Características do estudo eletrofisiológico na Doença de Chagas

Abstract

Objective:Chagas disease has become a global problem due to changing migration patterns. An electrophysiological study is generally indicated for assessing sinus node function, conduction through the atrioventricular node and His-Purkinje system, in addition to evaluating the mechanisms of arrhythmia. The aim of this study was to describe the characteristics of electrophysiological study findings in patients with Chagas disease.Methods:A retrospective descriptive study of 115 consecutive patients with Chagas disease undergoing an electrophysiological study over the last three years in a tertiary hospital in Brazil. Baseline characteristics, electrocardiogram, echocardiogram, and 24-hour Holter monitoring findings were recorded and correlated with the electrophysiological study findings.Results:The corrected sinus node recovery time and sinoatrial conduction time were abnormal in 6.9% and 26.1% of patients, respectively. Thirty-seven (32.2%) had abnormal atrioventricular conduction. Intraventricular conduction was abnormal in 39 (33.9%). Approximately 48% had induced sustained ventricular arrhythmias, most of which were monomorphic (83.6%). Right bundle branch block was the most common morphology (52.7%). Fifty-one percent were associated with symptoms/hemodynamic instability, 60% required electrical cardioversion, and 27.3% needed overdrive suppression. The most common site of origin was the left ventricular inferoseptal wall (18.2%), followed by the left ventricular posterobasal wall (11%). Patients with an ejection fraction<40% had a 1.94-fold increased risk of ventricular arrhythmias compared to those with an ejection fraction>60% (OR: 1.94; 95%CI: 1.12-3.38; p=0.01). The presence of complex ventricular arrhythmias on Holter did not predict inducible ventricular arrhythmias.Conclusions:Chagas patients with a low ejection fraction have an increased risk of inducible ventricular arrhythmias. Sinus node dysfunction, and atrioventricular node and His-Purkinje conduction abnormalities occur in about one-third of patients. Complex ventricular arrhythmias on Holter were not associated with an increased risk of inducible ventricular arrhythmias.

Negative association between right bundle branch block and inducibility of ventricular tachyarrhythmias in Chagas disease

“…I read with interest the article by Cedraz et al ( 1 ) describing their findings on the electrophysiological study of 115 chagasic patients. The authors reported that the presence of right bundle branch block (RBBB) was associated with less induction of sustained ventricular tachycardia or ventricular fibrillation (VT/VF) in a univariate analysis.…”

“…Li com interesse o estudo de Cedraz et al, ( 1 ) que descreveram os achados do estudo eletrofisiológico de 115 chagásicos. Os autores demonstraram que a presença do bloqueio do ramo direito (BRD) esteve relacionada a menor indução de taquicardia ventricular sustentada ou fibrilação ventricular (TV/FV) pela análise univariada.…”