Ventricular arrhythmias induced by programmed ventricular stimulation after uncomplicated myocardial infarction.

Abstract

The aim of this study was to correlate the occurrence of ventricular dysrhythmias induced by programmed ventricular stimulation and sudden cardiac death (SCD) after a first episode of acute myocardial infarction (AMI). Twenty-seven consecutive male patients aged fifty-four +/- six (forty-seven to seventy) years were studied prospectively. Thirty days after AMI, patients were submitted to coronary arteriography and programmed ventricular stimulation with the S2-S3-S4 protocol. Noninvasive assessments, including Holter monitoring, ECG stress test, and radionuclide ejection fraction, were also repeated six and twelve months after AMI. Ventricular dysrhythmias were induced in all patients. According to such response, patients were divided into three groups: (1) repetitive ventricular response (n = 9); (2) nonsustained ventricular tachycardia (n = 8); and (3) sustained ventricular tachycardia (n = 10). All patients consistently developed complex ventricular dysrhythmias at Holter monitoring and ECG stress test. One patient from group 2 suffered SCD and another presented a syncope. Similarly, in group 3, 2 patients suffered SCD, 1 during a documented episode of recurrent AMI. Except for 1 patient, radionuclide ejection fraction remained unchanged throughout the study in all cases. SCD was also unrelated to the presence and type of dysrhythmias at noninvasive evaluation. Therefore, the type of ventricular dysrhythmia induced by the S2-S3-S4 protocol has no correlation with late SCD in patients with a first AMI and preserved ejection fraction.