Value of left ventricular ejection fraction in extensive anterior infarction to predict development of ventricular tachycardia.

In 33 patients admitted with an extensive acute anterior myocardial infarction (MI), left ventricular ejection fraction (LVEF) was determined within 1 week after MI using radionuclide angiography. In 15 patients, sustained ventricular tachycardia (VT) developed in the second and third week after MI. Thirteen of the 15 patients had an LVEF less than 40%. Only 3 of 18 patients who did not develop late VT had an LVEF less than 40%. Of the 15 patients who developed VT, 8 had right bundle branch block within 48 hours after the onset of chest pain. Right bundle branch block was seen in only 3 of the 18 patients who did not develop VT. We conclude that in patients with extensive anterior MI, a radionuclide LVEF of less than 40% identifies a group at high risk of developing VT within a few weeks after MI.