Axel Sarrias

New-onset atrial fibrillation after cavotricuspid isthmus ablation: identification of advanced interatrial block is key

AIMS A significant proportion of patients develop atrial fibrillation (AF) following cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFl). The objective of this study was to assess whether the presence of advanced interatrial block (aIAB) was associated with an elevated risk of AF after CTI ablation in patients with typical AFl and no prior history of AF. METHODS AND RESULTS This study included patients with typical AFl and no prior history of AF that were referred for CTI ablation. Patients were excluded when they had received repeat ablations or did not demonstrate a bidirectional block. In all patients, a post-ablation electrocardiogram (ECG) in sinus rhythm was evaluated for the presence of aIAB, defined as a P-wave duration ≥120 ms and biphasic morphology in the inferior leads. New-onset AF was identified from 12-lead ECGs, Holter monitoring, and device interrogations. The cohort comprised 187 patients (age 67 ± 10.7 years; ejection fraction 55.8 ± 11.2%). Advanced interatrial block was detected in 18.2% of patients, and left atrium was larger in patients with aIAB compared with those without aIAB (46.2 ± 5.9 vs. 43.1 ± 6.0 mm; P = 0.01). Over a median follow-up of 24.2 months, 67 patients (35.8%) developed new-onset AF. The incidence of new-onset AF was greater in patients with aIAB compared with those without aIAB (64.7 vs. 29.4%; P < 0.001). After a comprehensive multivariate analysis, aIAB emerged as the strongest predictor of new-onset AF [odds ratio (OR) 4.2, 95% confidence interval (CI): 1.9-9.3; P < 0.001]. CONCLUSION Advanced interatrial block is a key predictor for high risk of new-onset AF after a successful CTI ablation in patients with typical AFl.

Spanish Catheter Ablation Registry. 17th Official Report of the Spanish Society of Cardiology Working Group on Electrophysiology and Arrhythmias (2017)

INTRODUCTION AND OBJECTIVES This report describes the findings of the 2017 Spanish Catheter Ablation Registry. METHODS Data collection was retrospective. A standardized questionnaire was completed by each of the participating centers. RESULTS A total of 15 284 ablation procedures were performed by 98 institutions (the highest number of ablations and institutions historically reported in this registry), with a mean of 156±126 and a median of 136 procedures per center. For the first time, the most frequently treated ablation target was atrial fibrillation (n=3457; 22.6%), followed by cavotricuspid isthmus (n=3449; 22.5%) and atrioventricular nodal re-entrant tachycardia (n=3429; 22.4%). The overall success rate was 87%. The rate of major complications was 2.6%, and the mortality rate was 0.09%. The percentage of procedures performed without fluoroscopic support increased to 6% of all ablations, and 2.3% of all ablations were performed in pediatric patients. CONCLUSIONS The Spanish Ablation Catheter Registry systematically and uninterruptedly collects data on the ablation procedures performed in Spain, revealing that both the number of ablations and the number of centers performing them has progressively increased, while maintaining a high success rate and a low percentage of complications.

Iatrogenic pleuropericardial communication: A rare complication of percutaneous epicardial mapping

Ablation of ventricular tachycardia (VT) is a wellestablished treatment for patients with recurrent implantable cardioverter-defibrillator shocks. Epicardial access is increasingly performed when epicardial arrhythmogenic substrate is suspected and may be considered as a first-line approach in the subset of myocardial diseases with preferential epicardial substrate, namely, idiopathic dilated cardiomyopathy, arrhythmogenic right ventricular dysplasia, or chagasic cardiomyopathy. Cardiac complications of this approach include right ventricular puncture, pericardial bleeding, coronary vessel damage, and pericarditis. Damage to extracardiac structures may occur during puncture, mapping, and ablation; deep knowledge of the anatomic relationships of the heart and prompt recognition of complications are paramount to minimize procedural risk. We report the first case of acute iatrogenic pleuropericardial communication during epicardial mapping in a patient with chagasic cardiomyopathy.

Importance of sudden cardiac death risk stratification in hypertrophic cardiomyopathy. Response.

We are grateful for the comments of Martinez-Moreno et al in relation to our work on the results of implantable cardioverterdefibrillator (ICD) implantation in hypertrophic cardiomyopathy. Whilst it is true that our study was a small series with a relatively short follow-up, we believe that it was representative of the hypertrophic cardiomyopathy population in nonspecialized centers. This nonspecialization would explain the low rate of appropriate therapies compared with that in previous studies, which are from large specialized centers attending patients with the most severe disease. The authors’ observations are appropriate, given the recent publication of the new European Society of Cardiology guidelines on hypertrophic cardiomyopathy, which recommend the use of HCM Risk-SCD, a new tool for evaluating sudden cardiac death risk, which naturally was not used in our cohort when the decision was made on ICD implantation. We calculated this risk a posteriori in the 48 primary prevention patients from our cohort, with the following results: 12 patients (25%) would have had a calculated risk of < 4%, and therefore no indication for ICD implantation according to the new guidelines; 7 patients (14.6%) would have had a risk of between 4% and 6% (class IIb ICD indication), and 29 patients (60.4%) would have had a risk > 6% (class IIa indication). Interestingly, the 3 patients in our cohort who received appropriate therapies would have had a risk of > 6%. Had we applied the new guidelines to our cohort, we would have ‘‘saved’’ ICD implantation in 39.6% of the patients, who, in addition, had received no shocks at the time of follow-up. Also, as noted in the original article, secondary prevention patients have a paradoxically low risk profile, and although HCM Risk-SCD is not valid for secondary prevention, in which ICD implantation has a class I indication, we calculated the risk for our cohort patients, using the data available. All patients would have had a theoretical risk of < 6%, and consequently would have had no indication for ICD prior to their episode of ventricular arrhythmia. We agree that HCM Risk-SCD improves patient selection in those with 1 or more risk factors, but it does not solve the problem that many sudden cardiac deaths occur in patients who are theoretically low risk, and so cannot be identified using tools based on classic risk factors. It surprises us that, in the development of HCM Risk-SCD, there was no evaluation of imaging (such as fibrosis on magnetic resonance), electrophysiological, or genetic parameters, which could help to better identify at risk patients in the future.

Implantable Cardioverter-defibrillator Therapy for Hypertrophic Cardiomyopathy: Usefulness in Primary and Secondary Prevention.

INTRODUCTION AND OBJECTIVES Hypertrophic cardiomyopathy is a frequent cause of sudden death. Clinical practice guidelines indicate defibrillator implantation for primary prevention in patients with 1 or more risk factors and for secondary prevention in patients with a history of aborted sudden death or sustained ventricular arrhythmias. The aim of the present study was to analyze the follow-up of patients who received an implantable defibrillator following the current guidelines in nonreferral centers for this disease. METHODS This retrospective observational study included all patients who underwent defibrillator implantation between January 1996 and December 2012 in 3 centers in the province of Barcelona. RESULTS The study included 69 patients (mean age [standard deviation], 44.8 [17] years; 79.3% men), 48 in primary prevention and 21 in secondary prevention. The mean number of risk factors per patient was 1.8 in the primary prevention group and 0.5 in the secondary prevention group (P=.029). The median follow-up duration was 40.5 months. The appropriate therapy rate was 32.7/100 patient-years in secondary prevention and 1.7/100 patient-years in primary prevention (P<.001). Overall mortality was 10.1%. Implant-related complications were experienced by 8.7% of patients, and 13% had inappropriate defibrillator discharges. CONCLUSIONS In patients with a defibrillator for primary prevention, the appropriate therapy rate is extremely low, indicating the low predictive power of the current risk stratification criteria.

From Atrial Fibrillation to Ventricular Fibrillation and Back

A 27-year-old man without any previously known health conditions was found unresponsive on the street after he had been exercising. Cardiopulmonary resuscitation was started by bystanders. On arrival of the emergency services, the rhythm strip in Figure 1A was recorded. It shows an irregular wide-complex tachycardia with different degrees of QRS widening, consistent with preexcited atrial fibrillation with very fast conduction to the ventricles. At the end of the strip, QRS complexes become smaller and erratic as atrial fibrillation turns into ventricular fibrillation. After 4 direct-current shocks (Figure 1B), the ventricles are defibrillated but preexcited atrial fibrillation persists. It is only after 17 shocks and amiodarone administration (Figure 1C) that sinus rhythm is restored. The patient …