[Diagnosis by non-invasive methods of incipient left ventricular lesions in patients with Chagas' disease. Use of echocardiography and mechanocardiography].

In this study, ninety-seven patients with positive complement-fixation reaction for Chagas' disease were submitted to M-mode echocardiograms, fonomechanocardiograms, right and left heart catheterization and left cine-ventriculogram, in an attempt to establish the usefulness of these non-invasive methods for the diagnosis of myocardial damage in Chagasic patients. Only the left ventricular end-diastolic volume determination showed a significant echo-angiographic correlation, as well as a satisfactory sensitivity and specificity to detect early myocardial damage. Therefore, with this parameter it was possible to diagnose 33% of patients which had left ventricular cine-angiographic damage, without clinical, electrocardioangiographic or radiological abnormalities. All other non-invasive parameters measured in this study were useful only in patients with advanced myocardial damage, recognizable by abnormal ECG or clinical signs of congestive heart failure. We recommend to obtain good quality left ventricular ecocardiograms in every chagasic patient, particularly those with normal ECG. This will allow the diagnosis of incipient cardiomyopathy in almost one third of all chagasic patients with early left ventricular abnormalities, recognizable by cine-ventriculograms.