Premature ventricular complex site of origin and ablation outcomes in patients with prior myocardial infarction.

BACKGROUND: Frequent premature ventricular complexes (PVCs) are common after a myocardial infarction (MI), but data on PVC ablation in this population are limited. OBJECTIVE: The purpose of this study was to analyze data on PVC ablation in post-MI patients. METHODS: Three hundred thirty-two patients with frequent PVCs and left ventricular (LV) dysfunction were prospectively studied. Data from 67 patients (20%; age 63 ± 10 years; 65 men [93%]) with previous MI were compared with the remaining 265 patients. RESULTS: PVCs in post-MI patients originate predominantly from the LV (92% LV vs 6% right ventricle [RV]; P <.001). The most frequent sites of origin (SOO) were MI scar in 23 patients (34%) and left ventricular outflow tract (LVOT) in 22 patients (33%). A papillary muscle origin was more frequent in post-MI patients (16% vs 4%; P = .001), whereas an RV outflow tract origin was less frequent (1% vs 33%; P <.001) compared to patients without MI. In post-MI patients, PVC burden decreased from 29% ± 12% at baseline to 4.6% ± 7% (P <.001); left ventricular ejection fraction (LVEF) improved from 33.6% ± 8% to 42% ± 10% (P <.001); and New York Heart Association functional class improved from 2.1 ± 0.7 to 1.4 ± 0.5 points (P <.001) at 12 months. Compared with the remaining 265 patients, there were no differences in acute ablation success (85% vs 85%; P = .45), complication rate (6% vs 6%; P = .41), or absolute improvement in LVEF (8.8 ± 10 vs 9.9 ± 11 absolute points; P = .38). CONCLUSION: PVC ablation significantly improves cardiac function and functional status in post-MI patients. PVCs predominantly originate from MI scar and LVOT. A papillary muscle SOO was found to be strongly associated with previous MI.

Antitachycardia pacing for shock prevention in patients with hypertrophic cardiomyopathy and ventricular tachycardia.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) carries an increased risk of sudden death due to ventricular arrhythmias (VAs). The implantable cardioverter-defibrillator (ICD) is a well-established therapy for treatment of VA. Monomorphic ventricular tachycardias (MVTs) are frequent in HCM patients and suitable for antitachycardia pacing (ATP) termination. OBJECTIVE: The purpose of this study was to describe ventricular tachycardia (VT) characteristics in a population of HCM patients with ICD and to study the effectiveness and safety of ATP for MVT. METHODS: Data were obtained from the multicenter prospective observational UMBRELLA trial, which included all patients with HCM and ICD followed by the CareLink Monitoring System. All episodes of VA were collected and analyzed. ATP effectiveness and safety were described, and factors related to ATP effectiveness were studied with generalized estimating equation (GEE) models. RESULTS: Among 251 patients followed for 47 months, 67 (26.7%) were implanted as secondary prevention. Fifty-six patients presented 326 episodes of VA (286 [87%] MVT). Mean cycle length was 312 ± 64 ms. Among 264 MVTs that received ICD therapy, 202 (76.5%) were ATP terminated. The first ATP burst was effective in 169 episodes (68.4%), and overall effectiveness of the first or second ATP burst was 73.8%. Multivariate GEE-adjusted analysis showed 2 variables related to ATP effectiveness: programming fast VT zone On vs Off (odds ratio [OR] 2.4; 95% confidence interval [CI] 1.5-5.2; P = .03) and programming ≥2 ATP bursts vs 1 burst only (OR 1.6; 95% CI 1.2-3.4; P = .04; and OR 2.9; 95% CI 1.8-6.3; P = .02; respectively). CONCLUSION: MVT is the predominant VA in HCM patients with ICD. ATP is highly effective in terminating the majority of MVTs, and its proved effectiveness should guide device selection and programming in order to avoid unnecessary high-energy shocks.

Influence of baseline QRS on the left ventricular ejection fraction recovery after frequent premature ventricular complex ablation.

AIMS: Frequent premature ventricular complexes (PVCs) can induce or worsen left ventricular systolic dysfunction. We aimed to investigate the influence of the baseline QRS in the response after PVC ablation in patients with depressed left ventricular ejection fraction (LVEF). METHODS AND RESULTS: Two hundred and fifteen [59 ± 13 years old, 152 (71%) men] consecutive patients with left ventricular (LV) systolic dysfunction and frequent PVCs referred for ablation were included and followed-up for 12 months. Echocardiographic response was defined as an improvement of at least five absolute points in LVEF. Clinical, electrocardiogram, and electrophysiological characteristics were analysed. Mean baseline QRS duration was 110 ms [97-140]. Premature ventricular complex burden significantly decreased after ablation from 23% [16-33] at baseline to 1% [0-8] at 12 months, P < 0.001. Mean PVC burden reduction was 18 [8-30] points. There was a significant improvement of LVEF from 35% [29-40] at baseline to 44% [35-55] at 12 months, P < 0.001. One hundred and thirty (61%) patients were considered as echocardiographic responders. Baseline QRS duration (ms) [odds ratio (OR) 0.98 (0.97-0.99), P = 0.01] was an independent predictor of echocardiographic response. Mean LVEF improvement was 16 [10-21] points when the baseline QRS duration was <90 ms; 12 [4-20] when it was 90-110 ms; 5 [0-15] when it was 110 ± 130 ms; and 0 [0-6] points when it was >130 ms. CONCLUSIONS: In patients with LV systolic dysfunction, intrinsic QRS duration is inversely related to the probability and the degree of echocardiographic response after frequent PVC ablation. Patients with a QRS duration >130 ms at baseline have the poorer response after ablation.

Mortality and morbidity reduction after frequent premature ventricular complexes ablation in patients with left ventricular systolic dysfunction.

AIMS: Ablation of frequent premature ventricular complexes (PVCs) improves left ventricular ejection fraction in patients with left ventricular (LV) systolic dysfunction. This study aims to evaluate the long-term hard outcomes and potential prognostic variables in this population. METHODS AND RESULTS: Prospective multicentre study including 101 consecutive patients [56 ± 12 years old, 62 (61%) men] with LV systolic dysfunction and frequent PVCs who underwent PVC ablation before November 2015. The last evaluation performed was considered the long-term follow-up (LTFUP) evaluation. Mean follow-up was 34 ± 16 months (range 24-84 months). Ablation was successful in 95 (94%) patients. There was a significant reduction in the PVC burden from 21 ± 12% at baseline to 3.8 ± 6% at LTFUP, P < 0.001. Left ventricular ejection fraction improved from 32 ± 8% at baseline to 39 ± 12% at LTFUP (P < 0.001) and New York Heart Association class from 2.2 ± 0.6% to 1.3 ± 0.6% (P < 0.001). Brain natriuretic peptide levels decreased from 136 (78-321) to 68 (32-144) pg/mL (P = 0.007). Most of this improvement occurs during the first 6 months after ablation. Persistent abolition of at least 18 points of the baseline PVC burden was independently and inversely associated with the composite endpoint of cardiac mortality, cardiac transplantation, or hospitalization for heart failure during follow-up [hazard ratio 0.18 (0.05-0.66), P = 0.01]. CONCLUSION: In patients with LV systolic dysfunction, ablation of frequent PVCs induces a significant improvement in functional, structural, and neurohormonal status, which persists at LTFUP. A sustained reduction in the baseline PVC burden is associated with a lower risk of cardiac mortality, cardiac transplantation, or hospitalization for heart failure during follow-up.

Atrial Fibrillation Ablation in Adults With Repaired Congenital Heart Disease.

The incidence of atrial fibrillation (AF) in congenital heart disease (CHD) adults has increased in the past decades due to a longer life expectancy of this population where the subjects are exposed to cardiac overflow, overpressure and structural changes for years. The literature regarding AF ablation in repaired CHD adults emphasizes the importance of intracardiac echocardiography (ICE) to perform the transseptal puncture and the ablation procedure in the left atrium (LA), both effectively and safely. In small case control studies, where the predominant congenital cardiomyopathy was the atrial septal defect, the most common strategy for ablation was antral isolation of the pulmonary veins showing results, at one year follow-up, similar to those in the general population. The positive results of AF ablation so far, in this specific population, widen the range of therapeutic options for a group of patients whose only chance has been pharmacological treatment, which has proved to be inefficacious in most of the cases and not free from adverse events.

Brief Report: Translation and Adaptation of the Theory of Mind Inventory to Spanish.

The Theory of Mind Inventory is an informant measure designed to evaluate children's theory of mind competence. We describe the translation and cultural adaptation of the inventory by the following process: (1) translation from English to Spanish by two independent certified translators; (2) production of an agreed version by a multidisciplinary committee of experts; (3) back-translation to English of the agreed version by an independent translator; (4) discussion of the semantic, idiomatic, and cultural equivalence of the final version; (5) elaboration of the final test; (6) pilot test on 24 representatives of the autism spectrum disorders population and 24 representatives of typically developing children. The steps were conducted satisfactorily, producing the final version in Spanish, which showed good psychometric properties.

Fusion-optimized intervals (FOI): a new method to achieve the narrowest QRS for optimization of the AV and VV intervals in patients undergoing cardiac resynchronization therapy.

BACKGROUND: Optimization of atrioventricular (AV) and interventricular (VV) intervals may improve cardiac resynchronization therapy (CRT) response but is a complex task. Fusion with intrinsic conduction may increase the benefit of CRT. The aim was to describe fusion-optimized intervals (FOI), a new method of optimizing CRT based on QRS duration. METHODS AND RESULTS: Seventy-six consecutive patients with preserved AV conduction who received CRT were prospectively included. The AV interval was optimized by searching the narrowest QRS obtained within the fusion band during left ventricular (LV) pacing. The VV interval was then adjusted, comparing QRS duration in simultaneous biventricular, LV preexcitation (-30 milliseconds), right ventricular (RV) preexcitation (-30 milliseconds) and LV-only pacing. A substudy in 31 patients evaluated the invasive LV +dP/dtmax . The best fusion-optimized AV interval was 136 ± 30 milliseconds during atrial sensing and 192 ± 35 milliseconds during atrial pacing. The best QRS was obtained with simultaneous biventricular pacing in 28 patients (37%), LV preexcitation in 22 (29%), LV-only in 20 (26%), and RV preexcitation in 6 (8%). Baseline QRS was shortened more by FOI (59 ± 19 milliseconds) than by nominal settings (40 ± 21 milliseconds; P < 0.001). Sixty-five patients (86%) showed >10% shortening of the baseline QRS with FOI; none prolonged the QRS duration by FOI compared to nominal settings. All echocardiographic asynchrony parameters were corrected by FOI. Baseline +dP/dtmax improvement was greater in FOI (127 ± 95 mmHg/seconds) than in nominal settings (102 ± 71 mmHg/seconds; P = 0.05). CONCLUSION: The FOI method is feasible, further reduces QRS duration, and improves acute hemodynamic response compared to nominal programming of CRT.

Catheter ablation of atrial fibrillation in patients at low thrombo-embolic risk: efficacy and safety of a simplified periprocedural anticoagulation strategy.

BACKGROUND: To prevent thrombo-embolic (TE) events during ablation of atrial fibrillation (AF), warfarin is recommended in all patients irrespective of baseline TE risk. We evaluated the efficacy and safety of a simplified periprocedural anticoagulation strategy of aspirin (ASA) and low molecular weight heparin (LMWH) in patients at low TE risk. METHODS: We collected data from 214 low TE risk patients (CHADS2 score ≤1 and no warfarin at baseline) undergoing pulmonary vein isolation. After discontinuation of ASA, periprocedural antithrombotic therapy consisted of therapeutic subcutaneous LMWH injections (nadroparin 1 mL/kg once daily) from 10 days before until 10 days after the procedure, followed by ASA in all patients. At the time of procedure, transesophageal echocardiography (TEE) was not performed on a routine basis. During the procedure, unfractionated heparin was administered to achieve an ACT between 350 and 400 seconds. Data on TE events (stroke or transient ischemic attack), cardiac tamponade/perforation, and major vascular access complications within 3 months after the procedure were collected. RESULTS: Mean CHADS2 was 0.3 ± 0.5. TEE was performed in 3% of patients. No periprocedural TE events occurred. No cardiac tamponade/perforation was observed. Major vascular access complications occurred in 3 patients (1.4%). No permanent injury was observed (0%). CONCLUSION: In selected low TE risk patients undergoing ablation for AF, a short period of periprocedural therapeutic anticoagulation with LMWH together with aspirin is an effective and safe strategy to prevent TE events. If confirmed in a randomized trial, this approach might simplify periprocedural antithrombotic management in ablation of selected AF patients.

Lessons from dissociated pulmonary vein potentials: entry block implies exit block.

AIMS: Prior reports using pacing manoeuvres, demonstrated an up to 42% prevalence of residual pulmonary vein to left atrium (PV-LA) exit conduction after apparent LA-PV entry block. We aimed to determine in a two-centre study the prevalence of residual PV-LA exit conduction in the presence of unambiguously proven entry block and without pacing manoeuvres. METHODS AND RESULTS: Of 378 patients, 132 (35%) exhibited spontaneous pulmonary vein (PV) potentials following circumferential PV isolation guided by three-dimensional mapping and a circular mapping catheter. Pulmonary vein automaticity was regarded as unambiguous proof of LA-PV entry block. We determined the prevalence of spontaneous exit conduction of the spontaneous PV potentials toward the LA. Pulmonary vein automaticity was observed in 171 PVs: 61 right superior PV, 33 right inferior PV, 47 left superior PV, and 30 left inferior PV. Cycle length of the PV automaticity was >1000 ms in all cases. Spontaneous PV-LA exit conduction was observed in one of 171 PVs (0.6%). In a subset of 69 PVs, pacing from within the PV invariably confirmed PVLA exit block. CONCLUSION: Unidirectional block at the LA-PV junction is unusual (0.6%). This observation is supportive of LA-PV entry block as a sufficient electrophysiological endpoint for PV isolation.

Cardiac resynchronization therapy. Indications and contraindications.

Progress in medical therapy wouldn't be possible without the contribution of the scientific community. Several randomized controlled trials have led to our current guidelines. Specifically, COMPANION and CARE-HF trials involved a turning point for cardiac resynchronization therapy, which became well recognized for the treatment of heart failure patients with QRS≥120ms, ejection fraction≤35%, and sinus rhythm to reduce hospitalizations and all-cause mortality. New indications were then established for atrial fibrillation, pacemaker-dependent, and mildly symptomatic patients, but new challenges should be addressed, namely reducing complication and nonresponder rates. To achieve this, further studies and new implant techniques are under investigation.

Value of real-time transesophageal 3-dimensional echocardiography in guiding ablation of isthmus-dependent atrial flutter and pulmonary vein isolation.

In the past decade, both the range of indications and the efficacy and safety of interventional electrophysiology has improved considerably. This progress is attributed to both the accumulating experience of electrophysiologists and the advances in technological tools facilitating the diagnosis and treatment of cardiac arrhythmias. Real-time 3-dimensional transesophageal echocardiography (RT 3D TEE) has emerged as a new imaging tool in the clinical arena. Its ability to image in "real time" cardiac structures "en face" and the almost entire length of intracardiac catheters has made this technique a promising imaging tool to guide percutaneous catheter-based procedures. More recently it has been used in monitoring ablation procedures. In this review, the advantages and current limitations of RT 3D TEE during ablation of cavotricuspid isthmus-dependent atrial flutter and pulmonary vein isolation are described.