In the period from September 1976 to 1977, aortic or mitral valve replacement was performed in 84 and 34 patients respectively. Cardiogenic shock occurred during or immediately after the operation in 3 and 2 patients respectively (= 8.8% and 2.4%). In spite of the use of intra-aortal counter-pulsation, none of the patients survived the acute event. During the same period, 8 (= 5%) out of 113 patients who had undergone coronary surgery needed intra-aortal counter-pulsation. 4 of them survived the acute left heart failure and at the present time are clinically healthy (N.Y. Heart Association Class II).