In this longitudinal study 5,710 people were included. The inclusion
criteria were two positive serological results for Trypanosoma cruzi
infection, 15 and 50 years old and no other demostrable diesease at the
time of study. In the five year follow up 1,117 patients were lost. The
follow up involved yearly evaluation of serology, clinical examination,
X-ray of torax, and ECG, for 4,593 patients and 263 were contacted at
home because they did not assist for their clinical consultant. Time
average of follow up was 5.3 years. Eighty nine (1.5%) of the 4,593
patients died during the follow-up period, 63 (71%) by cardiac
insufiency (CI) and 26 (29%) by severe ventricular arrithmias.
Diagnosis of cardiomegaly was present in all the patients with
diagnosis of CI and in 15 (5%) of the patients with diagnosis of
arrithmias.The ECG alterations of these pacients show 61 right bundle
brunch block (RBBB), associated or not with left anterior hemiblock
(LAHB), 47 pathological Q wave and 70 primary repolarization
alterations; 61 had polyfocal ventricular arrithmia. The death rate
was similar in the sexes and was more frequent between 40 and 50 years
of age. Information on 1,380 recuperated patients shows that 15 died
with no previous symptoms and without medical assistance and were
interpretate as sudden death. The latest ECG in three follow-up of
these pacients indicates (before death) that only one had normal study
and 14 presented 12 RBBB; 9 LAHB; 7 isolated ventricular arrithmia; 10
repolariz alterations; 2 patological Q wave, 10 patients of them with
RBBB and repolariz alterations. In all the cases we had people between
35 and 43 years old, 9 men and 6 women. This study shows that in Chagas
disease is possible to differenciate two risk groups. A low risk death
group that have normal ECG and clinical evaluation during the follow
up, and a high risk group associate ECG with RBBB and primary
alterations of repolarization and/or inactivation zones with not anual
clinical evaluation