EXERCISE-INDUCED QRS DURATION CHANGES IN PATIENTS WITH CORONARY-ARTERY DISEASE-APPEARING WALKTHROUGH ANGINA

Two patients with coronary artery disease appearing as ''walkthrough'' angina underwent a treadmill exercise test. During the exercise, the patients appeared to have anginal pain associated with ST-segment depr ession and increased QRS duration. As the patients continued walking, anginal pain disappeared and a concomitant lessening in ST-segment dep ression and QRS prolongation was observed. Thus, the fact that the ons et of angina was associated with ST-segment depression and prolonged Q RS duration, while the disappearance of angina was associated with a d ecrease in ST-segment depression and QRS prolongation, is indicative o f the effect of exercise-induced myocardial ischemia on QRS duration.