[Mechanism of exercise-induced ST depression based on hemodynamics during cardiac catheterization].

Objectives: The cause of exercise-induced ST depression was studied by assessing left ventricular end-diastolic pressure (LVEDP).

Methods: This study included 28 patients with normal coronary artery, 24 patients with vasospastic angina pectoris and 28 patients with fixed organic lesion who underwent both treadmill exercise testing and selective coronary arteriography. Exercise-induced ST deviation was considered as maximal ST deviation during the exercise test and maximum LVEDP was considered as the pressure measured 1 min after left ventriculography.

Results: The degree of exercise-induced ST depression in aVF showed no significant differences between the three groups. Exercise-induced ST elevation occurred in the intracardiac leads and exercise-induced ST depression occurred in the epicardial leads. These electrocardiographic changes were not contradictory to subendocardial ischemia. In addition, there was a good correlation (r = - 0.465, p < 0.01) between exercise-induced ST depression and maximum LVEDP elevation.

Conclusions: Exercise-induced ST depression was caused by subendocardial ischemia due to increased LVEDP.