Chronic phase of Chagas disease. Clinical aspects and course of the disease

PURPOSE: To evaluate the clinical and evolutive aspects of chronic chagasic patients. METHODS: Three hundred chronic chagasic patients, 180 females, with age ranging from 19 to 81 years (55.6 +/- 13.1) were retrospectively studied. Patients were divided according to the following clinical types: indeterminated, cardiac (with the subtypes: arrhythmogenic, dilated and mixed), digestive isolated and digestive plus cardiac involvement. The following variables were analysed: prevalence of each clinical forms, symptoms, electrocardiographic pattern and clinical outcome. RESULTS: At the start of the study, 73 (24.3%) patients were in indetermined type, 106 (35.3%) in cardiac arrhythmogenic, 95 (31.6%) in mixed, 7 (2.3%) in dilated, 16 (5.3%) in digestive plus cardiac type and 3 (1%) in the pure digestive type. The most prevalent symptoms were dyspnea on efforts (57%), palpitations (41.33%) and chest pain (33%). The most frequent electrocardiographic pattern was right bundle branch block plus antero-superior fascicular block, in 30% of the patients. The average follow-up time was 7.8 +/- 6.1 years and the outcome was considered good in 20 patients (6.6%), stable in 214 (71.3%) and bad in 66 (23%). At the end of the follow-up, 9 patients have evaluated from the indeterminated to the cardiac and digestive types, and 19 (17.92%), from the arrhythmogenic to mixed cardiac subtype. The follow-up was lost in 79 patients (26.3%), most of them, probably dead. CONCLUSION: With a mean time of 7.8 years, 12.3% of the patients in the indeterminated type evolved to the cardiac and/or digestive type; right brundle branch block with antero-superior fascicular block was the most prevalent electrocardiographic pattern; the outcome was stable or good in the majority of these patients.