Search

Introduction: Luminal esophageal temperature (LET) monitoring during atrial fibrillation (AF) ablation is widely used to reduce the incidence of endoscopically detected esophageal lesion (EDEL). We sought to assess whether specific patterns of LET variation are associated with EDEL. Methods: A high‐fidelity multisensor probe was used to record LET in AF patients undergoing radiofrequency ablation (RFA) or cryoballoon ablation (CBA). Explainable machine learning and SHapley Additive exPlanations (SHAP) analysis were used to predict EDEL and assess feature importance. Results: A total of 94 patients (38.3% persistent AF, 71.3% male, 72 RFA, and 22 CBA) were included. EDEL was detected in 11 patients (10 RFA and one CBA). In the RFA group, the highest LET recorded was similar between patients with and without EDEL (40.6 [40.1–41]°C vs. 40.2 [39.1–40.9]°C; p =.313), however, the rate of LET rise for the highest recorded peak was higher (0.08 [0.03–0.12]°C/s vs. 0.02 [0.01–0.05]°C/s; p =.033), and the area under the curve (AUC) for the highest peak was smaller (412.5 [206.8–634.1] vs. 588.6 [380.4–861.1]; p =.047) in patients who had EDEL. In case of CBA, the patient with EDEL had a faster LET decline (0.12 vs. 0.07 [0.02–0.14]°C/s), and a smaller AUC for the lowest trough (2491.3 vs. 2629.3 [1712.6–5283.2]). SHAP analysis revealed that a rate of LET change higher than 0.05°C/s and an AUC less than 600 were more predictive of EDEL in RFA. Conclusion: The rate of LET change and AUC for the recorded temperature predicted EDEL, whereas absolute peak temperatures did not. [ABSTRACT FROM AUTHOR]

Introduction: Variants of cardiomyopathy genes in patients with nonischemic cardiomyopathy (NICM) generate various phenotypes of cardiac scar and delayed enhancement cardiac magnetic resonance (DE‐CMR) imaging which may impact ventricular tachycardia (VT) management. Methods: The objective was to compare the findings of cardiomyopathy genetic testing on DE‐CMR imaging and long‐term outcomes among patients with NICM undergoing VT ablation procedures. Image phenotyping and genotyping were performed in a consecutive series of patients referred for VT ablation and correlated to survival free of VT. Scar depth index (SDI) (% of scar at 0‐3 mm, 3‐5 mm and >5 mm projected on the closest endocardial surface) was determined. Results: Forty‐three patients were included (11 women, 55 ± 14 years, ejection fraction (EF) 45 ± 16%) and were followed for 3.4 ± 2.9 years. Pathogenic variants (PV) were identified in 16 patients (37%) in the following genes: LMNA (n = 5), TTN (n = 5), DSP (n = 2), AMLS1 (n = 1), MYBPC3 (n = 1), PLN (n = 1), and SCN5A (n = 1). A ring‐like septal scar (RLSS) pattern was more often seen in patients with pathogenic variants (66% vs 15%, p =.001). RLSS was associated with deeper seated scars (SDI >5 mm 30.6 ± 22.6% vs 12.4 ± 16.2%, p =.005), and increased VT recurrence (HR 5.7 95% CI[1.8‐18.4], p =.003). After adjustment for age, sex, EF, and total scar burden, the presence of a PV remained independently associated with worse outcomes (HR 4.7 95% CI[1.22‐18.0], p =.02). Conclusions: Preprocedural genotyping and scar phenotyping is beneficial to identify patients with a favorable procedural outcome. Some PVs are associated with an intramural, deeper seated scar phenotype and have an increase of VT recurrence after ablation. [ABSTRACT FROM AUTHOR]

Background/Objectives: The QDOT‐MICRO™ catheter allows very high‐power and short‐duration (vHPSD) ablation. This study aimed to investigate lesion characteristics using different ablation settings. Methods: Radiofrequency applications (90 W/4 s, temperature‐control mode with 55°C or 60°C target) were performed in excised porcine myocardium using three different approaches: single (SA), double nonrepetitive (DNRA), and double repetitive applications (DRA). Applications were performed with an interval of 1 min for DNRA, and without interval for DRA. Results: A total of 480 lesions were analyzed. Lesion depth and volume were largest for DRA followed by DNRA and SA regardless of catheter direction (depth: 3.8 vs. 3.3 vs. 2.6 mm, p <.001 for all comparisons; volume: 176.6 vs. 145.1 vs. 97.0 mm3, p <.001 for all comparisons). Surface area was significantly larger for DRA than for SA (45.1 vs. 38.3 mm2, p <.001) and larger for DNRA than for SA (44.5 vs. 38.3 mm2, p <.001), but was similar between DRA and DNRA (45.1 vs. 44.5 mm2, p =.54). Steam‐pops more frequently occurred for DRA than for SA (15.6% vs. 4.4%, p =.004) and DNRA (15.6% vs. 6.9%, p =.061), but the incidence was similar between SA and DNRA (4.4% vs. 6.9%, p = 1). Although surface area and lesion volume were larger in lesions with steam‐pops than without steam‐pops (46.5 vs. 38.1 mm2, p =.018 and 128.3 vs. 96.8 mm3, p =.068, respectively), lesions were not deeper (pop(+): 2.5 mm vs. pop(−): 2.6 mm, p =.75). Conclusions: DNRA produces larger lesions than SA without increasing the risk of steam‐pops. DRA produces the largest lesions among the three groups, but with an increased risk of steam‐pops. Even with steam‐pops, lesions do not become deeper in vHPSD ablation. [ABSTRACT FROM AUTHOR]

Predict the Impact of PVC on Myocardial Function Introduction Reversible premature ventricular complexes-induced cardiomyopathy (PVC-CMP) is a well-described, multi-factorial entity. Single predictors, such as PVC burden or QRS duration, may not apply equally to all patients in contemporary unselected populations including patients with structural heart disease (SHD) or with particular origin such as epicardial (EPI) PVC. We sought to evaluate clinical criteria associated with PVC-CMP notably focusing on the EPI origin impact and ECG recognition and the value of a new composite predictor of PVC-CMP, the PVC-CMP-Index. Methods and Results We studied 107 consecutive patients (69 men; mean age = 56 ± 16 years) with frequent PVC (23.1 ± 11.5%) referred for PVC ablation. Thirty-six patients (33.6%) had an underlying SHD and 25 patients (23.4%) an EPI PVC origin. After a mean follow-up of 22.7 ± 15.3 months, 72.9% achieved a long-term successful ablation and 54.2% had PVC-CMP. PVC-CMP prevalence was significantly higher in patients with an EPI compared to endocardial PVC focus (84.0% vs. 45.1%, respectively, P < 0.001). EPI PVC origin (OR = 68.7 IC95% [3.5-1363], P = 0.005), as well as SHD (OR = 12.3 IC95% [1.6-92.6], P = 0.015), was independent predictor of PVC-CMP. While PVC burden (AUC = 0.78) or PVC-QRS width (AUC = 0.68) independently predicted PVC-CMP, the PVC-CMP-Index (values ≥39) defined as: PVC burden (0-1) × PVC-QRS width (milliseconds) × a constant C (1.28 for SHD or 2 for ECG suggesting EPI origin based on our ECG 3-step algorithm), highly correlated with PVC-CMP (AUC = 0.91, sensitivity = 93%, specificity = 80%). Conclusion We developed a new index, which incorporates PVC burden, QRS width, and presence of SHD or suspected EPI origin that best predicted PVC-CMP. [ABSTRACT FROM AUTHOR]

Ventricular Tachycardia and Atrioventricular Block Introduction In pediatric patients with pacemakers implanted for atrioventricular block (AVB), nonsustained ventricular tachycardia (NSVT) detected during routine surveillance is a finding of unknown significance. We sought to describe the incidence of NSVT and determine if there was an association between NSVT and adverse outcomes in these patients. Methods and Results This is a single-center retrospective study of 136 patients (1971-2013) with pacemakers implanted for advanced and complete AVB. Exclusion criteria: structural heart disease, diagnoses of myocarditis, cardiomyopathy or channelopathy preceding AVB diagnosis, and sustained or polymorphic ventricular tachycardia (VT) as the first occurring arrhythmia after pacemaker implant. During median follow-up of 11.6 years (IQR 4.3 years, 17 years), 14 (10%) patients had NSVT. There were 6 (4.4%) deaths. Overall, Kaplan-Meier 20-year survival from time of implant was 93%. By univariate analysis, earlier mortality was associated with NSVT (P = 0.010), sustained left ventricular (LV) dysfunction (P = 0.004), maternal autoantibodies (P = 0.017), and acquired AVB (P = 0.049). By multivariate analysis, earlier mortality was associated with NSVT (HR: 5.39 [95% CI: 1.02-28.41]; P = 0.047) and sustained LV dysfunction (HR: 10.24 [95% CI: 1.83-57.32]; P = 0.008). Conclusions In children with pacemakers implanted for AVB, NSVT is not uncommon and may be associated with increased mortality. Persistent LV dysfunction may also be a potential factor associated with death. Closer follow-up should be considered in patients with these findings. Large, multicenter studies should be considered to confirm these findings and identify risk stratification methods for this unique patient population. [ABSTRACT FROM AUTHOR]

Prognosis of QRS Axis Deviation in CRT-D Introduction QRS duration and morphology are currently recognized as recommended criteria for the selection of CRT candidates. It has recently been shown that patients with left bundle branch block (LBBB) derive substantial clinical benefit from CRT. The aim of this study is to investigate the prognostic impact of QRS axis deviation (AD) in HF patients with LBBB undergoing CRT. Methods and Results We retrospectively evaluated 707 HF patients with LBBB who underwent CRT at five centers. Baseline QRS axis was defined as normal (NA: -30° to 90°), right axis deviation (RAD: 90° to 180°) and left axis deviation (LAD: <−30°). The primary endpoint was a composite of all cause death/HF hospitalization. The risk of endpoint by AD was evaluated with both Kaplan-Meier and Cox proportional hazard analysis. Among 707 patients (73% M, median age: 71 [62,77] years), 323 (46%) had NA, 359 (51%) LAD, and 25 (3.5%) RAD. Baseline clinical characteristics were similar between the three groups. Over a mean follow-up of 32 ± 25 months, 141 deaths occurred (21%) and 36% (n = 255) met with the composite endpoint. A significantly higher proportion of RAD patients (52%) reached the endpoint (LAD 40%, NA 30%). KM analysis showed that RAD and LAD patients had worse event free survival and in multivariate analysis both LAD (HR: 1.40; 95% CI: 1.05-1.86; P = 0.021) and RAD (HR: 2.49; 95% CI: 1.31-4.74; P = 0.005) were independently associated with worse clinical outcome. Conclusions Right or left axis deviation in the presence of LBBB in HF patients undergoing CRT are independent predictors of poor prognosis. [ABSTRACT FROM AUTHOR]

Focal But Not Diffuse Fibrosis Burden Predicts CRT Remodeling Response Introduction Many heart failure patients with dyssynchrony do not reverse remodel (RR) in response to cardiac resynchronization therapy (CRT). The presence of focal and diffuse interstitial myocardial fibrosis may explain this high nonresponse rate. T1 mapping is a new cardiac magnetic resonance imaging (CMR) technique that overcomes the limitations of conventional contrast CMR and provides reliable quantitative assessment of diffuse myocardial fibrosis. The study tested the hypothesis that focal and diffuse fibrosis quantification would correlate with a lack of left ventricular (LV) RR to CRT. Methods and Results In a prospective study of 48 consecutive patients (27 ischemic cardiomyopathy, 21 dilated cardiomyopathy) LV scar burdens were quantified (scar core and gray zone using late gadolinium enhancement LGE CMR; interstitial fibrosis using T1 mapping) before CRT implant. LV RR was defined by a ≥ 15% reduction in LV end-systolic volume 6 months postimplant. Twenty-seven (56%) patients were responders with RR. Association between scar quantification and LV RR was assessed using the Poisson regression model. Univariate analysis showed that QRS duration/morphology, scar core, and gray zone volumes expressed as % of LV mass and extracellular volume index (ECV) (a measure of interstitial fibrosis from T1 mapping) to be significant predictors of LV RR. Multivariable-adjusted analyses demonstrated scar core quantification (≥13.7% LV mass) to be the only independent predictor of LV RR (prevalence ratio 0.40, P = 0.038). Conclusions Focal scar burden detected by LGE CMR is associated with a poor response to CRT. Diffuse interstitial fibrosis assessment by T1 mapping, however, is not independently predictive of CRT response. [ABSTRACT FROM AUTHOR]

Vagus Nerve Stimulation and Myocardial Ischemia-Reperfusion Injury Background Low-level vagus nerve stimulation (LL-VNS) has been demonstrated to protect myocardium against acute ischemia/reperfusion (I/R) injury. However, the underlying mechanism of this protective effect remains unknown. Objective This study aimed to test the hypothesis that LL-VNS exerts cardioprotective effect on acute I/R injury in canines via antioxidative stress and antiapoptosis reactions. Method Thirty anesthetized mongrel dogs were randomly divided into three groups: I/R group (N = 12, the left anterior descending coronary artery was occluded for 1 hour following by 1 hour reperfusion), LL-VNS group (N = 9, I/R plus LL-VNS), and sham group (N = 9, sham surgery without LL-VNS). The voltage threshold was set at 80% of the voltage required to slow the sinus rate. Infarct size was assessed with Evans Blue and triphenyltetrazolium chloride. Activity assays, TUNEL staining, and western blotting were performed to determine markers of oxidative stress and apoptosis. Results LL-VNS significantly decreased the incidence of ventricular arrhythmias, increased vagal tone, as confirmed by heart rate viability, and reduced infarct size compared with the I/R group. This improvement was associated with a reduction in myocardial neutrophil infiltration, the inhibition of oxidative stress, and the suppression in cardiomyocyte apoptosis. In contrast, the lack of LL-VNS in the I/R group induced the opposite effect compared with the sham group. Conclusion LL-VNS exerts protective effects on myocardial I/R injury. Its potential mechanisms involve the suppression of oxidative stress and cellular apoptosis. [ABSTRACT FROM AUTHOR]

Heart Rate Turbulence in Mice Introduction Recent studies have demonstrated the feasibility of measuring heart rate turbulence (HRT) as a marker of baroreflex function in healthy mice. The aim of this investigation was to measure HRT in a mouse model with induced structural heart defects and to determine if there were threshold values of HRT for inducible ventricular tachycardias (VTs). Methods and Results HRT was measured during electrophysiological investigations 2 weeks after transverse aortic constriction (TAC, n = 13) or myocardial cryoinfarction (MCI, n = 14). Sham-operated mice served as controls (n = 8 for TAC controls and n = 9 for MCI controls). Mice with heart disease lacked an early acceleration (turbulence onset [TO]) in heart rate after extrastimulus pacing (heart disease: 0.39% [0.19%-0.59%] vs. all controls: -0.04% [-0.25-0.19%]; P < 0.01). At a cutoff value of >0.25%, TO could be used to classify mice with induced heart disease with a sensitivity of 64.0% and specificity of 88.2% (P < 0.01) but did not identify mice at higher risk of induced VTs. Animals that were susceptible to VTs (n = 8) had lower values for turbulence slope (TS) compared with noninducible mice (6.2 milliseconds/beat [3.1-9.5 milliseconds/beat] vs. 10.1 milliseconds/beat [7.2-14.2 milliseconds/beat]; P = 0.03). TS <7.8 milliseconds/beat identified mice with inducible VTs with a sensitivity of 75.0% and specificity of 75.8% (P = 0.02). Conclusion Measurement of HRT is feasible in mouse models with induced structural heart disease. More abnormal values for TO were found in the presence of structural heart disease but did not predict susceptibility to VTs. Decreased TS was associated with VTs induced by programmed stimulation. [ABSTRACT FROM AUTHOR]

Efficacy of Bio-Absorbable Antibacterial Envelope Introduction Cardiac implantable electronic device (CIED) infections are potentially preventable complications associated with high morbidity, mortality, and cost. A recently developed bio-absorbable antibacterial envelope (TYRX™-A) might prevent CIED infections in high-risk subjects. However, data regarding safety and efficacy have not been published. Methods and Results In a single-center retrospective cohort study, we compared the prevalence of CIED infections among subjects with ≥2 risk factors treated with the TYRX™-A envelope (N = 135), the nonabsorbable TYRX™ envelope (N = 353), and controls who did not receive an envelope (N = 636). Infection was ascertained by individual chart review. The mean (95% confidence interval) number of risk factors was 3.08 (2.84-3.32) for TYRX™-A, 3.20 (3.07-3.34) for TYRX™, and 3.09 (2.99-3.20) for controls, P = 0.3. After a minimum 300 days follow-up, the prevalence of CIED infection was 0 (0%) for TYRX™-A, 1 (0.3%) for TYRX™, and 20 (3.1%) for controls (P = 1 for TYRX™-A vs. TYRX™, P = 0.03 for TYRX™-A vs. controls, and P = 0.002 for TYRX™ vs. controls). In a propensity score-matched cohort of 316 recipients of either envelope and 316 controls, the prevalence of infection was 0 (0%) and 9 (2.8%), respectively, P = 0.004. When limited to 122 TYRX™-A recipients and 122 propensity-matched controls, the prevalence of CIED infections was 0 (0%) and 5 (4.1%), respectively, P = 0.024. Conclusions Among high-risk subjects, the TYRX™-A bio-absorbable envelope was associated with a very low prevalence of CIED related infections that was comparable to that seen with the nonabsorbable envelope. [ABSTRACT FROM AUTHOR]

Visually Guided PV Isolation Introduction Visually guided laser balloon (VGLB) ablation is unique in that the operator delivers ablative energy under direct visual guidance. In this multicenter study, we sought to determine the feasibility, efficacy, and safety of performing pulmonary vein isolation (PVI) using this VGLB. Methods Patients with symptomatic, drug-refractory paroxysmal atrial fibrillation (AF) underwent PVI using the VGLB with the majority of operators conducting their first-ever clinical VGLB cases. The primary effectiveness endpoint was defined as freedom from treatment failure that included: Occurrence of symptomatic AF episodes ≥1 minutes beyond the 90-day blanking, the inability to isolate 1 superior and 2 total PVs, occurrence of left atrial flutter or atrial tachycardia, or left atrial ablation/surgery during follow-up. Results A total of 86 patients (mean age 56 ± 10 years, 67% male) were treated with the VGLB at 10 US centers. Mean fluoroscopy, ablation, and procedure times were 39.8 ± 24.3 minutes, 205.2 ± 61.7 minutes, and 253.5 ± 71.3 minutes, respectively. Acute PVI was achieved in 314/323 (97.2%) of targeted PVs. Of 84 patients completing follow-up, the primary effectiveness endpoint was achieved in 50 (60%) patients. Freedom from symptomatic or asymptomatic AF was 61%. The primary adverse event rate was 16.3% (8.1% pericarditis, phrenic nerve injury 5.8%, and cardiac tamponade 3.5%). There were no cerebrovascular events, atrioesophageal fistulas, or significant PV stenosis. Conclusions This multicenter study of operators in the early stage of the learning curve demonstrates that PVI can be achieved with the VGLB with a reasonable safety profile and an efficacy similar to radiofrequency ablation. [ABSTRACT FROM AUTHOR]

Why Is Left Atrial Appendage Morphology Related to Strokes? Background A specific morphology of left atrial appendage (LAA) has been reported to be related to stroke in nonvalvular atrial fibrillation (AF) patients. However, the mechanism is not completely understood. This study evaluated whether a specific LAA morphology was related to stroke, and whether it was related to the change of flow velocity and size of LAA in AF patients. Methods The morphology, size, and flow velocity of LAA were evaluated in AF patients with ischemic strokes (stroke, n = 160) and age-matched AF patients without ischemic strokes (control, n = 200). Results Compared with control, the stroke group had a larger LA dimension (4.5 ± 0.7 vs. 4.2 ± 0.6 cm, P < 0.001), larger LAA orifice area (5.3 ± 2.1 vs. 4.1 ± 1.7 cm2, P < 0.001), and slower LAA flow velocity (37 ± 19 vs. 51 ± 20 cm/s, P < 0.001). The stroke group had the chicken wing type less frequently than the control (34% vs. 50%, P = 0.003). After an adjustment for multiple potential confounding factors, the chicken wing type LAA had a decreased stroke risk (odds ratio 0.34, 95% confidence interval 0.14-0.84, P = 0.020). Patients with a chicken wing LAA had a smaller LAA orifice area (4.4 ± 1.6 vs. 4.9 ± 2.2 cm2, P = 0.013) and higher LAA velocity (55 ± 19 vs. 41 ± 20 cm/s, P < 0.001) than those with non-chicken wing LAA. Conclusion A chicken wing type of LAA was related to the less incidence of stroke. Our results suggest that the relationship between a specific LAA morphology and stroke might be partially explained by the change of the size and flow velocity of LAA. [ABSTRACT FROM AUTHOR]

Sex Differences in VT/VF or Death in MADIT-CRT Introduction Studies suggest that women with ischemic heart disease are less likely to experience appropriate ICD therapies for ventricular arrhythmias (VT/VF). We evaluated the influence of sex on arrhythmic events or death in subjects enrolled in MADIT-CRT. Methods and Results Arrhythmic event rates, defined as VT/VF treated with defibrillator therapy or all-cause death, were determined among 1,790 subjects enrolled in MADIT-CRT with documented 3-year follow-up. Predictors of VT/VF/death were identified using multivariate analysis. Ninety-one (21%) women and 466 (35%) men experienced VT/VF/death over the follow-up period. The overall probability of VT/VF/death was significantly lower in women versus men (HR 0.62; P < 0.001). The probability of VT/VF/death was the lowest in women with ischemic heart disease (HR 0.51; P = 0.003). In ICD subjects, the 3-year risk of VT/VF was lower in ischemic women versus men (P = 0.021), and in nonischemic women versus men (P = 0.049). The probability of VT/VF/death was significantly lower in women (HR 0.52; P = 0.007) and men (HR 0.74; P = 0.018) with LBBB who received CRT-D. Appropriate shock therapy strongly correlated with increased risk of death during postshock follow-up in women (HR 5.18; P = 0.001) and men (HR 1.63; P = 0.033); interaction P value of 0.034. Conclusion In this substudy of MADIT-CRT, sex, etiology of heart disease and type of device implanted significantly influenced subsequent risk for VT/VF or death. Women with ischemic heart disease and women with LBBB who received CRT-D had the lowest incidence of VT/VF or death when compared to men. Appropriate shock therapy was a strong predictor of death, particularly in women. [ABSTRACT FROM AUTHOR]

Second-Generation Cryoballoon versus RF Introduction There are limited comparative data on catheter ablation of atrial fibrillation (CAAF) using the second-generation cryoballoon (CB-2) versus point-by-point radiofrequency (RF). This study examines the acute/long-term CAAF outcomes using these 2 strategies. Methods and Results In this multicenter, retrospective, nonrandomized analysis, procedural and clinical outcomes of 1,196 patients (76% with paroxysmal AF) undergoing CAAF using CB-2 (n = 773) and open-irrigated, non-force sensing RF (n = 423) were evaluated. Pulmonary vein isolation was achieved in 98% with CB-2 and 99% with RF (P = 0.168). CB-2 was associated with shorter ablation time (40 ± 14 min vs. 66 ± 26 min; P < 0.001) and procedure time (145 ± 49 minutes vs. 188 ± 42 minutes; P < 0.001), but greater fluoroscopic utilization (29 ± 13 minutes vs. 23 ± 14 minutes; P < 0.001). While transient (7.6% vs. 0%; P < 0.001) and persistent (1.2% vs. 0%; P = 0.026) phrenic nerve palsy occurred exclusively with CB-2, other adverse event rates were similar between CB-2 (1.6%) and RF (2.6%); P = 0.207. However, freedom from AF/atrial flutter/tachycardia at 12 months following a single procedure without antiarrhythmic therapy was greater with CB-2 (76.6%) versus RF (60.4%); P < 0.001. While this difference was evident in patients with paroxysmal AF (P < 0.001), it did not reach significance in those with persistent AF (P = 0.089). Additionally, CB-2 was associated with reduced long-term need for antiarrhythmic therapy (16.7% vs. 22.0%; P = 0.024) and repeat ablations (14.6% vs. 24.1%; P < 0.001). Conclusion In this multicenter, retrospective, nonrandomized study, CAAF using CB-2 coupled with RF as occasionally required was associated with greater freedom from atrial arrhythmias at 12 months following a single procedure without antiarrhythmic therapy when compared to open-irrigated, non-force sensing RF, alone. [ABSTRACT FROM AUTHOR]

Cardiac Autoantibodies and AF Recurrence Introduction Recent evidence has suggested that autoantibodies may play an important role in the development of atrial fibrillation (AF). The predictive value of preprocedural autoantibodies against beta-1 adrenergic receptor (anti-β1-R) and M2-muscarinic acetylcholine receptor (anti-M2-R) for AF recurrence following cryoballoon-based pulmonary vein isolation (PVI) is still unclear. We aimed to determine the predictive value of preprocedural anti-β1-R and anti-M2-R levels for AF recurrence. Methods Eighty patients (mean age 54.25 ± 7.70 years; 40% female) with paroxysmal AF and preserved left ventricular function who underwent cryoballoon-based PVI were included in the study. Preprocedural anti-M2-R and anti-β1-R levels were measured with ELISA. Results At 1-year follow-up after ablation, late AF recurrence was observed in 17 (21.25%) patients. In the Cox regression model, including number of antiarrhythmic drugs, early AF recurrence, anti-β1-R levels >159.88 ng/mL, anti-M2-R levels >277.65 ng/mL, AF duration, and left atrial volume index, only anti-β1-R levels >159.88 ng/mL (HR: 4.281, P = 0.039) and anti-M2-R levels >277.65 ng/mL (HR: 4.313, P = 0.030) were found to be independent predictors of late AF recurrence. Anti-β1-R level >159.88 ng/mL was shown to predict late AF recurrence with a sensitivity of 70.59% and specificity of 90.48%. A cut-off value of 277.65 ng/mL for anti-M2-R level predicted AF recurrence with a sensitivity of 70.59% and specificity of 95.24%. Conclusion Preprocedural serum anti-β1-R and anti-M2-R levels are independent predictors of late AF recurrence following cryoballoon-based PVI in paroxysmal AF patients. Detection of preprocedural anti-β1-R and anti-M2-R levels may serve as a novel method for determination of paroxysmal AF patients who may not benefit from cryoballoon-based PVI. [ABSTRACT FROM AUTHOR]

TEE Probe and Esophageal Injury After AF Ablation Introduction The transesophageal echo probe (TEE) is commonly used before and during atrial fibrillation (AF) ablation under general anesthesia (GA). We sought to determine the potential contribution of the TEE probe to esophageal injury after pulmonary vein isolation (PVI) alone for paroxysmal AF. Methods and Results Seventy-six patients undergoing PVI with TEE, PVI/TEE, 16 undergoing PVI without TEE (PVI/No TEE), and 27 undergoing TEE without any left atrial ablation (TEE/No LA ablation) under GA were included. Posterior wall ablation was power (20-25 W) and time limited (electrogram attenuation or ≤30 s). Esophageal capsule endoscopy (n = 206) was performed pre- and post-procedure and at 2 weeks. Esophageal lesions were seen in 30% of PVI/TEE, 0% of patients in the PVI/No TEE (P = 0.009), and 22% of TEE/No LA ablation groups (P = 0.47 vs. PVI/TEE). There were no instances of esophageal bleeding, perforation, or need for gastrointestinal intervention. Self-resolving dysphagia was the only reported symptom (5%). All lesions healed within 2 weeks. There was no significant difference in the location or morphological appearance of esophageal lesions seen in the PVI/TEE versus TEE/No LA ablation groups. Conclusions Esophageal lesions were seen in 30% of patients undergoing PVI alone under GA with use of TEE and in a similar proportion (22%) of patients undergoing TEE in the absence of left atrial ablation. This study makes the preliminary observation that one must be cognizant of the TEE probe as a potential contributor to esophageal injury after AF ablation. Larger studies are needed to confirm these findings. [ABSTRACT FROM AUTHOR]

Introduction: There is no universally accepted method by which to diagnose clinical ventricular tachycardia (VT) due to cAMP-mediated triggered activity. Based on cellular and clinical data, adenosine termination of VT is thought to be consistent with a diagnosis of triggered activity. However, a major gap in evidence mitigates the validity of this proposal, namely, defining the specificity of adenosine response in well-delineated reentrant VT circuits. To this end, we systematically studied the effects of adenosine in a model of canine reentrant VT and in human reentrant VT, confirmed by 3-dimensional, pace- and substrate mapping. Methods and Results: Adenosine (12 mg [IQR 12-24]) failed to terminate VT in 31 of 31 patients with reentrant VT due to structural heart disease, and had no effect on VT cycle length (age, 67 years [IQR 53-74]); ejection fraction, 35% [IQR 20-55]). In contrast, adenosine terminated VT in 45 of 50 (90%) patients with sustained focal right or left outflow tract tachycardia. The sensitivity of adenosine for identifying VT due to triggered activity was 90% (95% CI, 0.78-0.97) and its specificity was 100% (95% CI, 0.89-1.0). Additionally, reentrant circuits were mapped in the epicardial border zone of 4-day-old infarcts in mongrel dogs. Adenosine (300-400 μg/kg) did not terminate sustained VT or have any effect on VT cycle length. Conclusion: These data support the concept that adenosine's effects on ventricular myocardium are mechanism specific, such that termination of VT in response to adenosine is diagnostic of cAMP-mediated triggered activity. [ABSTRACT FROM AUTHOR]

Renal Function and Outcomes After Defibrillator Implantation Background Implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) reduce mortality in patients with heart failure (HF) and left ventricular dysfunction. However, their efficacy in patients with chronic kidney disease (CKD) is controversial. Objective We examined the association between renal dysfunction and clinical outcomes in patients undergoing ICD and CRT defibrillator (CRTD) implantation. Methods Data were collected from the Israeli ICD registry. Estimated glomerular filtration rate (eGFR) at implantation was assessed using the modification of diet in renal disease formula. Primary outcome was all-cause mortality. Secondary outcomes included the composite endpoints of death or HF and death or ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]); any hospitalizations; first appropriate and inappropriate ICD therapy. Results During the study period (July 2010-November 2012), 2,811 patients were implanted with ICD or CRTD. One-year follow-up data were available for 730 ICD patients and 453 CRTD patients. Patients with eGFR < 30 mL/minute/1.73 m2 (n = 54, 4.6%) were older, had a higher prevalence of diabetes, hypertension, or ischemic heart disease. eGFR <30 mL/minute/1.73 m2 was associated with increased mortality risk in ICD (HR 5.4; 95% CI 1.5-19.2), but not in CRTD patients (HR 0.9; 95% CI 0.1-7.5). Renal dysfunction was associated with the composite endpoints of death or HF and death or VT/VF in ICD, but not in CRTD patients. Mean eGFR during follow-up decreased by 8.0 ± 4.3 mL/minute/1.73 m2 in ICD patients (P = 0.06) and by 1.8 ± 1.3 mL/minute/1.73 m2 in patients with CRTD (P = 0.2). Conclusion Based on this retrospective analysis, CKD is associated with adverse prognosis after ICD implantation, but not after CRTD implantation. GFR decreased in patients with ICD, but not in CRTD patients. [ABSTRACT FROM AUTHOR]

Long-Term Outcome of AF Ablation in MMV Patients Introduction It is unclear whether extended pulmonary vein antrum isolation (PVAI) plus nonpulmonary vein (non-PV) trigger elimination prevents more arrhythmia recurrence than PVAI alone in patients with mechanical mitral valve (MMV) undergoing AF ablation. This study compared the efficacy and long-term outcome of 2 ablation strategies-PVAI alone versus extended PVAI plus non-PV trigger elimination-for the treatment of AF in patients with MMV. Methods and Results One hundred and nine consecutive AF patients with MMV were divided into 2 groups: standard PVAI was performed in group 1 (N = 45); in group 2 (N = 64) PVAI was extended to the LA posterior wall, LA septum, and CS; and all non-PV triggers were eliminated. Patients were followed up for 3 years. At the 12th month, 7 (15.6%) patients in group 1, and 39 (60.9%) patients in group 2 were arrhythmia free (log-rank P < 0.001). Four patients (8.9%; 3 cases of AT and 1 case of AF) from group 1, and 12 patients (18.8%; 9 cases of AT, and 3 cases of AFL) from group 2 experienced very late recurrence. At 36 ± 7 months follow-up, the cumulative recurrence after a single procedure was 42/45 (93.3%) in group 1, and 37/64 (57.8%) in group 2 (log-rank P < 0.001). Conclusion Compared with the standard PVAI alone, a strategy including extended PVAI and non-PV trigger elimination is associated with a higher 12-month and long-term arrhythmia-free survival in patients with MMV undergoing AF ablation. Very late recurrence may occur years after the initial procedure with focal AT as the most common type of recurrent arrhythmia. [ABSTRACT FROM AUTHOR]

Role of Ischemia and Scar in CRT Patients with CAD Introduction Cardiac resynchronization therapy (CRT) recipients with ischemic cardiomyopathy (ICM) have scar segments that may limit ventricular resynchronization and clinical response. The impact of myocardial viability at the left ventricular (LV) pacing site on CRT response is poorly elucidated. Methods and Results A retrospective cohort of 160 ICM patients with single photon emission computed tomography-myocardial perfusion imaging before device implantation were included. Coronary venous angiography and chest radiographs helped classify segmental location of LV lead (LVL). The primary outcome was a composite of heart failure (HF) hospitalization and mortality at 3 years, and secondary outcome was change in systolic function at 6 months. The patients were divided into groups based on the myocardial substrate at the site of LVL: LVL on or adjacent to (1) normal myocardium (LVL-N, n = 64), (2) segmental scar (LVL-S, n = 62), and (3) scar and ischemia (LVL-SI, n = 34). Upon follow-up, 75 (47%) patients reached primary endpoint with a higher incidence noted in LVL-S (60%), and LVL-SI (53%), compared to 31% in LVL-N (P = 0.004). Kaplan Meier method demonstrated poor event free survival for primary outcome in LVL-S (P = 0.002), and LVL-SI (P = 0.03). In Cox proportional hazard model, LVL-S (HR: 2.26, P = 0.004), and LVL-SI (1.9, P = 0.047) were independent predictors of primary outcome. Conclusion In CRT recipients with ICM, scar and reversible ischemia in or adjacent to LV pacing site were independent predictors of HF hospitalization and death. [ABSTRACT FROM AUTHOR]

T-Wave Analysis for the Subcutaneous ICD Background The subcutaneous cardioverter-defibrillator (S-ICD) relies on a pre-implantation QRS-T morphology screening (TMS) of the ECG to assure that it reliably detects the QRS complexes and T waves. The prevalence and clinical characteristics of the patients who fail this TMS is unknown. Methods and Results QRS-TMS was done in 230 consecutive ICD outpatients (75% male, age 57 ± 15 years) without an indication for cardiac pacing, using an ECG simulating the 3 sensing vectors of the S-ICD (TMS-ECG). Patients were defined suitable when at least 1 sensing vector was considered appropriate in both supine and standing position. In total, 7.4% of patients, who were all male, were considered not suitable for a S-ICD according to the TMS-ECG. Independent predictors for TMS failure were hypertrophic cardiomyopathy (HCM; odds ratio [OR] 12.6), a heavy weight (OR 1.5), a prolonged QRS duration (OR 1.5) and a R:T ratio <3 in the lead with the largest T wave on a standard 12-lead surface ECG (OR 14.6). Conclusion In patients without an indication for pacing, 7.4% would have been not suitable for a S-ICD according to the TMS. HCM, a heavy weight, a prolonged QRS duration and a R:T ratio <3 in the ECG lead with the largest T wave were independently associated with TMS failure. These data might alert physicians that selection of patients for a S-ICD should be considered with special caution in certain patient groups, because they may not satisfy ECG criteria for adequate sensing. [ABSTRACT FROM AUTHOR]

ICDs and Signal Analyses Introduction Antitachycardia pacing (ATP), a quick, painless, and effective therapy available in implantable cardioverter-defibrillators (ICDs), can terminate most, but not all, sustained ventricular tachycardias (VTs). This study investigated the possible ventricular electrogram (EGM) factors for predicting the effectiveness of ATP therapy from ICD recordings. Methods and Results In this study, we analyzed 113 EGMs of VT episodes acquired from 20 patients who received ATP or shock to terminate tachyarrhythmias during follow-up after ICD implantations. The relationship between the outcome of ATP and VT EGM features (such as voltage, width, cycle length, and beat-to-beat morphologic variation) was investigated. The divergence (beat-to-beat morphologic variation) of the VT EGMs was determined by calculating the total deviation of all EGMs away from the average template after all VT EMGs were aligned. In total, 72 (63.7%) successful (Group I) and 41 (36.3%) unsuccessful (Group II) ATP therapy episodes were analyzed. The mean amplitude, cycle length, and EGM width were similar between these 2 groups (P > 0.05). A multivariate analysis demonstrated that the only predictor of successful ATP was the divergence among the VT EGMs (0.56 ± 0.32 vs 1.07 ± 0.64, P < 0.001, for Groups 1 and 2, respectively). The optimal cutoff value for determining a successful ATP therapy was 0.73 (with an area under the curve of 0.769, sensitivity of 81.9% [95% CI = 71.1-90.0], and specificity of 65.9% [95% CI = 49.4-79.9], P < 0.0001). Conclusion Signal analyses from stored EGMs of VT can predict the response of ATP therapy in patients with ICD implantations. A lesser ventricular beat-to-beat morphologic variation in the intracardiac recordings from ICDs correlated with a higher probability of a successful ATP. [ABSTRACT FROM AUTHOR]

Cryoballoon-Induced Phrenic Nerve Injury Introduction Hemi-diaphragmatic paralysis is the most common complication associated with cryoballoon ablation for atrial fibrillation, yet the histopathology of phrenic nerve injury has not been well described. Methods and Results A preclinical randomized study was conducted to characterize the histopathology of phrenic nerve injury induced by cryoballoon ablation and assess the potential for electromyographic (EMG) monitoring to limit phrenic nerve damage. Thirty-two dogs underwent cryoballoon ablation of the right superior pulmonary vein with the objective of inducing phrenic nerve injury. Animals were randomized 1:1 to standard monitoring (i.e., interruption of ablation upon reduction in diaphragmatic motion) versus EMG guidance (i.e., cessation of ablation upon a 30% reduction in the diaphragmatic compound motor action potential [CMAP] amplitude). The acute procedural endpoint was achieved in all dogs. Phrenic nerve injury was characterized by Wallerian degeneration, with subperineural injury to large myelinated axons and evidence of axonal regeneration. The degree of phrenic nerve injury paralleled the reduction in CMAP amplitude (P = 0.007). Animals randomized to EMG guidance had a lower incidence of acute hemi-diaphragmatic paralysis (50% vs 100%; P = 0.001), persistent paralysis at 30 days (21% vs 75%; multivariate odds ratio 0.12, 95% confidence interval [0.02, 0.69], P = 0.017), and a lesser severity of histologic injury (P = 0.001). Mature pulmonary vein ablation lesion characteristics, including circumferentiality and transmurality, were similar in both groups. Conclusion Phrenic nerve injury induced by cryoballoon ablation is axonal in nature and characterized by Wallerian degeneration, with potential for recovery. An EMG-guided approach is superior to standard monitoring in limiting phrenic nerve damage. [ABSTRACT FROM AUTHOR]

ECG Predictors of Electroanatomic Scar in ARVC Introduction The extent of right ventricular (RV) electroanatomic scar (EAS) detected by endocardial voltage mapping (EVM) is a powerful invasive predictor of arrhythmic outcome in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Electrocardiogram (ECG) and signal-averaged ECG are noninvasive tools of established clinical value for the diagnosis of electrical abnormalities in ARVC. This study was designed to assess the role of ECG and SAECG abnormalities for noninvasive estimation of the extent and regional distribution of RV-EAS and prediction of scar-related arrhythmic risk. Methods and Results The study population included 49 consecutive patients (38 males, median age 35 years) with a definite diagnosis of ARVC and an abnormal EVM by CARTO system. At univariate analysis, the presence of epsilon waves, the degree of RV dilation, the severity of RV dysfunction, and the extent of negative T waves correlated with RV-EAS% area. Normal T-waves were associated with a median RV-EAS% area of 4.9% (4.5-6.4), negative T waves in V1-V3 of 22.0% (8.5-30.6), negative T waves in V1-V3 extending to lateral precordial leads (V4-V6) of 26.8% (11.5-35.2), and negative T waves in both precordial (V2-V6) and inferior leads of 30.2% (24.8-33.0) (P < 0.001). At multivariate analysis, the extent of negative T waves remained the only independent predictor of RV-EAS% area (B = 4.4, 95%CI 1.3-7.4, P = 0.006) and correlated with the arrhythmic event-rate during follow-up (P = 0.03). Conclusions In patients with ARVC, the extent of negative T-waves across 12-lead ECG allows noninvasive estimation of the amount of RV-EAS and prediction of EAS-related arrhythmic risk. [ABSTRACT FROM AUTHOR]

Arrhythmia Termination and Long-Term Outcome Background The influence of procedural arrhythmia termination on long-term single-procedure clinical outcome in patients with non-paroxysmal atrial fibrillation (AF) remains controversial. Methods An individualized stepwise ablation strategy was used in 200 consecutive patients with non-paroxysmal AF who underwent first-time radiofrequency catheter ablation, with pulmonary vein isolation and sinus rhythm (SR) restoration as the primary endpoints. Results SR was restored by ablation in 94 patients, including 32 with AF directly and 62 with intermediate atrial tachycardia (AT). Cardioversion was performed to restore SR in 106 patients, including 31 with intermediate AT, and 75 with sustained AF. During a mean follow-up of 50.0 ± 9.3 months, single-procedure success was achieved in 99 (49.5%) patients. There was a significant difference in long-term success between patients with SR restoration by ablation and by cardioversion (63.8% vs 36.8%; P < 0.001), but not between patients with AF termination by ablation and by cardioversion (53.6% vs 42.7%; P = 0.146). SR restoration by ablation (odds ratio = 3.032; 95% confidence interval = 1.703-5.398; P < 0.001) was the only predictor of single-procedure success by logistic regression analyses. In patients with intermediate AT (n = 93), AT termination by ablation was associated with a higher success rate than AT termination by cardioversion (62.9% vs 22.6%; P < 0.001). Conclusions SR restoration and AT termination by ablation were both associated with an improved long-term single-procedure clinical outcome in patients with non-paroxysmal AF. [ABSTRACT FROM AUTHOR]

Left Atrial Sphericity Predicts AF Ablation Outcome Background Atrial fibrillation (AF) ablation outcome is mainly determined by atrial remodeling that, nowadays, is only estimated through clinical presentation (persistent vs. paroxysmal) and left atrial (LA) dimension. The aim of the study was to stage the atrial remodeling process using the Left Atrial Sphericity (LASP) and determine whether this technique may help to predict AF ablation outcome. Methods Consecutive patients who underwent contrast-enhanced cardiac magnetic resonance angiography before AF ablation were included in the study. Three-dimensional reconstruction of LA excluding pulmonary veins and the LA appendage was used to define the LA cavity. The LASP was automatically obtained with self-customized software. Results 106 patients were included and categorized in 3 groups (Gs): discoid-LA (G1), intermediate-LA (G2), and spherical-LA (G3). The G3 patients had larger LA anteroposterior diameter than G1 and G2 patients (47 ± 7 vs 43 ± 6 and 39 ± 5mm; P < 0.001), greater LA volume (90 ± 39 vs 86 ± 24 and 73 ± 20 mm; P = 0.012), and higher prevalence of persistent AF (75% vs 48% and 29%; P = 0.034) structural heart disease (75% vs 19% and 19%; P < 0.001), and AF recurrence at 12 months follow-up (58% vs 29% and 5%, P < 0.001). The LASP had linear correlation to predicted probability of recurrence. Multivariate analysis identified LASP (OR 1.320 [1.096-1.591], P = 0.004) and hypertension (OR 3.694 [1.282-10.645]; P = 0.016) as independent risk factors for arrhythmia recurrence. Conclusion Left Atrial Sphericity is a new independent predictor of recurrence after AF ablation and may be useful in selecting the best candidates for AF ablation. [ABSTRACT FROM AUTHOR]

Late Gadolinium Enhancement and Arrhythmias. Introduction : The extent of left ventricular (LV) scar, characterized by late gadolinium enhancement cardiac MRI (LGE-CMR), has been shown to predict the occurrence of ventricular arrhythmias in implantable cardioverter defibrillator (ICD) recipients. However, the specificity of LGE-CMR for sudden cardiac death (SCD) versus non-SCD is unclear. The aim of this retrospective, observational study was to evaluate this relationship in a cohort of ICD recipients. Methods and Results : We included consecutive patients who had undergone LGE-CMR before ICD implantation over a 4-year period (2006-2009). Scar (defined as myocardium with a signal intensity ≥50% of the maximum in scar tissue) was characterized in terms of percent scar and number of transmural LV scar segments in a 17-segment model. The endpoints were appropriate ICD therapy and all-cause mortality. Sixty-four patients (average age 66 ± 11 years, 51 male, median LVEF 30%) were included. During 42 ± 13 months follow-up, appropriate ICD therapy occurred in 28 patients (44%), and 14 patients (22%) died. Number of transmural scar segments (P = 0.005) and percentage LV scar (P = 0.03) were both significantly associated with appropriate ICD therapy. However, neither number of transmural scar segments (P = 0.32) or percent LV scar (P = 0.59) was significantly associated with all-cause mortality. Conclusion : In this observational study, in medium-term follow-up, the extent of LV scar characterized by LGE-CMR was strongly associated with the occurrence of spontaneous ventricular arrhythmias but not all-cause mortality. We hypothesize that scar quantification by LGE-CMR may be more specific for SCD than non-SCD, and may prove a valuable tool for the selection of patients for ICD therapy. (J Cardiovasc Electrophysiol, Vol. 24, pp. 430-436, April 2013) [ABSTRACT FROM AUTHOR]

Long-Term Outcome of NPV AF Ablation. Introduction: Data regarding the long-term outcome of catheter ablation in patients with nonpulmonary vein (NPV) ectopy initiating atrial fibrillation (AF) are limited. We aimed to evaluate the long-term result of patients with AF who had NPV triggers and underwent catheter ablation. Methods and Results: The study included 660 consecutive patients (age 54 ± 11 years old, 477 males) who had undergone catheter ablation for AF. Group 1 consisted of 132 patients with AF initiating from the NPV, and group 2 consisted of 528 patients with AF initiating from pulmonary vein (PV) triggers only. Patients from Group 1 were younger than those from Group 2 (51 ± 12 years old vs 54 ± 11 years old, P = 0.001) and were more likely to be females (34.4% vs 25.8%, P = 0.049). The incidences of nonparoxysmal AF (36.4% vs 16.3%, P < 0.001) and right atrial (RA) enlargement (31.3% vs 19%, P = 0.004) were higher, and the biatrial substrates were worse in Group 1 than those in Group 2 (left atrial voltage 1.5 ± 0.7 mV vs 1.9 ± 0.7 mV, P < 0.001, RA voltage 1.6 ± 0.5 mV vs 1.8 ± 0.6 mV, P = 0.014). During a follow-up period of 46 ± 23 months, there was a higher AF recurrence rate in Group 1 than in Group 2 (57.6% vs 38.8%, P < 0.001). The independent predictors of AF recurrence were NPV trigger (P < 0.001, HR 2, 95% CI 1.4-2.85), nonparoxysmal AF (P = 0.021, HR 1.55, 95% CI 1.07-2.24), larger left atrial diameter (P = 0.002, HR 1.04, 95% CI 1.02-1.07) and worse left atrial substrate (P = 0.028, HR 1.3, 95% CI 1.03-1.64). Conclusion: Compared to AF originating from the PV alone, AF originating from the NPV ectopy showed a worse outcome. (J Cardiovasc Electrophysiol, Vol. 24, pp. 250-258, March 2013) [ABSTRACT FROM AUTHOR]

Nonlinear Analysis of Atrial Fibrillation. Introduction: Currently, the identification of complex fractionated atrial electrograms (CFEs) in the substrate modification is mostly based on cycle length-derived algorithms. The characteristics of the fibrillation electrogram morphology and their consistency over time are not clear. The aim of this study was to optimize the detection algorithm of crucial CFEs by using nonlinear measure electrogram similarity. Methods and Results: One hundred persistent atrial fibrillation patients that underwent catheter ablation were included. In patients who required CFE ablation (79%), the time-domain fibrillation signals (6 seconds) were acquired for a linear analysis (mean fractionation interval and dominant frequency [DF]) and nonlinear-based waveform similarity analysis of the local electrograms, termed the similarity index (SI). Continuous CFEs were targeted with an endpoint of termination. Predictors of the various signal characteristics on the termination and clinical outcome were investigated. Procedural termination was observed in 39% and long-term sinus rhythm maintenance in 67% of the patients. The targeted CFEs didn't differ based on the linear analysis modalities between the patients who responded and did not respond to CFE ablation. In contrast, the average SI of the targeted CFEs was higher in termination patients, and they had a better outcome. Multivariate regression analysis showed that a higher SI independently predicted sites of termination (≥0.57; OR = 4.9; 95% CI = 1.33-18.0; P = 0.017). Conclusions: In persistent AF patients, a cycle length-based linear analysis could not differentiate culprit CFEs from bystanders. This study suggested that sites with a high level of fibrillation electrogram similarity at the CFE sites were important for AF maintenance. (J Cardiovasc Electrophysiol, Vol. 24, pp. 280-289, March 2013) [ABSTRACT FROM AUTHOR]

Early Recurrence in STAR-AF. Background: Early recurrences of atrial tachyarrhythmias (ERAT) are common after atrial fibrillation (AF) ablation, and predict late recurrences (LR). We sought to determine the impact of different ablation strategies on ERAT and LR. Methods and Results: The STAR-AF trial randomized 100 patients with paroxysmal or persistent AF to ablation of complex fractionated electrograms (CFAE) alone, pulmonary vein isolation (PVI) alone, or combined PVI + CFAE. Patients were followed for 12 months. ERAT was defined as any recurrence of AF, atrial tachycardia, or flutter (AT/AFL) >30 seconds during the first 3 months of follow-up. LR was defined as any recurrence of AF/AT/AFL >30 seconds 3-12 months post. Forty-nine patients experienced ERAT. The index ablation strategy was the only independent predictor of ERAT on multivariate analysis (HR 2.24 PVI vs PVI + CFAE; and HR 2.65 CFAE vs PVI + CFAE). Fifty-two patients experienced LR. The presence of ERAT (HR 3.23), the use of antiarrhythmic drug (AAD) in the first 3 months postablation (HR 2.85), and the index ablation strategy were independently associated with LR (HR 3.42 PVI vs PVI + CFAE; HR 4.72 CFAE vs PVI + CFAE). Thirty-five of 49 (71%) patients with ERAT and 17 (33%) of 51 patients without ERAT had LR (P < 0.0001). Among patients with ERAT, increased left atrium size (HR 1.08), the use of AAD in the first 3 months postablation (HR 2.86) and the index ablation strategy were independently associated with LR (HR 4.77 PVI vs PVI + CFAE; HR 4.45 CFAE vs PVI + CFAE). Conclusion: ERAT is common following AF ablation and is strongly associated with LR. Although CFAE ablation alone results in higher rates of early and LR, the addition of CFAE to PVI results in increased long-term success without an increase in ERAT. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1295-1301, December 2012) [ABSTRACT FROM AUTHOR]

Impact of Recalls on ICD Utilization. Introduction: The study was designed to evaluate the feasibility and performance of right ventricular (RV) mid-septal versus apical implantable defibrillator (ICD) lead placement. Methods and Results: SEPTAL is a randomized, noninferiority trial, which randomly assigned patients to implantation of ICD leads in the RV mid-septum versus apex, with a primary objective of comparing the implant success rate of implant at each site, based on strict electrical predefined criteria. We also compared the (1) pacing lead characteristics, (2) rates of appropriate and inappropriate ICD therapies, and (3) all-cause mortality between the 2 sites at 1 year. The trial enrolled 215 patients (mean age = 59.7 ± 12.4 years, mean LVEF = 34.0 ± 14.2%, 84.2% men), of whom 148 (68.8%) presented with ischemic heart disease. The ICD indication was primary prevention in 117 patients (54.4%). The lead was successfully implanted in 96/107 patients (89.7%) assigned to the RV mid-septum, and in 99/108 (91.7%) assigned to the apex (ns). The 1-year rate of lead-related adverse events was similar in both groups. A total of 8 first inappropriate ICD therapies (7.9%) were delivered in the RV mid-septal group, versus 8 (7.8%) in the apical group (ns), while first appropriate therapies were delivered to 22 (21.4%) and 24 patients (23.8%), respectively (ns). All-cause mortality was 7.9% in the RV mid-septal versus 2.9% in the RV apical group (ns). Conclusion: This study confirmed the technical feasibility and noninferior performance of ICD leads implanted in the RV mid-septum versus the apex. (J Cardiovasc Electrophysiol, Vol. 23, pp. 853-860, August 2012) [ABSTRACT FROM AUTHOR]

Prognostic Impact of Inappropriate Shocks. Introduction: Recent studies suggest a worse impact of inappropriate shock therapies on the outcome of patients with an implantable cardioverter-defibrillator (ICD). However, it is not known whether the worse impact is attributed to the ICD shock itself or due to the underlying heart disease. The aim of the study was to evaluate the impact of inappropriate ICD shocks on clinical outcome by comparing ICD shocks triggered by atrial fibrillation (AF) with shocks caused by lead failure. Methods and Results: A total of 1,411 consecutive patients of the prospective single-center ICD-registry Ludwigshafen who underwent an ICD implantation between 1992 and 2008 for primary or secondary prevention of sudden cardiac death were analyzed. During the median follow-up of 3 years, 297 (21%) patients experienced inappropriate ICD shocks. Sixty percent of patients had inappropriate shocks due to AF and 24% due to lead defect or T-wave oversensing. Multiple ICD shocks (≥2) triggered by AF were associated with a worse prognosis, whereas a single shock due to AF or 1 or multiple shocks resulting from lead failure were not. ICD shocks caused by AF occurred more often in tandem with a serious adverse event than in patients with a lead failure (15% vs 6%, P < 0.05). Conclusion: Multiple ICD shocks triggered by AF are associated with a worse prognosis in ICD patients, whereas a single shock due to AF or shocks resulting from lead failure are not. These data support that the ICD shock itself has no worse impact on the outcome of ICD patients. (J Cardiovasc Electrophysiol, Vol. 23, pp. 735-740, July 2012) [ABSTRACT FROM AUTHOR]

Depression and Cardiac Resynchronization Therapy. Background: The relationship between depression and heart failure is neither coincidental nor trivial, since depression is a powerful predictor of re-hospitalization and mortality. We prospectively studied the prevalence and impact of depression on the clinical outcomes of patients attending for cardiac resynchronization therapy (CRT). We specifically examined whether patients with depression have a different rate of response to CRT and whether CRT has an effect on depressive symptoms. Methods: Sixty-eight recipients of CRT systems were included. The depressive status was evaluated before implant and after 6 months by a structured diagnostic interview measuring Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria of major depression and by a self-report questionnaire (Center for Epidemiological Studies Depression Scale, CES-D). The CRT response was assessed at 6 months by a clinical composite score. Results: At inclusion, DSM-IV criteria of major depression were identified in 41% of the population, while using the self-report questionnaire 65% were observed to have mild to major depressive symptoms (CES-D ≥ 16). Only 4 patients were taking antidepressants. At 6 months, 75% were considered responders to CRT. Response to CRT did not differ between those with and without depression at baseline. The rate of patients with depression at 6 months was significantly lower in responders to CRT compared with nonresponders. Conclusions: We found a high prevalence of depressive symptoms in patients receiving CRT systems. Patients with depression should not be excluded from CRT, because they demonstrate a similar rate of response than the persons without depression and the responders are less likely to be depressed at 6 months. (J Cardiovasc Electrophysiol, Vol. 23, pp. 631-636, June 2012) [ABSTRACT FROM AUTHOR]

Ablation and Progression of Atrial Fibrillation. Objective: The objective was to determine the effect of radiofrequency catheter ablation (RFA) on progression of paroxysmal atrial fibrillation (AF). Background: Progression to persistent AF may occur in up to 50% of patients with paroxysmal AF receiving pharmacological therapy. Hypertension, age, prior transient ischemic event, chronic obstructive pulmonary disease, and heart failure (HATCH score) have been identified as independent risk factors for progression of AF. Methods: RFA was performed in 504 patients (mean age: 58 ± 10 years) to eliminate paroxysmal AF. A repeat RFA procedure was performed in 193 patients (38%). Clinical variables predictive of outcome and their relation to progression of AF after RFA were assessed using multivariate analysis. Results: At a mean follow-up of 27 ± 12 months after RFA, 434/504 patients (86%) were in sinus rhythm; 49/504 patients (9.5%) continued to have paroxysmal AF; and 14 (3%) were in atrial flutter. Among the 504 patients, 7 (1.5%) progressed to persistent AF. In patients with recurrent AF after RFA, paroxysmal AF progressed to persistent AF in 7/56 (13%, P < 0.001). The progression rate of AF was 0.6% per year after RFA (P < 0.001 compared to 9% per year reported in pharmacologically treated patients). Age >75 years, duration of AF >10 years and diabetes were independent predictors of progression to persistent AF. The HATCH score was not significantly different between patients with paroxysmal AF who did and did not progress to persistent AF (0.7 ± 0.8 vs 1.0 ± 0.5, P = 0.3). Conclusions: Compared to a historical control group of pharmacologically treated patients with paroxysmal AF, RFA appears to reduce the rate of progression of paroxysmal AF to persistent AF. Age, duration of AF, and diabetes are independent risk factors for progression to persistent AF after RFA. (J Cardiovasc Electrophysiol, Vol. 23, pp. 9-14, January 2012) [ABSTRACT FROM AUTHOR]

Pacemakers and ICDs in Myotonic Dystrophy. Introduction: We assessed implant rates, indications, characteristics, and outcomes in patients with the neuromuscular disease, myotonic dystrophy type 1 (DM1) receiving a pacemaker or an implantable cardioverter-defibrillator (ICD). Methods and Results: Device use was evaluated in a prospective, multicenter registry of 406 genetically confirmed adult patients followed for 9.5 ± 3.2 years. Forty-six (11.3%) had or received a pacemaker and 21 (5.2%) received an ICD. Devices were primarily implanted for asymptomatic conduction abnormalities and left ventricular (LV) systolic dysfunction. However, 7 (15.2%) pacemakers were implanted for third-degree atrioventricular block and 6 (28.6%) ICDs were implanted for ventricular tachyarrhythmias (ventricular tachycardia [VT] or fibrillation [VF]). Patients receiving devices were older and more frequently had heart failure, LV systolic dysfunction, atrial tachyarrhythmias, and ECG conduction abnormalities compared to nondevice patients. Five (10.9%) pacemaker patients underwent upgrade to an ICD, 3 for LV systolic dysfunction, 1 for VT/VF, and 1 for progressive conduction disease. Seventeen (27.4%) of the 62 patients with devices were pacemaker-dependent at last follow-up. Three (14.3%) ICD patients had appropriate therapies. Twenty-four (52.2%) pacemaker patients died including 13 of respiratory failure and 7 of sudden death. Seven (33.3%) ICD patients died including 2 of respiratory failure and 3 of sudden death. The patients with ICDs and sudden death all had LV systolic dysfunction and 1 death was documented due to inappropriate therapies. Conclusions: DM1 patients commonly receive antiarrhythmia devices. The risk of VT/VF and sudden death suggests that ICDs rather than pacemakers should be considered for these patients. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1369-1375, December 2011) [ABSTRACT FROM AUTHOR]

Very Early Recurrence of AF. Introduction: Early restoration of sinus rhythm following ablation of atrial fibrillation (AF) facilitates reverse atrial remodeling and improves the long-term outcome. The purpose of this study was to determine the predictors and outcome in patients with very early AF recurrences (< 2 days). Methods and Results: Ablation was performed in 339 consecutive AF patients (paroxysmal AF = 262). Biatrial voltage was mapped during sinus rhythm. If recurrent AF occurred within 2 days following the ablation, electrical cardioversion was performed to restore sinus rhythm. Very early recurrences of AF occurred in 39 (15%) patients with paroxysmal AF and 26 (34%) with nonparoxysmal AF. Patients with very early recurrence had a higher incidence of nonparoxysmal AF (40% vs 18.6%, P< 0.001), requirement of electrical cardioversion during procedure, larger left atrial (LA) diameter (43 ± 7 vs 39 ± 6 mm, P< 0.001), lower left ventricular ejection fraction (54 ± 10% vs 59 ± 7, P< 0.001), longer procedural time, and lower LA voltage (1.5 ± 0.7 vs 1.9 ± 0.8 mV, P< 0.001). A multivariate analysis revealed that the independent predictors of a very early recurrence were a longer procedural time and lower LA voltage. During a follow-up of 13 ± 5 months, a very early recurrence did not predict the long-term outcome of a single procedure recurrence in the patients with paroxysmal AF, but was associated with a late recurrence in the nonparoxysmal AF patients. Conclusion: Very early recurrence occurred in patients with paroxysmal AF is not associated with long-term recurrence. Nonparoxysmal AF is an independent predictor of late recurrence of AF in patients with very early recurrence. (J Cardiovasc Electrophysiol, Vol. pp. 1-6) [ABSTRACT FROM AUTHOR]