Significance of atrial fibrillation as a precursor of embolism

all levels of ST elevation had inducible ventricular tachycardia. This retrospective analysis of patients who had had an anterior wall acute myocardial infarction failed to demonstrate by clinical electrophysiologic testing any distinguishing characteristics of patients with persistence of ST elevation for at least 2 weeks. Patients were equally vulnerable to programmed stimulation irrespective of the presence or magnitude of this finding. The patients studied were highly selected. In 27 of the 36, sudden death or sustained ventricular tachycardia led to the study. Thus, individuals with anterior wall infarction without such rhythm disturbances are underrepresented. Nevertheless, it is unlikely that absence of ST elevation identifies a group with reduced vulnerability to the initiation of ventricular tachycardia during programmed stimulation because in 8 of 13 such individuals that arrhythmia was induced by means of the protocol used. Had all patients undergone testing free of antiarrhythmic drug treatment, some of the 8 who were not inducible while receiving drugs would have been vulnerable to programmed stimulation. Because such patients were equally represented at all levels of ST elevation, it is unlikely that the conclusions of this study would have been altered. Of 6 patients with right bundle branch block, only 1 had ST elevation >l mm. Repolarization abnormalities secondary to the bundle branch block offset what might have been persistent ST elevation. Exclusion of these patients does not, however, unmask a difference. Ventricular tachycardia was induced in 4 of the 6. Thus, clinical electrophysiologic testing does not identify a basis for persistence of ST elevation after healing of a myocardial infarction. Additional hypotheses must be proposed and tested.