ADAPTATION TO MYOCARDIAL-ISCHEMIA DURING CORONARY ANGIOPLASTY DEMONSTRATED BY CLINICAL, ELECTROCARDIOGRAPHIC, ECHOCARDIOGRAPHIC, AND METABOLIC PARAMETERS

It has been shown that brief episodes of myocardial ischemia can rende r the heart more resistant to a prolonged subsequent ischemic episode. This phenomenon, called ''preconditioning,'' has been described in hu man beings during coronary angioplasty with the use of clinical, elect rocardiographic (EGG), or metabolic parameters. The goal of this study was to assess this phenomenon further with the use of echocardiograph ic and metabolic parameters in addition to clinical and ECG parameters . Eighteen patients with isolated stenosis of the left anterior descen ding coronary artery and a normal left ventricular function were inclu ded. Angioplasty consisted of four consecutive balloon inflations. Seq uential changes in clinical, ECG (intracoronary EGG), echocardiographi c, and metabolic parameters of myocardial ischemia were compared betwe en the first and the fourth balloon inflations. Improved tolerance to myocardial ischemia with repeated coronary occlusions was demonstrated by a significant reduction in the severity of angina, ST-segment elev ation, wall motion abnormalities, and lactate production. This study c onfirms the adaptation of myocardial ischemia to repeated coronary occ lusions through measurement of clinical, EGG, echocardiographic, and m etabolic parameters.