RESUMEN
BACKGROUND: Brugada syndrome (BrS) is associated with abnormal electrophysiological properties at right ventricular epicardium, consisting of fragmented electrograms extending well beyond QRS termination. We aimed to evaluate the utility of signal-averaged electrocardiogram (SA-ECG) for the noninvasive assessment of late potentials (LP) and risk stratification of BrS patients. METHODS: A prospective, observational, single-center study of BrS patients is submitted to SA-ECG with the determination of the total filtered QRS duration (fQRS), root mean square voltage of the 40 ms terminal portion of the QRS (RMS40), and duration of the low-amplitude electric potential component of the terminal portion of the QRS (LAS40). LP were considered positive when above standard cut-offs: fQRS > 114 ms, RMS40 < 20 µV, and LAS40 > 38 ms. The rates of malignant arrhythmic events (MAEs), defined as sudden death or appropriate shocks, were compared in relation to clinical characteristics and SA-ECG findings. RESULTS: A total of 106 BrS patients (mean age, 48 ± 12 years, 67.9% male) were studied, 49% with type-1 spontaneous pattern and 81% asymptomatic. During a median follow up of 4.7 years, 10 patients (7.1%) suffered MAEs, including 4 sudden deaths. The presence of LP was significantly associated with the arrhythmic risk, which increased with the number of altered LP criteria. In comparison to the patients who had none or 1 altered LP criterium, MAE risk was 4.7 times higher in those with 2 altered criteria and 9.4 times higher in those with 3 altered LP criteria. CONCLUSIONS: SA-ECG may be a useful tool for risk stratification in BrS. The presence of 2 or 3 abnormal LP criteria could identify a subset of asymptomatic patients at high risk of arrhythmic events.
RESUMEN
Opportunistic screening for atrial fibrillation (AF) is currently recommended for patients aged 65 years and older. However, this has recently been called into question by two studies that report that opportunistic screening is no more effective than usual care. Furthermore, there seems to be no consensus on which is the most effective screening strategy (opportunistic or systematic). Thus, we aimed to compare the different AF detection strategies with each other using the methodology of systematic review with network meta-analysis. An electronic database search of MEDLINE, CENTRAL, and EMBASE was performed. In addition, we also searched OpenGrey, experts' knowledge and screened the reference list of included studies or other relevant publications. The search was performed on the 2nd of November of 2020 and updated on the 20th of September of 2021. We performed a random-effects pairwise meta-analysis and a random-effects network meta-analysis within a frequentist framework in an intention to screen analysis. We reported the results as relative risk (RR) with 95% confidence intervals (CI). We assessed the confidence in the evidence using the GRADE framework. Nine studies were included, enrolling 80,665 participants. Pooled effect sizes suggested that systematic screening was effective when compared with usual care (RR 2.11; 95% CI 1.48-3.02; high GRADE confidence) and when compared with opportunistic screening (RR 1.86; CI 1.23-2.82; high GRADE confidence) but no significant difference was found between opportunistic screening and usual care (RR 1.13; 95% CI 0.79-1.63; low GRADE confidence). Systematic screening was the most effective strategy for detecting atrial fibrillation in individuals aged 65 years or older. Opportunistic screening was no more effective than usual care, but the results were weakened by a low quality of evidence due to risk of bias of the included studies and imprecision in the results. PROSPERO registration number: CRD42020218672.
