Revascularization After Acute Myocardial Infarction Hooshang Bolooki, MD, FRCS(C),
\s=b\ Revascularization of the myocardium was performed in 25 patients two to eight hours after acute myocardial infarction (Ml). The intra-aortic balloon pump was used in 11 patients. Thirteen patients received revascularization within four hours of onset of Ml; all survived the operation. Seven patients were studied postoperatively; ten of 12 grafts (83%) were patent. There was a considerable decrease in left ventricular (LV) dyskinesis and an improvement in LV function. Among 12 patients in whom revascularization was performed for more than four hours' duration
after the onset of Ml, ten survived. Six were studied postoperasix of nine grafts (66%) were patent. There was an increase in LV dyskinesis, with deterioration in LV function. In three patients, ECG evidence of Q wave persisted in spite of absence of dyskinesis postoperatively. The interval during which revascularization of acute infarction produces acceptable results in less than four hours.
(Arch Surg 111:1216-1224, 1976) from this1- and other institutions' have indicated an improvement in left ventricular and a decrease in the extent of eventual myocardial infarction (MI) when reperfusion of the area of infarct was accomplished within two to three hours. These experimental studies were supported by a series of clinical reports" indicating the possibility of decrease in the extent of the eventual area of LV dyskinesis (infarction) by early revascularization. Assessing the safe period during which myocardial revascularization could be performed in patients with an improvement in LV func¬ tion, and possibly a decrease in the extent of infarction, comprises the purpose of this study.
reports Previ o us (LV) performance
SUBJECTS AND METHODS
Twenty-five patients were studied, six women and 19 men, 26 to 66 years of age (median, 50 years), who were treated in the early stages of acute MI (Tables 1 and 2). These 25 patients were among 130 patients who were admitted with the diagnosis of preinfarction angina or intermediate coronary syndrome and who at some time in the course of initial treatment or during preoperative cardiac catheterization studies developed MI. Myocardial infarc¬ tion involved the anterior or anteroseptal wall in 21 of these patients, the posterior or inferior wall in three, and the lateral wall
Criteria for Diagnosis of Acute Ml Since all these patients were admitted to the hospital with a diagnosis of preinfarction angina and were cared for in a coronary care unit, daily serum enzyme studies, 12-lead ECGs, and hourly ECG tracings were available for each patient. Diagnosis of acute MI was effected on the basis of the following criteria: (1) development of a prolonged episode of chest pain (longer than 30 minutes) in association with ECG changes of ischemia in the form of sustained ST-segment elevation (Fig 1) or inverted waves; (2) acute changes in ECG, with development of Q waves (Fig 2) pre¬ operatively or during induction; (3) deterioration of clinical status, with hypotension (blood pressure