Difference of late potentials detected by signal-averaged ECG in patients with spontaneous or drug-induced type 1 electrocardiogram pattern of Brugada syndrome

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017.Introduction: Brugada syndrome (BrS) patients (pts) with spontaneous type 1 electrocardiographic (ECG) pattern (sT1ECGp) have a greater arrhythmic risk compared to those with fleicainide-induced type 1 ECG pattern (iT1ECGp). However, when the analysis is restricted to asymptomatic pts, the type 1 spontaneous pattern loses its independent prognostic value. Late potentials (LP) obtained by signal-averaged ECG (SA-ECG) are associated with regions of delayed myocardial depolarization and consequent abnormal electrical conduction. There is a higher prevalence of LP obtained by SA-ECG in pts with BrS and their detection showed a strong prognostic predictor value in several studies. Objective: To evaluate the presence of LP by SA-ECG in pts with BrS and assess differences between patients with spontaneous or drug-induced type 1 ECG pattern. Methods: This was a single-center prospective study of consecutive pts diagnosed with BrS, including sT1ECGp and iT1ECGp. The patients were submitted to SA-ECG study to detect LP, with determination of the duration of filtered QRS (fQRS), root-mean-square voltage of the terminal 40ms of the filtered QRS (RMS40) and the duration of low-amplitude signal (<40 μV) in the terminal part of the filtered QRS complex (LAS40), using conventional and right modified leads. The presence of LP was considered positive when ≥2 of the following were present: fQRS ≥114 ms, RMS40 <20 μV or LAS40 ≥38ms. The results were displayed using medians and interquartile ranges, obtained using the Mann-Whitney test. Results: The presence of LP by SA-ECG was studied in 29 pts (75.9% male, mean age 44±12 years), 18 with sT1ECGp and 11 iT1ECGp. Only 3 pts (10.3%) had symptoms related with BrS (unexplained syncope) and none had documented malignant ventricular arrhythmias. Known or potential pathogenic mutations were identified in 5 pts (17.2%). The presence or absence of LP showed no statistically significant difference according to clinical, electrocardiographic or genetic characteristics of the pts. However, in conventional leads, pts with sT1ECGp showed significantly higher values of fQRS and lower values of RMS40 [fQRS 108 (103–112) vs. 97 (89–103), p=0.016; RMS40 19 (10–22) vs. 22 (16–40), p=0.028]. In addition, in modified right leads, pts with sT1ECGp had significantly higher values of fQRS, lower RMS40 and longer LAS40 [fQRS 108 (101 -111) vs. 98 (89–102), p=0.0005; RMS40 15 (11–21) vs. 25 (18–33), p=0.007; LAS40 41 (34–49) vs. 31 (28- 39), p=0.007]. Conclusion: Patients with the spontaneous type 1 electrocardiographic (ECG) pattern revealed a higher detection of late potentials, which may partially explain the higher arrhythmogenic risk classically described in this subgroup of BrS patients.info:eu-repo/semantics/publishedVersio

Electroanatomic characterization and ablation of scar-related isthmus sites supporting perimitral flutter

Objectives The authors reviewed 3-dimensional electroanatomic maps of perimitral flutter to identify scar-related isthmuses and determine their effectiveness as ablation sites. Background Perimitral flutter is usually treated by linear ablation between the left lower pulmonary vein and mitral annulus. Conduction block can be difficult to achieve, and recurrences are common. Methods Patients undergoing atrial tachycardia ablation using CARTO3 (Biosense Webster Inc., Irvine, California) were screened from 4 centers. Patients with confirmed perimitral flutter were reviewed for the presence of scar-related isthmuses by using CARTO3 with the ConfiDense and Ripple Mapping modules. Results Confirmed perimitral flutter was identified in 28 patients (age 65.2 ± 8.1 years), of whom 26 patients had prior atrial fibrillation ablation. Scar-related isthmus ablation was performed in 12 of 28 patients. Perimitral flutter was terminated in all following correct identification of a scar-related isthmus using ripple mapping. The mean scar voltage threshold was 0.11 ± 0.05 mV. The mean width of scar-related isthmuses was 8.9 ± 3.5 mm with a conduction speed of 31.8 ± 5.5 cm/s compared to that of normal left atrium of 71.2 ± 21.5 cm/s (p < 0.0001). Empirical, anatomic ablation was performed in 16 of 28, with termination in 10 of 16 (63%; p = 0.027). Significantly less ablation was required for critical isthmus ablation compared to empirical linear lesions (11.4 ± 5.3 min vs. 26.2 ± 17.1 min; p = 0.0004). All 16 cases of anatomic ablation were reviewed with ripple mapping, and 63% had scar-related isthmus. Conclusions Perimitral flutter is usually easy to diagnose but can be difficult to ablate. Ripple mapping is highly effective at locating the critical isthmus maintaining the tachycardia and avoiding anatomic ablation lines. This approach has a higher termination rate with less radiofrequency ablation required

A Primary Prevention Clinical Risk Score Model for Patients With Brugada Syndrome (BRUGADA-RISK)

OBJECTIVES: The goal of this study was to develop a risk score model for patients with Brugada syndrome (BrS). BACKGROUND: Risk stratification in BrS is a significant challenge due to the low event rates and conflicting evidence. METHODS: A multicenter international cohort of patients with BrS and no previous cardiac arrest was used to evaluate the role of 16 proposed clinical or electrocardiogram (ECG) markers in predicting ventricular arrhythmias (VAs)/sudden cardiac death (SCD) during follow-up. Predictive markers were incorporated into a risk score model, and this model was validated by using out-of-sample cross-validation. RESULTS: A total of 1,110 patients with BrS from 16 centers in 8 countries were included (mean age 51.8 ± 13.6 years; 71.8% male). Median follow-up was 5.33 years; 114 patients had VA/SCD (10.3%) with an annual event rate of 1.5%. Of the 16 proposed risk factors, probable arrhythmia-related syncope (hazard ratio [HR]: 3.71; p < 0.001), spontaneous type 1 ECG (HR: 3.80; p < 0.001), early repolarization (HR: 3.42; p < 0.001), and a type 1 Brugada ECG pattern in peripheral leads (HR: 2.33; p < 0.001) were associated with a higher risk of VA/SCD. A risk score model incorporating these factors revealed a sensitivity of 71.2% (95% confidence interval: 61.5% to 84.6%) and a specificity of 80.2% (95% confidence interval: 75.7% to 82.3%) in predicting VA/SCD at 5 years. Calibration plots showed a mean prediction error of 1.2%. The model was effectively validated by using out-of-sample cross-validation according to country. CONCLUSIONS: This multicenter study identified 4 risk factors for VA/SCD in a primary prevention BrS population. A risk score model was generated to quantify risk of VA/SCD in BrS and inform implantable cardioverter-defibrillator prescription

A prospective survey in European Society of Cardiology member countries of atrial fibrillation management: baseline results of EURO bservational Research Programme Atrial Fibrillation (EORP-AF) Pilot General Registry

Aims: Given the advances in atrial fibrillation (AF) management and the availability of new European Society of Cardiology (ESC) guidelines, there is a need for the systematic collection of contemporary data regarding the management and treatment of AF in ESC member countries. Methods and results: We conducted a registry of consecutive in- and outpatients with AF presenting to cardiologists in nine participating ESC countries. All patients with an ECG-documented diagnosis of AF confirmed in the year prior to enrolment were eligible. We enroled a total of 3119 patients from February 2012 to March 2013, with full data on clinical subtype available for 3049 patients (40.4% female; mean age 68.8 years). Common comorbidities were hypertension, coronary disease, and heart failure. Lone AF was present in only 3.9% (122 patients). Asymptomatic AF was common, particularly among those with permanent AF. Amiodarone was the most common antiarrhythmic agent used (~20%), while beta-blockers and digoxin were the most used rate control drugs. Oral anticoagulants (OACs) were used in 80% overall, most often vitamin K antagonists (71.6%), with novel OACs being used in 8.4%. Other antithrombotics (mostly antiplatelet therapy, especially aspirin) were still used in one-third of the patients, and no antithrombotic treatment in only 4.8%. Oral anticoagulants were used in 56.4% of CHA 2DS2-VASc = 0, with 26.3% having no antithrombotic therapy. A high HAS-BLED score was not used to exclude OAC use, but there was a trend towards more aspirin use in the presence of a high HAS-BLED score. Conclusion: The EURObservational Research Programme Atrial Fibrillation (EORP-AF) Pilot Registry has provided systematic collection of contemporary data regarding the management and treatment of AF by cardiologists in ESC member countries. Oral anticoagulant use has increased, but novel OAC use was still low. Compliance with the treatment guidelines for patients with the lowest and higher stroke risk scores remains suboptimal. © The Author 2013