End-systolic pressure-volume and end-systolic stress-volume relationships in patients with aortic stenosis and with normal valvular function.

In order to study the effect of left ventricular hypertrophy on the endsystolic pressure-volume relationship, three left ventricular angiograms were performed in ten patients with normal valvular function but with varying left ventricular function (group 1) after 0.15 mg/kg propranolol and 1 mg atropine: at rest, after isosorbide-dinitrate at a decreased afterload and after methoxamine at an enhanced afterload. In eight patients with aortic stenosis (group 2) two left ventricular angiograms were performed: at rest and after isosorbide-dinitrate. Heart rate was kept constant by atrial pacing. Left ventricular mass in group 1 was 89 g/m2 and in group 2 180 g/m2. In group 1 the slope k of the end-systolic pressure-volume relation was related to the ejection fraction (EF) at rest: k = 0.024 . e0.072 EF; r = 0.93. In group 2 this relation was shifted to the left (P less than 0.001): k = 0.135 . e0.057 EF; r = 0.81. The relations, however, between the slope k of the end-systolic stress-volume relation and the ejection fraction were close together in group 1 and in group 2 and crossed at an ejection fraction of 67%. It is concluded: 1. In patients with aortic stenosis the end-systolic pressure-volume relation is steeper than in patients without valvular dysfunction at a given ejection fraction, so the relation between the slope k and the ejection fraction is shifted to the left. 2. The end-systolic stress-volume relationship is not altered in patients with aortic stenosis and seems to be advantageous for the evaluation of left ventricles with substantial hypertrophy due to pressure load.