BACKGROUND: The purpose of this study was to assess the incidence, clinicalcourse, prognosis and mean length of stay in acute myocardial infarction (AMI) complicated by high-gradeatrioventricular block (HAVB). MATERIAL/METHODS: A retrospective cohort study including all AMI patientslisted from January 1995 to September 2000 in the ARIAM multi-center register. Univariate analysis wascarried out to study the factors associated with the development of HAVB, the mortality rate, and themean length of stay, and multivariate logistic regression analysis to study whether HAVB is an independentpredictive variable for mortality or prolongation of stay. RESULTS: Of the 14,181 AMI patients includedin the register, 837 (5.9%) presented with HAVB, which was associated with age, female sex, increasedseverity, diabetes, inferior and Q-wave AMIs, and a higher peak creatine phosphokinase (CPK) level. TheHAVB patients developed more complications, required more diagnostic-therapeutic resources, and showedsignificantly higher mortality (p<0.0001) and increased mean length of stay (p<0.0001). The independent risk factors for HAVB were age, maximum peak CPK, inferior or combined localization of the AMI, Q-wave AMI, diabetes, a Killip and Kimball score > 1, and thrombolysis. HAVB was found to be an independent predictive variable for mortality and increased mean length of stay.
Conclusions: AMI patients with HAVB, despite thrombolytic treatment, are at risk for complications, mortality and longer mean admissions. Further study is needed on the outcome of a more active reperfusion policy, such as direct, rescue angioplasty etc.

Keywords: Heart Block, Logistic Models, Multivariate Analysis, Sex Factors, Time Factors