Pathogenesis, Evaluation, and Management of Pulmonary Vein Stenosis: JACC Review Topic of the Week.

Pulmonary vein stenosis (PVS) can arise from several etiologies, including congenital, acquired, and iatrogenic sources. PVS presents insidiously, leading to significant delays in diagnosis. A high index of suspicion and dedicated noninvasive evaluation are key to diagnosis. Once diagnosed, both noninvasive and invasive evaluation may afford further insights into the relative contribution of PVS to symptoms. Treatment of underlying reversible pathologies coupled with transcatheter balloon angioplasty and stenting for persistent severe stenoses are established approaches. Ongoing refinements in diagnostic modalities, interventional approaches, postintervention monitoring, and medical therapies hold promise to further improve patient outcomes.

Causes of Early Mortality After Catheter Ablation of Atrial Fibrillation.

BACKGROUND: Recognition of the causes of early mortality after atrial fibrillation (AF) catheter ablation is essential for the improvement of patient safety. This study sought to determine the causes of early mortality (≤90 days) after AF ablation. METHODS: We performed a retrospective analysis of AF ablation from January 1, 2013, to December 1, 2021 at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Causes of death were identified through a comprehensive chart review of the electronic health record from within the Mayo Clinic system and outside records when available. RESULTS: A total of 6723 patients were included in the study. The 90-day all-cause mortality rate was 0.22% (n=15). Among all 90-day deaths, majority of the deaths (73.3%) did not have a direct relationship with the procedure. Sudden death was the most common cause of early death (20%), followed by peri-procedural stroke (13%), respiratory failure (13%), atrioesophageal fistula (13%), infection (7%), heart failure (7%), and traumatic brain injury (7%). The 90-day mortality rate directly due to AF ablation procedural complications was 0.06% (n=4). CONCLUSIONS: AF ablation procedure has a 90-day mortality of 0.22%, and the most common cause of early mortality was sudden death. The majority (73.3%) of early mortality was not directly associated with a procedural complication, and the mortality rate due to complications associated with the AF ablation procedure was low at 0.06%. Further studies are required to investigate causes and risk factors associated with sudden death in this patient population.

SCAI/HRS Expert Consensus Statement on Transcatheter Left Atrial Appendage Closure.

Exclusion of the left atrial appendage to reduce thromboembolic risk related to atrial fibrillation was first performed surgically in 1949. Over the past 2 decades, the field of transcatheter endovascular left atrial appendage closure (LAAC) has rapidly expanded, with a myriad of devices approved or in clinical development. The number of LAAC procedures performed in the United States and worldwide has increased exponentially since the Food and Drug Administration approval of the WATCHMAN (Boston Scientific) device in 2015. The Society for Cardiovascular Angiography & Interventions (SCAI) has previously published statements in 2015 and 2016 providing societal overview of the technology and institutional and operator requirements for LAAC. Since then, results from several important clinical trials and registries have been published, technical expertise and clinical practice have matured over time, and the device and imaging technologies have evolved. Therefore, SCAI prioritized the development of an updated consensus statement to provide recommendations on contemporary, evidence-based best practices for transcatheter LAAC focusing on endovascular devices.

SCAI/HRS expert consensus statement on transcatheter left atrial appendage closure.

Exclusion of the left atrial appendage to reduce thromboembolic risk related to atrial fibrillation was first performed surgically in 1949. Over the past 2 decades, the field of transcatheter endovascular left atrial appendage closure (LAAC) has rapidly expanded, with a myriad of devices approved or in clinical development. The number of LAAC procedures performed in the United States and worldwide has increased exponentially since the Food and Drug Administration approval of the WATCHMAN (Boston Scientific) device in 2015. The Society for Cardiovascular Angiography & Interventions (SCAI) has previously published statements in 2015 and 2016 providing societal overview of the technology and institutional and operator requirements for LAAC. Since then, results from several important clinical trials and registries have been published, technical expertise and clinical practice have matured over time, and the device and imaging technologies have evolved. Therefore, SCAI prioritized the development of an updated consensus statement to provide recommendations on contemporary, evidence-based best practices for transcatheter LAAC focusing on endovascular devices.

Substrate Characterization and Outcomes of Catheter Ablation of Ventricular Arrhythmias in Patients With Mitral Annular Disjunction.

BACKGROUND: Mitral annular disjunction (MAD) has recently been recognized as an arrhythmogenic entity. Data on the electrophysiological substrate as well as the outcomes of catheter ablation of ventricular arrhythmias in patients with MAD is limited. METHODS: Forty patients with MAD (mean age 47±15 years; 70% female) underwent catheter ablation for ventricular arrhythmias. Detailed clinical, electrocardiographic, cardiac imaging, and procedural data were collected. Clinical outcomes were compared between patients who had substrate modification in the MAD area and those who did not. RESULTS: Twenty-three (57.5%) patients had ablation for premature ventricular contractions, 10 (25%) patients for sustained ventricular tachycardia, and 7 (17.5%) patients for premature ventricular contraction-triggered ventricular fibrillation. Mean end-systolic MAD length was 10.58±3.49 mm on transthoracic echocardiography. Seventeen (42.5%) patients had preprocedural cardiac magnetic resonance imaging, and 5 (29%) patients had late gadolinium enhancement. Among the 18 (45%) patients who had abnormal local electrograms (low voltage, long-duration, fractionated, isolated mid-diastolic potentials) during electroanatomical mapping, 10 (25%) patients had abnormal electrograms in the anterolateral mitral annulus and/or MAD area. Substrate modification was performed in 10 (25%) patients. Catheter ablation was acutely successful in 36 (90%) patients (elimination of premature ventricular contraction or noninducibility of ventricular tachycardia). After a median follow-up duration of 54.08 (interquartile range, 10.67-89.79) months, premature ventricular contraction burden decreased from a median of 9.75% (interquartile range, 3.25-14) before the ablation to a median of 4% (interquartile range, 1-7.75) after the ablation (P=0.03 [95% CI, 0.055-6.5]). Eight (20.5%) patients had repeat ablation for ventricular arrhythmias. Substrate modification of the MAD was associated with a trend toward lower rates of repeat ablation (0% versus 26.7%; P=0.16). CONCLUSIONS: Patients with MAD have a complex arrhythmogenic substrate, and catheter ablation is effective in reducing recurrence of ventricular arrhythmias. Substrate mapping and ablation may be considered in these patients.

Pulmonary Vein Stenosis-Balloon Angioplasty Versus Stenting: A Systematic Review and Meta-Analysis.

Pulmonary vein stenosis (PVS) may arise from a variety of conditions and result in major morbidity and mortality. In some patients, pharmacologic therapy may help, but more often in advanced stages, mechanical treatment must be considered. Transcatheter approaches, both balloon angioplasty (BA) and stent implantation, have been applied. Although both are effective, they continue to be limited by restenosis. In this systematic review and meta-analysis, Ovid MEDLINE, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus were searched for English-language studies in humans published between January 1, 2010, and August 2, 2021. Two independent reviewers screened for studies in which BA or stenting was performed for PVS with reporting of restenosis outcomes, and data were independently extracted. A systematic review was performed, and overall restenosis rates were reported across all 34 included studies. Meta-analysis was then performed using RevMan version 5.4, assessing rates of restenosis and restenosis requiring reintervention in those studies with available data reported. For restenosis rates, 4 studies treated a total of 340 patients with 579 pulmonary vein interventions (225 with BA and 354 with stenting, mean follow-up 13-69 months). Restenosis requiring repeat intervention was reported in 3 studies, including 301 patients with 495 pulmonary vein interventions (157 with BA and 338 with stenting). Compared with BA, stenting was associated with both a lower risk for restenosis (risk ratio: 0.36; 95% CI: 0.18-0.73; P = 0.005) and a lower risk for restenosis requiring reintervention (RR: 0.36; 95% CI: 0.15-0.86; P = 0.02). For PVS intervention, restenosis and reintervention rates may be improved by stent implantation compared with BA.

Temporal Incidence and Predictors of High-Grade Atrioventricular Block After Transcatheter Aortic Valve Replacement.

Background The temporal incidence of high-grade atrioventricular block (HAVB) after transcatheter aortic valve replacement (TAVR) is uncertain. As a result, periprocedural monitoring and pacing strategies remain controversial. This study aimed to describe the temporal incidence of initial episode of HAVB stratified by pre- and post-TAVR conduction and identify predictors of delayed events. Methods and Results Consecutive patients undergoing TAVR at a single center between February 2012 and June 2019 were retrospectively assessed for HAVB within 30 days. Patients with prior aortic valve replacement, permanent pacemaker (PPM), or conversion to surgical replacement were excluded. Multivariable logistic regression was performed to assess predictors of delayed HAVB (initial event >24 hours post-TAVR). A total of 953 patients were included in this study. HAVB occurred in 153 (16.1%). After exclusion of those with prophylactic PPM placed post-TAVR, the incidence of delayed HAVB was 33/882 (3.7%). Variables independently associated with delayed HAVB included baseline first-degree atrioventricular block or right bundle-branch block, self-expanding valve, and new left bundle-branch block. Forty patients had intraprocedural transient HAVB, including 16 who developed HAVB recurrence and 6 who had PPM implantation without recurrence. PPM was placed for HAVB in 130 (13.6%) (self-expanding valve, 23.7% versus balloon-expandable valve, 11.9%; P<0.001). Eight (0.8%) patients died by 30 days, including 1 unexplained without PPM present. Conclusions Delayed HAVB occurs with higher frequency in patients with baseline first-degree atrioventricular block or right bundle-branch block, new left bundle-branch block, and self-expanding valve. These findings provide insight into optimal monitoring and pacing strategies based on periprocedural ECG findings.

Catheter ablation of premature ventricular contractions originating from periprosthetic aortic valve regions.

BACKGROUND: Little is known about the ablation outcomes of premature ventricular contractions (PVCs) that originate from the periprosthetic aortic valve (PPAV) regions of patients with aortic valve replacement (AVR). METHODS AND RESULTS: Our study had 11 patients who underwent catheter ablation for PVCs arising from the PPAV regions (bioprosthetic aortic valve, n = 5; mechanical aortic valve, n = 6). The PVC characteristics, procedure characteristics, and efficacy of ablation were compared with the control group (n = 33). At baseline, the PPAV group had a lower left ventricular ejection fraction (mean [SD], 41% [12%] vs. 51% [8%]; p = .002). The rate of acute ablation success was 90.9% in the PPAV group. Ablation sites were identified above the left coronary cusp (LCC) and right coronary cusp commissure (LRCC) in one PVC, below the prosthetic valve in eight PVCs (four below LCC and four below LRCC), and within the distal coronary sinus in two PVCs. The mean procedure time, fluoroscopy time, and radiation in the PPAV group were all significantly greater than those in the control group (all p < .05). However, the number of radiofrequency ablation energy deliveries was not different. The PPAV group had a long-term success rate compared with the control group (72.7% vs. 87.9%, p = .48) and an increase of left ventricular ejection fraction from 43% to 49% after successful PVC ablation at follow-up (p < .001). Echocardiography showed no significant change in valve regurgitation after ablation. No new atrioventricular block occurred. CONCLUSION: PVCs arising from PPAV regions can be successfully ablated in patients with prior AVR, without damaging the prosthetic aortic valve and atrioventricular conduction.

Stellate ganglion block and cardiac sympathetic denervation in patients with inappropriate sinus tachycardia.

BACKGROUND: Inappropriate sinus tachycardia (IST) remains a clinical challenge because patients often are highly symptomatic and not responsive to medical therapy. OBJECTIVE: To study the safety and efficacy of stellate ganglion (SG) block and cardiac sympathetic denervation (CSD) in patients with IST. METHODS: Twelve consecutive patients who had drug-refractory IST (10 women) were studied. According to a prospectively initiated protocol, five patients underwent an electrophysiologic study before and after SG block (electrophysiology study group). The subsequent seven patients had ambulatory Holter monitoring before and after SG block (ambulatory group). All patients underwent SG block on the right side first, and then on the left side. Selected patients who had heart rate reduction ≥15 beats per minute (bpm) were recommended to consider CSD. RESULTS: The mean (SD) baseline heart rate (HR) was 106 (21) bpm. The HR significantly decreased to 93 (20) bpm (P = .02) at 10 minutes after right SG block and remained significantly slower at 97(19) bpm at 60 minutes. Left SG block reduced HR from 99 (21) to 87(16) bpm (P = .02) at 60 minutes. SG block had no significant effect on blood pressure or HR response to isoproterenol or exercise (all P > .05). Five patients underwent right (n = 4) or bilateral (n = 1) CSD. The clinical outcomes were heterogeneous: one patient had complete and two had partial symptomatic relief, and two did not have improvement. CONCLUSION: SG blockade modestly reduces resting HR but has no significant effect on HR during exercise. Permanent CSD may have a modest role in alleviating symptoms in selected patients with IST.

Effective Use of Percutaneous Stellate Ganglion Blockade in Patients With Electrical Storm.

BACKGROUND: Percutaneous stellate ganglion blockade (SGB) has been used for drug-refractory electrical storm due to ventricular arrhythmia (VA); however, the effects and long-term outcomes have not been well studied. METHODS: This study included 30 consecutive patients who had drug-refractory electrical storm and underwent percutaneous SGB between October 1, 2013, and March 31, 2018. Bupivacaine, alone or combined with lidocaine, was injected into the neck with good local anesthetic spread in the vicinity of the left stellate ganglion (n=15) or both stellate ganglia (n=15). Data were collected for patient clinical characteristics, immediate and long-term outcomes, and procedure-related complications. RESULTS: Clinical characteristics included age, 58±14 years; men, 73.3%; and left ventricular ejection fraction, 34±16%. At 24 hours, 60% of patients were free of VA. Patients whose VA was controlled had a lower hospital mortality rate than patients whose VA continued (5.6% versus 50.0%; P=0.009). Implantable cardioverter-defibrillator interrogation showed a significant 92% reduction in VA episodes from 26±41 to 2±4 in the 72 hours after SGB (P<0.001). Patients who died during the same hospitalization (n=7) were more likely to have ischemic cardiomyopathy (100% versus 43.5%; P=0.03) and recurrent VA within 24 hours (85.7% versus 26.1%; P=0.009). There were no procedure-related major complications. CONCLUSIONS: SGB effectively attenuated electrical storm in more than half of patients without procedure-related complications. Percutaneous SGB may be considered for stabilizing ventricular rhythm in patients for whom other therapies have failed.

Age and Sex Estimation Using Artificial Intelligence From Standard 12-Lead ECGs.

BACKGROUND: Sex and age have long been known to affect the ECG. Several biologic variables and anatomic factors may contribute to sex and age-related differences on the ECG. We hypothesized that a convolutional neural network (CNN) could be trained through a process called deep learning to predict a person's age and self-reported sex using only 12-lead ECG signals. We further hypothesized that discrepancies between CNN-predicted age and chronological age may serve as a physiological measure of health. METHODS: We trained CNNs using 10-second samples of 12-lead ECG signals from 499 727 patients to predict sex and age. The networks were tested on a separate cohort of 275 056 patients. Subsequently, 100 randomly selected patients with multiple ECGs over the course of decades were identified to assess within-individual accuracy of CNN age estimation. RESULTS: Of 275 056 patients tested, 52% were males and mean age was 58.6±16.2 years. For sex classification, the model obtained 90.4% classification accuracy with an area under the curve of 0.97 in the independent test data. Age was estimated as a continuous variable with an average error of 6.9±5.6 years (R-squared =0.7). Among 100 patients with multiple ECGs over the course of at least 2 decades of life, most patients (51%) had an average error between real age and CNN-predicted age of <7 years. Major factors seen among patients with a CNN-predicted age that exceeded chronologic age by >7 years included: low ejection fraction, hypertension, and coronary disease (P<0.01). In the 27% of patients where correlation was >0.8 between CNN-predicted and chronologic age, no incident events occurred over follow-up (33±12 years). CONCLUSIONS: Applying artificial intelligence to the ECG allows prediction of patient sex and estimation of age. The ability of an artificial intelligence algorithm to determine physiological age, with further validation, may serve as a measure of overall health.

Outcome of combined cryo- and radiofrequency-catheter ablation in patients with supraventricular tachycardias.

BACKGROUND: There are few data regarding the outcome of a combined cryo- and radiofrequency (RF)-catheter ablation of various types of supraventricular tachycardias (SVTs) originating from near the normal conduction system. METHODS: We analyzed all patients undergoing combined cryo- and RF- catheter ablation at Mayo Clinic, Rochester, MN as part of the ablation of SVTs with potential risks of injury to the normal conduction system. This study aimed to assess the outcome of a combined cryo- and RF-catheter ablation of various types of SVTs. RESULTS: The study population consisted of 54 patients (38 ± 17 years, 32 men). A combined cryo- and RF-catheter ablation was attempted for septal accessary pathways (APs) in 26, atrioventricular nodal reentrant tachycardia (AVNRT) in 14, atrial tachycardia (AT) in 7, and junctional ectopic tachycardia in 7 patients. Forty-one patients (76%) were successfully ablated with cryoablation, and RF ablation after an unsuccessful cryoablation ablated the SVTs successfully at the same location in 6 patients (11%). Complication occurred in 1 patient (deep vein thrombosis). The cumulative freedom from SVT rate at 30 days after the procedure was 78% and there was no significant difference in the recurrence rate among the SVTs. CONCLUSION: A combined cryo- and RF-catheter ablation is clinically effective in patients undergoing SVT ablation with the potential risk of injury to the normal conduction system.

Electrophysiologic effects and outcomes of sympatholysis in patients with recurrent ventricular arrhythmia and structural heart disease.

INTRODUCTION: Autonomic modulation has been used as a therapy to control recurrent ventricular arrhythmia (VA). This study was to explore stellate ganglion block (SGB) effect on cardiac electrophysiologic properties and evaluate the long-term outcome of cardiac sympathetic denervation (CSD) for patients with recurrent VA and structural heart disease (SHD). MATERIALS AND METHODS: Patients who had recurrent VA due to SHD were enrolled prospectively. Electrophysiologic study and ventricular tachycardia (VT) induction were performed before and after left and right SGB. VA burden and long-term outcomes were assessed for a separate patient group who underwent left or bilateral CSD for drug-refractory VA due to SHD. RESULTS: Electrophysiologic study of nine patients showed that baseline mean (SD) corrected sinus node recovery time (cSNRT) increased from 320.4 (73.3) ms to 402.9 (114.2) ms after left and 482.4 (95.7) ms after bilateral SGB (P = .03). SGB did not significantly change P-R, QRS, and Q-T intervals and ventricular effective refractory period, nor did the inducibility of VA. Nineteen patients underwent left (n = 14) or bilateral (n = 5) CSD. CSD reduced VA burden and appropriate ICD therapies from a median (interquartile range) of 2.5 (0.4-11.6) episodes weekly to 0.1 (0.0-2.4) episodes weekly at 6-month follow-up (P = .002). Three-year freedom from orthotopic heart transplant (OHT) and death was 52.6%. New York Heart Association functional class III/IV and VT rate less than 160 beats per minute were predictors of recurrent VA, OHT, and death. CONCLUSION: SGB increased cSNRT without changing heart rate. CSD was more beneficial for patients with mild-to-moderate heart failure and faster VA.

Screening for cardiac contractile dysfunction using an artificial intelligence-enabled electrocardiogram.

Asymptomatic left ventricular dysfunction (ALVD) is present in 3-6% of the general population, is associated with reduced quality of life and longevity, and is treatable when found1-4. An inexpensive, noninvasive screening tool for ALVD in the doctor's office is not available. We tested the hypothesis that application of artificial intelligence (AI) to the electrocardiogram (ECG), a routine method of measuring the heart's electrical activity, could identify ALVD. Using paired 12-lead ECG and echocardiogram data, including the left ventricular ejection fraction (a measure of contractile function), from 44,959 patients at the Mayo Clinic, we trained a convolutional neural network to identify patients with ventricular dysfunction, defined as ejection fraction ≤35%, using the ECG data alone. When tested on an independent set of 52,870 patients, the network model yielded values for the area under the curve, sensitivity, specificity, and accuracy of 0.93, 86.3%, 85.7%, and 85.7%, respectively. In patients without ventricular dysfunction, those with a positive AI screen were at 4 times the risk (hazard ratio, 4.1; 95% confidence interval, 3.3 to 5.0) of developing future ventricular dysfunction compared with those with a negative screen. Application of AI to the ECG-a ubiquitous, low-cost test-permits the ECG to serve as a powerful screening tool in asymptomatic individuals to identify ALVD.

Feasibility and safety of percutaneous epicardial access for mapping and ablation for ventricular arrhythmias in patients on oral anticoagulants.

PURPOSE: This study aimed to assess the risk of procedure-related complications of percutaneous epicardial access (EpiAcc) for radiofrequency catheter ablation (RFA) of ventricular arrhythmias (VAs) in patients chronically treated oral anticoagulants (OACs) with warfarin compared to those not on OACs. METHODS: We analyzed 205 patients (53 ± 16 years, 155 males) undergoing percutaneous EpiAcc as part of an RFA for VAs, and compared the outcome between patients chronically on OACs with warfarin (OAC group) and those without (non-OAC group). RESULTS: Forty-seven patients (23%) were chronically treated on OACs before their procedure. EpiAcc in patients on OAC (OAC group) was not associated with an increased risk of cardiac tamponade (11% vs. 6%, p = 0.238) compared to non-OAC group, but a higher risk of need for blood transfusion (17% vs. 6%; p = 0.013). With respect to the OAC group, the international normalized ratio (INR) on the day of the RFA was ≥ 2.0 in 9 patients (19%) and < 2.0 in the remaining 38 patients (81%). The rate of all complication and blood transfusion were similar between them (11% vs. 21%; p = 0.496, 11% vs. 18%; p = 0.600). CONCLUSION: Percutaneous EpiAcc in patients on chronic OAC with warfarin did not significantly increase the risk of cardiac tamponade, but was associated with a higher risk of need for blood transfusion. EpiACC in patients with an INR > 2.0 is reasonable in experienced hands when clinical indications are strong.

Safety and Efficacy of Cryoablation in Patients With Ventricular Arrhythmias Originating From the Para-Hisian Region.

OBJECTIVES: This study aimed to assess the outcome of cryoablation in patients with ventricular arrhythmias (VAs) originating from the para-Hisian region. BACKGROUND: There are few data regarding the outcome of cryoablation in patients with VAs originating from the para-Hisian region, where there is the risk of injury to the conduction system. METHODS: The study analyzed all patients undergoing cryoablation at the Mayo Clinic (Rochester, Minnesota) as part of an ablation for VAs originating from the para-Hisian region. RESULTS: The study population consisted of 10 patients (64 ± 15 years of age, 7 men). Cryoenergy was applied after an unsuccessful radiofrequency (RF) ablation in 8 (80%) patients. The VAs were successfully ablated with cryoablation in 7 (70%) patients; RF ablation after an unsuccessful cryoablation eliminated the VAs at almost the same location with careful monitoring in 1 patient. The authors could not ablate the actual focus because a transient atrioventricular block developed during cryo- and RF energy applications, which led to an unsuccessful ablation in the remaining 2 patients. A complete atrioventricular block occurred during the cryoenergy application in 1 patient, who needed a permanent pacemaker implantation. There were no VA recurrences in 4 of 8 (50%) patients with procedural success during a median follow-up period of 122 days (interquartile range: 43 to 574 days). CONCLUSIONS: Cryoablation is clinically effective in some patients with VAs originating from the para-Hisian region, where there is the risk of injury to the conduction system, and therefore should be considered as an alternative to or in addition to RF ablation in these cases. Cryoablation requires care because it can also lead to major complications.

Fragmentation of QRS complex during ventricular pacing is associated with ventricular arrhythmic events in patients with left ventricular dysfunction.

BACKGROUND: QRS fragmentation (fQRS) during baseline ventricular conduction, a myocardial fibrosis marker, is associated with increased risk of ventricular tachyarrhythmias but may not manifest unless ventricular activation change is provoked. We examined the association of fQRS during right ventricular (RV) pacing with death and ventricular tachyarrhythmia in patients with left ventricular (LV) dysfunction undergoing electrophysiology study (EPS). METHODS AND RESULTS: Study participants had LV dysfunction (ejection fraction < 50%) undergoing EPS from January 2002 to May 2014 at Mayo Clinic in Rochester, Minnesota. fQRS during RV stimulation involved >2 notches on R/S waves identified in ≥2 contiguous standard electrocardiographic leads representing anterior, inferior, or lateral ventricular segments. Primary outcomes were ventricular tachyarrhythmias that were symptomatic or required intervention and total and cardiac deaths. In all, 528 patients participated (mean age, 65 years; male sex, 80%). Of them, 312 (59%) had ischemic cardiomyopathy and mean (SD) left ventricular ejection fraction (LVEF) of 33.2% (9.5%); 457 (87%) had implantable cardiac devices (implanted defibrillator, n  =  380). Mean (SD) follow-up was 3.2 (3.0) years. fQRS during RV pacing was observed in 292 patients (60%) in any ventricular segment. Patients with fQRS during RV pacing had 2.5 higher rate of ventricular tachyarrhythmia events than patients with no fQRS (hazard ratio [95% CI], 2.45 [1.5-4.2]; P < 0.01), after correcting for baseline ventricular conduction defect and QRS duration, LVEF, inducible sustained ventricular tachycardia, diabetes mellitus, chronic kidney disease, and ischemic cardiomyopathy. CONCLUSIONS: RV stimulation can unmask fQRS, and it is associated with increased risk of ventricular tachyarrhythmia in LV dysfunction.

Feasibility of Performing Radiofrequency Catheter Ablation and Endomyocardial Biopsy in the Same Setting.

In patients with unexplained cardiomyopathy, electroanatomical mapping can identify abnormal tissue to target during electrophysiology-guided endomyocardial biopsy (EP-guided EMB). The objective of this study is to determine whether catheter ablation performed in the same setting as EP-guided EMB increases procedural risk. Sixty-seven patients (mean age 54.4 ± 13.8, 57% male) undergoing EP-guided EMB were included. Radiofrequency catheter ablation was performed in 17 patients (25%) for ventricular arrhythmias and in 2 (3%) for typical atrial flutter. Femoral arterial access was obtained in 90% ablation patients and 40% biopsy-only patients; vascular access complications were more common in the ablation group than in the EMB-only group (p = 0.02). There were no significant differences in rate of tricuspid regurgitation, thromboembolism, or pericardial effusion, whether procedural anticoagulation was used. In conclusion, catheter ablation and procedural anticoagulation can be combined with EP-guided EMB with an increased risk of vascular access complications, but no significant increase in intracardiac complications.

Impact of sedation vs. general anaesthesia on percutaneous epicardial access safety and procedural outcomes.

Aims: Patient movement while under moderate/deep sedation may complicate percutaneous epicardial access (EpiAcc), mapping and ablation. We sought to compare procedural outcomes in patients undergoing EpiAcc under sedation vs. general anaesthesia (GA) for ablation. Methods and results: Patients undergoing EpiAcc between January 2004 and July 2014 were included. Safety, procedural, and clinical outcomes were compared between patients undergoing EpiAcc under sedation or GA for ventricular tachycardia or premature ventricular complex ablation. Between January 2004 and July 2014, 170 patients underwent EpiAcc (mean age, 53.2 ± 15.8 years; average ejection fraction, 44.3 ± 15.3%). The majority (122 [72%] patients) were male. GA was used in 69 (40.6%). There was no difference in route of access (more often anterior, 53.0%) or the rate of successful access (96% overall) between groups. Similarly, the site of ablation (endocardial vs. epicardial vs. combined endocardial/epicardial) was similar between groups. Complications were equally seen between groups-the most frequent event/complication was pericardial effusion, occurring in 10.6% of patients. Finally, procedural and clinical success rates between GA and sedation groups were comparable (93 vs. 91% and 44 vs. 51%, respectively, P > 0.05). Conclusions: Choice of anaesthesia for EpiAcc does not appear to significantly affect safety and procedural or clinical outcomes. For patients in whom anaesthesia may pose increased risk, it is reasonable to obtain epicardial access under sedation.