The pacing stress test has been shown to be useful in evaluating the severity and extent of coronary insufficiency in patients with a history of ischemic heart disease. Inducing an increase in heart rate by stimulating the right atrium via an electrode catheter an elevation of the left ventricular filling pressure and ischemic ECG changes could be observed often preceding the onset of anginal pain (Friesinger et al.;Pitt et al.;). Assuming that also in patients with aortic valvular disease the pacing stress test might prove helpful in assessing the coronary reserve and thus the surgical risk, the right atrium was stimulated with an increasing rate. It could be observed however, that in spite of a history of angina pectoris and coronary insufficiency the 9 patients with severe aortic stenosis as well as those 7 of the control group without any left ventricular pressure load showed a decrease and no increase in left ventricular enddiastolic pressure with higher rates. Only in one instance precordial pain occurred without the corresponding hemodynamic changes. - Systolic left ventricular pressure dropped in the patients with aortic stenosis, whereas it stayed constant or even increased slightly in the control group. - The rate of pressure rise (d P/dt) remained about constant in the patients with aortic stenosis, while an increase in this parameter up to 50% above the initial values resulted in the control group. - In both patient groups with the rising rate of stimulation the P-R interval was prolonged. According to these results the pacing stress test does not permit to demonstrate the coronary insufficiency by hemodynamic criteria that must be assumed to exist for anamnestic and pathological-anatomical reasons in patients with severe valvular aortic stenosis. - The possible causes for these unexspected findings are discussed. © 1969 Springer-Verlag.
