The relationship of ventricular arrhythmias to the angiographically and scintigraphically estimated extent of ventricular damage late after myocardial infarction.

In order to study the quantitative relationship of ventricular arrhythmias to myocardial damage and ischemia, 61 patients with a previous myocardial infarction (at least 6 months previously) were studied by 24-hour ambulatory ECG monitoring, cardiac catheterization, and thallium-201 scintigraphy. Thirty-five patients (57%) had no ectopic beats or only infrequent, unifocal ones and 26 patients (43%) had complex ventricular arrhythmias. Left ventricular function was lower in the latter (p less than 0.05), but the number of diseased vessels did not differ in the two groups. The reduction of thallium activity in the infarct area was more marked in patients with complex arrhythmias (p less than 0.001). Multiple thallium defects were not more common in arrhythmia patients, however. These data support the view that complex ventricular arrhythmias are more closely related to the severity of ventricular damage than the presence of myocardial ischemia remote to the area of previous infarction.