Arrhythmias and Left Ventricular Functions in Patients with Acute Myocardial Infarction and bundie Branch Block

Arrhythmias and left ventricular functions were investigated in 40 patients having transmural acute myocardial infarction (AMI) and bundle branch block (BBB) with 24-hr Holter-monitoring and echocardiography. Asa control group, 144 patients with AMI but without BBB were evaluated during the inhospital phase, and 45 of them were followed up for an average of 15 months. In the hospital phase, although 32 percent of the patients with BBB had complicated arrhythmias (multiform, paired VPC, runs, R on T) 10 of the 13 patients who died did so from pump failure. During the follow-up period there was no significant difference between patients with BBB and without in regard to complicated arrhythmias (14.8% vs 15.6 %). In patients with BBB the wall motion index and the proportion who had a left ventricular aneurysm were greater than patients with BBB (9.5±0.9 vs 6.3±0.6, p<0.01 and 52.0 o/o vs 14.3 %, p<0.01, respectively). Hence, 1) Left ventricular dysfunction in patients with AMI and BBB is greater than in patients with AMI unaccompanied by BBB. 2) The frequency of complicated arrhythmias was not significantly different between the two groups.