RESUMO
BACKGROUND: Advanced atrioventricular block (AB) during acute myocardial infarction (AMI), characterizes a high-risk subgroup of patients. Our aim was to determine the prognostic significance of AB and its possible peculiarities in relation to infarction localization and/or the thrombolytic therapy. PATIENTS AND METHODS: The prospective study involved 1,239 patients with AMI. We studied clinical characteristics, as well as indexes of infarct size, short and long-term complications. RESULTS: AB was present in 85 (6.8%) patients and was more often associated with: previous treatment with diuretics, diabetes, inferior localisation, higher number of ECG leads with elevated ST segment, and higher peak of CK. The AB was associated with a higher mortality: in-hospital (27% vs 10.6%; p < 0.01)) and after one-year (31.7% vs 19.4%; p < 0.05). Patients with AB had a different in-hospital mortality depending on anterior or inferior infarct localization (66% vs 18.5%; p < 0.001, respectively). In patients receiving thrombolytic treatment (n = 681), the duration of AB was shorter and in-hospital mortality was lower (13.7% vs 47%, p < 0.11) than that occurred in patients without this treatment (n = 558). AB had independent value for predicting in-hospital mortality (OR: 3.56; 95% CI: 1.84-6.90) and one-year mortality (OR: 2.77; 95% CI: 1.52-5.04). CONCLUSIONS: AB is associated with larger infarcts and higher incidence of complications. The prognosis is especially poor when it is presented associated with anterior infarction and/or in patients without thrombolytic treatment. AB is a variable with independent prognostic value on the mortality.
