Continued epicardial conduction after endocardial posterolateral mitral annular linear ablation for perimitral flutter revealed with high-density Rhythmia mapping

Unusual dual-loop reentry during cavo-tricuspid isthmus–dependent atrial flutter

Persistent atrial fibrillation: should we always ice the back of the left atrium?

Sex effect on efficacy of pulmonary vein cryoablation in patients with atrial fibrillation: data from the multicenter real-world 1STOP project Abstract Purpose Pulmonary vein isolation (PVI) using cryoablation (PVI-C) is a widespread therapy for treating symptomatic, recurrent atrial fibrillation (AF). The impacts of sex on efficacy and safety of PVI-C in a real-world clinical practice is lacking. In a multicenter prospective project, we evaluated whether clinical characteristics, procedure parameters, procedural complications, long-term AF recurrence rates, and/or AF-related symptoms differed according to sex in patients treated with PVI-C. Methods Data from the study population were collected in the framework of the 1STOP ClinicalService® project, involving 47 Italian cardiology centers. Multivariable statistical analyses were conducted to determine if any baseline clinical characteristics impacted the efficacy of PVI-C. Results From April 2012, 2125 patients (27% female, 59 ± 11 years, 73% paroxysmal AF, and mean left atrial diameter = 42 ± 8 mm) underwent PVI-C. According to baseline characteristics, women were more likely to be older, with higher clinical risk scores (e.g., CHA2DS2-VASc), and a higher number of tested antiarrhythmic drugs before the index PVI-C procedure. Male and female cohorts showed comparable procedure time (mean = 107.7 ± 46.8 min) and a similar incidence of periprocedural complications (4.5% overall), even after adjustment for baseline characteristics (P = 0.880). The multivariable analyses demonstrated that the strongest predictor of AF recurrences was sex (0.74; 95% CI 0.58–0.93; P = 0.011). After propensity score adjustment, the hazard ratio from a multivariable model, which included age and AF type (persistent) as covariates, was 0.76 (0.60–0.97) (P = 0.025). Conclusions According to the 1STOP project, in a real-world setting, PVI-C was relatively safe regardless of the patient’s sex; however, when considering efficacy of the procedure, female patients had a lower long-term efficacy in comparison to males. Clinical trial registration NCT01007474

Single- and dual-site ventricular pacing entirely through the coronary sinus for patients with prior tricuspid valve surgery Abstract Purpose Transvenous right ventricular pacing has traditionally been avoided after surgical tricuspid valve repair or replacement because of possible valvular dysfunction. Epicardial pacing has been used but it requires surgical thoracotomy and has higher lead failure rates when compared to transvenous pacing. We evaluated the lead stability and clinical outcomes in patients with isolated coronary sinus (CS) lead due to relative contraindication to transvenous pacing from prior tricuspid valve (TV) surgery. Methods We retrospectively examined a single-center cohort of 34 patients with TV disease and/or surgery who underwent permanent pacemaker implantation with a left ventricular CS lead as the only ventricular pacing lead (to avoid crossing the TV). The clinical outcome, echocardiographic data, and pacing thresholds were evaluated at follow-up. Results We implanted 19 patients with a single-CS lead and 15 patients with dual-CS leads. The average left ventricular ejection fraction was 56 ± 13% prior to lead implantation and remained stable at 2-year follow-up. The tricuspid regurgitation remained mild at follow-up. The average lead pacing threshold was 1.2 ± 0.6 V × ms at implant and 1.1 ± 0.4 V × ms at 2-year follow-up (P = 0.39). For patients with dual-CS leads, the pacing threshold was 1.2 ± 0.7 V × ms at implant and 1.1 ± 0.5 V × ms at 2-year follow-up (P = 0.52). Conclusions The use of ventricular pacing entirely through the CS is an effective and minimally invasive method that provides stable pacing for patients with prior TV surgery in whom transvenous lead placement either is not possible or is relatively contraindicated.

Multisite pacing via a quadripolar lead for cardiac resynchronization therapy Abstract Cardiac resynchronization therapy is challenging. Up to 40% of patients are non-responder. Multisite pacing via a quadripolar lead, also called multipoint/multipole pacing (MPP), is a debated alternative. In this review, we summarize evidence in the literature, tips and pitfalls related to MPP programming, and the different algorithms of MPP in different manufacturers.

A subvalvular catheter approach for radiofrequency ablation of right-sided accessory pathways Abstract Background Conventional catheter ablation of right-sided accessory pathways (RAPs) can be challenging. Objective To determine if a subvalvular catheter approach for RAPs targeting the ventricular insertion site, as on the left side, can improve catheter stability and tissue contact and thus increase acute and chronic ablation success rates. Methods and results We retrospectively compared 22 patients (pts) with conventional catheter ablation of RAPs (group 1) with 9 consecutive pts (group 2) undergoing catheter ablation of a RAP using a subvalvular catheter approach targeting the ventricular site of AP. Ablation failed in 2/22 group 1 vs 0/9 group 2 pts (ns) and recurrences of AP conduction were registered in 4/19 group 1 vs 1/9 group 2 pts (ns) during follow-up. Significant shorter values were found in group 2 pts compared with group 1 for number of RF applications (3.6 ± 1.6 vs 8.2 ± 4.3), AP block time (6.2 ± 2.4 vs 9.2 ± 3.9 min), fluoroscopy time (17.2 ± 6.9 vs 25.6 ± 10.3 min), and procedure time (70.8 ± 23.9 vs 138 ± 44.4 min). There were no procedure related complications. Conclusion Catheter ablation of RAPs using a subvalvular approach seems as effective and safe compared with conventional ablation but with reduced procedure time and radiation exposure and might be at least considered an alternative after failed conventional catheter ablation of RAPs.

Incidence and predictors of pacemaker-induced cardiomyopathy with comparison between apical and non-apical right ventricular pacing sites Abstract Background Asynchronous activation of left ventricle (LV) due to chronic right ventricular (RV) pacing has been known to predispose to LV dysfunction. The predictors of LV dysfunction remain to be prospectively studied. This study was designed to follow up patients with RV pacing to look for development of pacing-induced cardiomyopathy (PiCMP), identify its predictors and draw comparison between apical vs non-apical RV pacing sites. Methods Three hundred sixty-three patients undergoing dual-chamber and single-chamber ventricular implants were enrolled and followed up. Baseline clinical parameters; paced QRS duration and axis; RV lead position by fluoroscopy; LV ejection fraction (LVEF) by Simpson’s method on transthoracic echocardiography (TTE); intraventricular dyssynchrony (septal-posterior wall contraction delay) and interventricular dyssynchrony (aortopulmonary ejection delay) on TTE were recorded. The patients were followed up at 6–12 monthly interval with estimation of LVEF and pacemaker interrogation at each visit. Pacemaker-induced cardiomyopathy (PiCMP) was defined as a fall in ejection fraction of 10% as compared to the baseline LVEF. Patients developing PiCMP were compared to other patients to identify predictors. Results The mean age of study population was 59.8 years, 68.3% being males. Fifty-one percent and 49% patients underwent VVIR and DDDR pacemaker implantation, respectively. After attrition, 254 patients were analysed. PiCMP developed in 35 patients (13.8%) over a mean follow-up of 14.5 months. After multivariate analysis, burden of ventricular pacing > 60% [HR 4.26, p = 0.004] and interventricular dyssynchrony (aortopulmonary ejection delay > 40 msec) [HR 3.15, p = 0.002] were identified as predictors for PiCMP in patients undergoing chronic RV pacing. There was no effect of RV pacing site (apical vs non-apical) on incidence of PiCMP [HR 1.44, p = 0.353). Conclusions Incidence of PiCMP with RV pacing was found to be 13.8% over a mean follow-up of 14.5 months. Burden of right ventricular pacing and interventricular dyssynchrony were identified as the most important predictors for the development of PiCMP. Non-apical RV pacing site did not offer any benefit in terms of incidence of PiCMP over apical lead position.

CHA 2 DS 2 -VASc score predicts 30-day readmission due to thromboembolic complications following cardioversion of atrial fibrillation: insights from US National Readmissions Database Abstract Purpose Determine whether the CHA2DS2-VASc score predicts rates of hospitalization associated with thromboembolic complications (TEC) in the 30, 60, and 90 days following cardioversion (CV) for atrial fibrillation (AF). Methods The 2014 National Readmissions Database was analyzed to identify readmissions following the index hospitalization for AF and CV. A CHA2DS2-VASc score was calculated for each patient from diagnosis codes associated with the index admission. The primary outcome was the incidence of readmission due to TEC in the 30, 60, and 90 days after CV stratified by CHA2DS2-VASc scores ≤ 1, 2–3, and ≥ 4; the secondary outcome was specific clinical risk factors independently associated with TEC within 30 days of CV. Results A total of 109,420 weighted index admissions for AF and CV were identified in between January 1, 2014, and November 30, 2014. Of these, 16,535 (15.1%) had a CHA2DS2-VASc score of 0–1, 39,544 (36.1%) had a score of 2–3, and 53,340 (48.8%) had a score of ≥ 4. Readmission due to TEC occurred in 48 (0.29%), 167 (0.42%), and 394 (0.74%) patients with CHA2DS2-VASc scores ≤ 1, 2–3, and ≥ 4, respectively, in the 90-day period after CV. The only significant predictor for 30-day TEC-associated readmission after CV was age > 65 years old. Conclusions This study demonstrated the utility of CHA2DS2-VASc score in predicting TEC-associated readmission rate following CV and the temporal relationship of TEC to CV. Patients > 65 years old without other comorbidities may benefit from 30-day OAC following successful CV irrespective of the duration of AF episodes.

Prognostic implications of QRS dispersion for major adverse cardiovascular events in asymptomatic women and men: the Multi-Ethnic Study of Atherosclerosis Abstract Background QRS dispersion measured as the difference between maximal and minimal QRS duration in the standard 12-lead electrocardiogram has been shown to be associated with increased mortality in heart failure (HF) patients and increased arrhythmic events in patients with cardiomyopathy. Aims This study sought to examine the prognostic association between baseline QRS dispersion and future cardiovascular events in individuals without known prior cardiovascular disease. Methods The association of QRS dispersion with cardiovascular events was examined in 6510 MESA (Multi-Ethnic Study of Atherosclerosis) participants. Participants with bundle branch block were excluded. Study participants were divided into two groups based on the 95th percentile of QRS dispersion (QRS dispersion < 34 ms [group I] and QRS dispersion ≥ 34 ms [group II]). Cox proportional hazard models adjusting for demographic and clinical risk factors were used to examine the association of QRS dispersion with incident cardiovascular events (major adverse cardiovascular events [MACE]) and mortality. Analysis was repeated by forcing Framingham risk factors. Results Mean age was 62 ± 10 years in group I and 63 ± 10 years in group II (P = 0.02). QRS dispersion ≥ 34 ms was associated significantly with MACE (HR 1.30; 95% CI 1.04–1.62) and mortality (HR 1.33; 95% CI 1.03–1.73) after adjustment for cardiovascular risk factors and potential cofounders. Similar results were seen for mortality after adjustment for Framingham risk factors. Conclusion QRS dispersion ≥ 34 ms predicts cardiovascular events and mortality.