stillbirth.   In our next paper, Corina Schram-Serban and associates compare the severity of extensiveness of conduction disorders between obese patients and non-obese patients measured at high resolution scale. They studied 212 patients undergoing cardiac surgery (male:161, mean 63 years of age), who underwent epicardial mapping of the right atrium, Bachmann's bundle, and left atrium during sinus rhythm. Conduction delay [CD] was defined as interelectrode conduction time seven to 11 milliseconds and conduction block [CB] as conduction time ≥ 12 milliseconds. In obese patients, the overall incidence of conduction delay was 3.1% versus 2.6% (P = 0.002), conduction block 1.8% versus 1.2%, and continuous CDCB 2.6% versus 1.9% higher in the obese patients, conduction delay (P = 0.012) and continuous CDCB lines are longer. There were more conduction disorders at Bachman's bundle, and this area has a higher incidence of conduction delay 4.4% versus 3.3% (P = 0.002), conduction block 3.1% versus 1.6% (P < 0.001), continuous conduction block conduction delay 4.6% versus 2.7% and longer conduction delay or conduction delay conduction block lines. Severity of conduction block is also higher, particularly in the Bachmann bundle and pulmonary vein areas. In addition, obese patients have a higher incidence of early de novo postoperative atrial fibrillation. Body mass index and the overall amount of conduction block were independent predictors for the incidents of early postoperative atrial fibrillation.   In our next paper, Ricardo Cardona-Guarache and associates describe five patients with concealed, left-sided nodoventricular in four patients and nodofascicular in one patient accessory pathways. They proved the participation of accessory pathway in tachycardia by delivering His-synchronous premature ventricular complexes that either delayed the subsequent atrial electrogram or terminated the tachycardia, and by observing an increase in ventricular atrial interval coincident with left bundle branch block in two patients. The accessory pathways were not atrioventricular pathways because the septal ventricular atrial interval during tachycardia was less than 70 milliseconds in 3, 1 had spontaneous AV dissociation, and in 1 the atria were dissociated from the circuit with atrial overdrive pacing.   Entrainment from the right ventricle showed ventricular fusion in 4 out of 5 cases. A left-sided origin of accessory pathways was suspected after failed ablation of the right inferior extension of the AV node in 3 cases and by observing VA increase in left bundle branch block in 2 cases. The nodofascicular in 3 of the 4 nodoventricular accessory pathways were successfully ablated from within the proximal coronary sinus guided by recorded potentials at the roof of the coronary sinus, and nodoventricular accessory pathway was ablated via a transseptal approach near the coronary sinus os.   In our next paper, Pierre Qian and associates examined whether an open irrigated microwave catheter ablation can achieve deep myocardial lesions endocardially and epicardially through fat while acutely sparing nearby coronary arteries. Epicardial ablations via subxiphoid access in pigs were performed at 90 to 100 Watts at four minutes at sites near coronary arteries and produced mean lesion depth of 10 millimeters, width 18 millimeters, and length 29 millimeters through median epicardial fat thickness of 1.2 millimeters. Endocardial ablations at 180 Watts achieved depths of 10.7 millimeters, width of 16.6 millimeters, and length of 20 millimeters. Acute coronary occlusion or spasm was not observed at median separation distance of 2.7 millimeters.   In our next paper, Jad Ballout and associates examined 21 consecutive patients with cardiogenic shock and refractory ventricular arrhythmias undergoing bailout ablation due to inability to wean off of mechanical support. Mean age was 61 years, 86% were males, median left ventricular injection fraction 20%, 81% ischemic cardiomyopathy. The type of mechanical support in place prior to the procedure was intra-aortic balloon pump in 14 patients, Impella in 2, ECMO in 2, ECMO and intra-aortic balloon pump in 2, and ECMO and Impella in 1. In the cardio voltage maps with myocardial scar in 90% (19 patients), the clinical ventricular tachycardias VTs were inducible in 13% (62 patients), whereas 6 patients had PVC induced ventricular fibrillation, VT (29%), and VT could not be induced in 2 patients (9%). Activation mapping was possible in all 13 patients with inducible clinical VTs, substrate modification was performed in 15 patients with scar in 79%. After ablation and scar modification, the arrhythmia was noninducible in 19 patients (91%). Seventeen (81%) were eventually weaned off mechanical support successfully with the majority of patients being discharged home and surviving beyond one year. However, 6 (29%) died during the index admission with persistent cardiogenic shock.   In a research letter, Parveen Garg and associates examined the multi-ethnic study of atherosclerosis [MESA] incident atrial fibrillation a population with 50% African-American or Hispanic. After adjusting for age, race, ethnicity, sex education, income, clinic site, height, body, mass index, cigarette, smoking, diabetes, systolic and diastolic blood pressure, and hypertensive medications, physical activity, alcohol consumption, lipid parameter to lipid lowering therapy, the baseline lipoprotein A level greater or equal to 30 milligram per deciliter was inversely associated with developing atrial fibrillation compared those with lower levels (hazard ratio 0.84). However, the mechanism of this paradoxical association is unclear.   In another research letter, Yoshihide Takahashi and associates reported that 49 patients undergoing ablation of persistent atrial fibrillation had at least one focal site and rotational activation in 57%. Of these, 19 patients underwent a repeat ablation for recurrent atrial fibrillation. AF was mapped in 17 patients and 131 focal activation sites were ablated. There were 105 displayed focal activation sites during the de novo ablation and 89 focal activation sites during the repeat ablation. During the de novo ablation, rotation activation was observed in 19 sites. Of the 19 sites, 12 (63%) displayed rotational activity, also with the repeat ablation. The author suggested focal or rotational activation sites can be classified into two types, ones critical for AF recurrence and the ones that are bystander.   That's it for this month. We hope that you'll find the journal to be the go-to place for everyone interested in the field. See you next time.   This program is copyright American Heart Association, 2020.   Correction: In the study by Pierre Qian and associates, the epicardial ablations via subxiphoid access were performed in sheep, not pigs, as previously stated.

<description>&lt;p&gt;Paul J. Wang:&lt;/p&gt; &lt;p&gt;Welcome to the monthly podcast, On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. In our first paper, Bruce Wilkoff and associates examine the impact of cardiac implantable electronic device [CIED] infections on mortality, quality of life, healthcare utilization, and cost in the U.S. Healthcare system. They found that the majority CIED infection was associated with increased all-cause mortality, 12-month risk-adjusted hazard ratio 3.41, P &lt; 0.001. An effect that sustained beyond 12 months.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;The quality of life was reduced, P = 0.004, and did not normalize for six months. Disruptions in CIED therapy were observed in 36% of infections for a median duration of 184 days. The authors reported that the mean hospital costs were $55,547.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In our next paper, Songwen Chen, Xiaofeng Lu and associates examine the ability to eliminate premature ventricular complexes [PVCs] originating from the proximal left anterior fascicle, safely from the right coronary sinus. The authors mapped the the right coronary sinus and left ventricle in 20 patients with left anterior fascicle PVCs. They found that the earliest activation site with Purkinje potential during both PVC and sinus rhythm was localized at proximal left anterior fascicle in eight patients, the proximal group, or non-proximal left anterior fascicle in 12 groups, the non-proximal group. The Purkinje potentials proceeded PVC-QRS at the earliest activation site in proximal group 32.6 milliseconds was significantly earlier than that in non-proximal group, 28.3 milliseconds P = 0.025. Similar difference in the Purkinje potentials proceeding sinus QRS at the earliest activation site was also observed between proximal and non-proximal group, 35.1 milliseconds versus 25.2 milliseconds, P &lt; 0.001.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In proximal group, the distance between the earliest activation site to the left His-bundle into the right coronary sinus were shorter than that of the non-proximal group 12.3 millimeters versus 19.7, P = 0.002, and 3.9 millimeters versus 15.7 millimeters, P &lt; 0.001, respectively. The authors found no difference in the distance between the right coronary sinus to proximal left anterior fascicle between the two groups. PVCs were successfully eliminated from the right coronary sinus in all proximal group, but at left ventricular earliest activation site for the non-proximal group, the radiofrequency application time, ablation time and procedure time of non-proximal group were longer than that proximal group.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;Electrocardiographic analysis showed that when compared to non-proximal group, the PVCs proximal group had a narrower QRS duration, smaller S wave in leads one, V five,and V six; lower R waves in leads one, aVL, aVR, V one, V two, and V four and smaller q wave in leads three and aVF. The QRS duration difference [PVC-QRS and sinus rhythm QRS] &lt; 15 milliseconds predicted the proximal left anterior fascicle origin with high sensitivity and specificity.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In our next paper, Benjamin Steinberg and associates examined the factors that are associated with large improvements in health-related quality of life in patients with atrial fibrillation. The authors assessed factors associated with a one-year increase in quality of life, measured by AFEQT of one standard deviation that is greater and equal to 18 points, three times clinically important difference among patients in the ORBIT-AF one registry. They found that 28% of patients had such a health-related quality improvement compared with patients not showing large health-related quality of life improvement. They were similar age, (median 73 versus 74 years of age), equally likely to be female, (44% versus 48%), but more likely to have newly diagnosed atrial fibrillation [AF] at baseline (18% versus 8%, P = 0.0004) prior antiarrhythmic drug use (52% versus 40%, P = 0.005), baseline antiarrhythmic drug use (34.8% versus 26.8%, P = 0.045), and more likely to undergo AF related procedures during follow-up (AF ablation 6.6% versus 2.0%, cardioversion 12.2% versus 5.9%). In multivariate analysis, a history of alcohol abuse has a ratio 2.4 and increased baseline diastolic blood pressure has a ratio 1.23 per 10 point increase and greater than 65 millimeters of mercury were associated with large improvements in health-related quality of life at one year. Whereas patients with prior stroke, chronic obstructive pulmonary disease and peripheral artery disease were less likely to improve.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In our next paper, Eiichi Watanabe and associates studied safety and resource consumption of exclusive remote follow-up in pacemaker patients for two years. Consecutive pacemaker patients committed to remote pacemaker management were randomized to either remote follow-up or conventional in-office follow-up at twice yearly intervals.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;Remote follow-up patients were only seen if indicated by remote monitoring, all returned to hospital after two years. In 1,274 randomized patients (50.4% female, age 77 years), 558 remote follow-up or 550 conventional in office follow-up patients reached either the primary end point or 24 months follow-up. The primary end point, a composite of death, stroke, or cardiovascular events requiring surgery occurred in 10.9% and 11.8% respectively in the two groups (P = 0.0012) for non-inferiority. The median number of in-office follow-ups was 0.5 in the remote follow-up group and 2.01 in the conventional in-office follow-up per patient year (P &lt; 0.001). Only 1.4% of remote follow-ups triggered an unscheduled in-office follow-up, and only 1.5% of scheduled in-office follow-ups were considered actionable.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In our next paper, Sarah Strand and associates use fetal magnetocardiography from the University of Wisconsin biomagnetism laboratory to study 39 fetuses with pathogenic variants in long QT syndrome, LQTS genes. 27 carried the family variant, 11 had de novo variants, and one was indeterminant. De novo variants, especially de novo SCN5A variants were strongly associated with a severe rhythm phenotype and perinatal death. Nine or 82% showed signature LQTS rhythms, six showed torsade de pointes, five were still born, and 9% died in infancy. Those that died exhibited novel fetus rythms, including AV block with 3:1 conduction ratio, QRS alternans in 2:1 AV block, long cycle length, torsade de pointes, and slow monomorphic ventricular tachycardia. Premature ventricular contractions were also strongly associated with torsade de pointes and perinatal death. Fetuses with familiar variants showed a lower incidence of signature LQTS rhythm, six out of 27 or 22%, including torsade de pointes, and 3 out of 27 or 11% all were live born. The authors concluded that the malignancy of de novo LQTS variants was remarkably high and demonstrate that these mutations are a significant cause of stillbirth.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In our next paper, Corina Schram-Serban and associates compare the severity of extensiveness of conduction disorders between obese patients and non-obese patients measured at high resolution scale. They studied 212 patients undergoing cardiac surgery (male:161, mean 63 years of age), who underwent epicardial mapping of the right atrium, Bachmann's bundle, and left atrium during sinus rhythm. Conduction delay [CD] was defined as interelectrode conduction time seven to 11 milliseconds and conduction block [CB] as conduction time ≥ 12 milliseconds. In obese patients, the overall incidence of conduction delay was 3.1% versus 2.6% (P = 0.002), conduction block 1.8% versus 1.2%, and continuous CDCB 2.6% versus 1.9% higher in the obese patients, conduction delay (P = 0.012) and continuous CDCB lines are longer. There were more conduction disorders at Bachman's bundle, and this area has a higher incidence of conduction delay 4.4% versus 3.3% (P = 0.002), conduction block 3.1% versus 1.6% (P &lt; 0.001), continuous conduction block conduction delay 4.6% versus 2.7% and longer conduction delay or conduction delay conduction block lines. Severity of conduction block is also higher, particularly in the Bachmann bundle and pulmonary vein areas. In addition, obese patients have a higher incidence of early de novo postoperative atrial fibrillation. Body mass index and the overall amount of conduction block were independent predictors for the incidents of early postoperative atrial fibrillation.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In our next paper, Ricardo Cardona-Guarache and associates describe five patients with concealed, left-sided nodoventricular in four patients and nodofascicular in one patient accessory pathways. They proved the participation of accessory pathway in tachycardia by delivering His-synchronous premature ventricular complexes that either delayed the subsequent atrial electrogram or terminated the tachycardia, and by observing an increase in ventricular atrial interval coincident with left bundle branch block in two patients. The accessory pathways were not atrioventricular pathways because the septal ventricular atrial interval during tachycardia was less than 70 milliseconds in 3, 1 had spontaneous AV dissociation, and in 1 the atria were dissociated from the circuit with atrial overdrive pacing.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;Entrainment from the right ventricle showed ventricular fusion in 4 out of 5 cases. A left-sided origin of accessory pathways was suspected after failed ablation of the right inferior extension of the AV node in 3 cases and by observing VA increase in left bundle branch block in 2 cases. The nodofascicular in 3 of the 4 nodoventricular accessory pathways were successfully ablated from within the proximal coronary sinus guided by recorded potentials at the roof of the coronary sinus, and nodoventricular accessory pathway was ablated via a transseptal approach near the coronary sinus os.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In our next paper, Pierre Qian and associates examined whether an open irrigated microwave catheter ablation can achieve deep myocardial lesions endocardially and epicardially through fat while acutely sparing nearby coronary arteries. Epicardial ablations via subxiphoid access in pigs were performed at 90 to 100 Watts at four minutes at sites near coronary arteries and produced mean lesion depth of 10 millimeters, width 18 millimeters, and length 29 millimeters through median epicardial fat thickness of 1.2 millimeters. Endocardial ablations at 180 Watts achieved depths of 10.7 millimeters, width of 16.6 millimeters, and length of 20 millimeters. Acute coronary occlusion or spasm was not observed at median separation distance of 2.7 millimeters.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In our next paper, Jad Ballout and associates examined 21 consecutive patients with cardiogenic shock and refractory ventricular arrhythmias undergoing bailout ablation due to inability to wean off of mechanical support. Mean age was 61 years, 86% were males, median left ventricular injection fraction 20%, 81% ischemic cardiomyopathy. The type of mechanical support in place prior to the procedure was intra-aortic balloon pump in 14 patients, Impella in 2, ECMO in 2, ECMO and intra-aortic balloon pump in 2, and ECMO and Impella in 1. In the cardio voltage maps with myocardial scar in 90% (19 patients), the clinical ventricular tachycardias VTs were inducible in 13% (62 patients), whereas 6 patients had PVC induced ventricular fibrillation, VT (29%), and VT could not be induced in 2 patients (9%). Activation mapping was possible in all 13 patients with inducible clinical VTs, substrate modification was performed in 15 patients with scar in 79%. After ablation and scar modification, the arrhythmia was noninducible in 19 patients (91%). Seventeen (81%) were eventually weaned off mechanical support successfully with the majority of patients being discharged home and surviving beyond one year. However, 6 (29%) died during the index admission with persistent cardiogenic shock.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In a research letter, Parveen Garg and associates examined the multi-ethnic study of atherosclerosis [MESA] incident atrial fibrillation a population with 50% African-American or Hispanic. After adjusting for age, race, ethnicity, sex education, income, clinic site, height, body, mass index, cigarette, smoking, diabetes, systolic and diastolic blood pressure, and hypertensive medications, physical activity, alcohol consumption, lipid parameter to lipid lowering therapy, the baseline lipoprotein A level greater or equal to 30 milligram per deciliter was inversely associated with developing atrial fibrillation compared those with lower levels (hazard ratio 0.84). However, the mechanism of this paradoxical association is unclear.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;In another research letter, Yoshihide Takahashi and associates reported that 49 patients undergoing ablation of persistent atrial fibrillation had at least one focal site and rotational activation in 57%. Of these, 19 patients underwent a repeat ablation for recurrent atrial fibrillation. AF was mapped in 17 patients and 131 focal activation sites were ablated. There were 105 displayed focal activation sites during the de novo ablation and 89 focal activation sites during the repeat ablation. During the de novo ablation, rotation activation was observed in 19 sites. Of the 19 sites, 12 (63%) displayed rotational activity, also with the repeat ablation. The author suggested focal or rotational activation sites can be classified into two types, ones critical for AF recurrence and the ones that are bystander.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;That's it for this month. We hope that you'll find the journal to be the go-to place for everyone interested in the field. See you next time.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;This program is copyright American Heart Association, 2020.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;Correction: In the study by Pierre Qian and associates, the epicardial ablations via subxiphoid access were performed in sheep, not pigs, as previously stated.&lt;/p&gt;</description>

Circulation: Arrhythmia and Electrophysiology May 2020 Issue

Each podcast will include key highlights from the journal's current issue and a report on new research published in the field of arrhythmia and electrophysiology.

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