[ECG changes during the exercise test and perfusion pressure in the basin of the left coronary artery].

Variation in cumulative electrocardiographic depolarization (delta epsilon QRS) and repolarization (delta epsilon T and ST depression below 1 mm and more) parameters at threshold stress, achieved by stepwise augmentation, was compared with perfusion pressure in the left coronary arterial network, measured at coronaro-angiography, in 103 coronary patients. It is concluded that changes in cumulative ECG parameters at threshold stress can only be suggestive of a possible drop in perfusion pressure in the left coronary arterial network.