Cardiac pumping capability and prognosis in heart failure.

In 63 patients with severe acute or chronic heart failure maximum cardiac performance was determined by calculation of the maximum hydraulic power output achieved by the heart during dobutamine challenge. After one year, all but 3 of the 23 patients with maximum cardiac power output (Wmax) less than the normal resting value of 1 W had died of progressive heart failure. Of the 40 with Wmax more than 1 W, all but 4 (who died suddenly) survived longer than one year. Hydraulic power output is a clinically important measure of cardiac pumping performance and a maximum power output value below the normal resting value indicates that long-term survival is unlikely.