Análise do perfil clínico de pacientes chagásicos e não-chagásicos portadores de marca-passo cardíaco

Abstract

One of the primary complications of Chagas disease is the damage to the cardiovascular system, causing chronic problems to the myocardium and heart conduction system; other serious complications of this disease are cardiac arrhythmias and sudden death. Comparative studies between Chagas heart disease patients and other types of cardyomyopathies reveal that Chagas patients have worse prognosis. However, appropriate characterization of the functional profile of the Chagas' disease patient who uses a pacemaker is still not well defined. The objective of this transversal study is to compare clinical data, radiological tests, echocardiogram tests, 24 hours Holter monitoring and telemetry data of the pacemaker system in Chagas and non-Chagas patients, all of whom are users of implantable pacemakers We studied 45 Chagas' patients and 35 non-Chagas' patients; all of the 80 patients were users of a cardiac pacemaker, either VVI or DDD, model Affinity ® (St. Jude Medical). In this study, these patients were submitted to a protocol that included clinical history, serology for Chagas' disease, chest X-ray, echocardiograms, 24 hours Holter monitoring and telemetry of the pacemaker system. There wasn't a significant statistical difference among the Chagas' and non- Chagas' patients regarding most of the clinical data, radiological data, and ventricular threshold measurements; even though the Chagas' patients were significantly younger than the non-Chagas' patients (ages 55,9 versus 68,3). The echocardiogram analyses indicated that the Chagas' patients had a greater impairment of the left ventricular systolic function (measured by LV ejection fraction) as compared to non-Chagas' patients. Arrhythmia, detected by the 24 hours Holter recording analyses, was significantly more frequent in the Chagas' patients group (p = 0,013). Data obtained by the echocardiogram and the 24 hours Holter recording analyses showed a direct relationship between low ejection fraction, an important mortality predictor, and the occurrence of ventricular arrhythmias in the Chagas' patients; this association confirms what has been found in medical literature. Conclusion: Our study indicates that Chagas' patients were younger, presented a lower ejection fraction on the echocardiogram, and had a higher incidence of ventricular arrhythmias on the 24 hours Holter recording. A direct correlation between low ventricular ejection fraction and the presence of ventricular arrhythmias on the 24 hours Holter recording was observed.