RESUMO
To show the incidence of second degree Auriculoventricular block (AVB) with Wenckebach phenomenon (WF) 1336 patients with acute myocardial Infarction (AMI) were studied. We found 67 cases with WF 5.0% from the total group of AMI and the 33.83% form the group with any type of AVB. Fifty three were male and 14 female (4:1). 77.5% arrived to ICU for their first AMI and 22.38% for their second AMI. 43.26% were posteroinferior with extension to right ventricule; 36.0% pare posteroinferior, 10.4% anterolateral; 9.0% posterolaterals and 1.4% lateral. The onset time of WF in relation to the AMI set was 64.2% in the first 24 hours; and 17.9% for the 24-48 hour group as well as for those over 48 hours. The duration of the WF in 43.3% was lees than 24 hours 19.4%; between 24-48 hours; 25.4% more than 48 hours and 11.9% was transient. The WF was always present with heart rate under 110x'. In 9 patients it occurred with sinus bradycardia with a 48 to 40x' heart rate. The QRS duration was from 80 to 90 msec in 91.0% and from 100 to 120 msec in 9.0%; 4.47% of them had right bundle branch block previous to WF. 10.4% had progression to Mobitz II and 11.9% lead to complete AVB. Mortality was the 2.98% in the group their first AMI; and 4.47% in the group with their second AMI.