Electrocardiographic abnormalities in elderly Chagas disease patients: a population-based study (the Bambuí study)

Abstract

Introduction: Chagas disease (ChD) is endemic in Latin American countries, but has become a worldwide problem due to migration of infected individuals to developed countries. Electrocardiography has been considered an essential exam to evaluate ChD patients. The objective of this study is to identify prevalent abnormalities in the electrocardiogram (ECG) and common associated conditions in patients with ChD. Methods: In this observational and retrospective study, all 12-lead standard digital ECGs analyzed by cardiologists of a public telemedicine service in Brazil, from January to December 2011 were assessed. This service attends primary care of 660 cities in Minas Gerais province. ECGs were sent by IT professionals in remote sites over the internet to be analyzed centrally by cardiologists who were trained and experienced in the analysis and interpretation of ECGs. The prevalence of ECG abnormalities in patients known to have ChD was assessed. Results: During the study period, 264,324 patients were assessed; 7590 were ChD patients (mean age 57.0 ± 13.7 years, 64.1% women). Hypertension was the most frequent comorbidity (61.3% of the ChD patients), followed by diabetes (9.1%) and dyslipidemia (6.9%). Family history of coronary disease was reported by 32.6% of the patients, and 10.7% were smokers. Only 30.1% of them had normal ECGs. Regarding the rhythm, 86.9% had normal sinus rhythm, 5.3% atrial fibrillation or flutter, 5.4% ventricular premature beats, 2.5% supraventricular premature beats and 3.5% were pacemaker users. Right bundle branch block (RBBB) was observed in 22.7% of the ECGs, left bundle block in 3.1% and left anterior hemiblock (LAH) in 22.5%.The presence of first degree atrioventricular block was found in 4.9%, second and third degrees in 0.2% each. There was electrocardiographic evidence of left ventricular and atrial hypertrophy in 3.6% and 2.5% of patients, respectively. Conclusion: In this large sample of primary care patients with ChD, there was a high prevalence of ECG abnormalities. As expected, the most common abnormalities were RBBB and LAH.