Left intraventricular "pseudo-augmentation". A new principle of mechanical assistance

A new technique is described, utilizing an air-driven pump, connected to the left ventricle, without a valve and synchronized with the electrocardiogram. The pump is operated in brief (80 msecs) pulses. When applied at the end-diastolic phase it produces an increase in stroke volume and dp/dt/P and a marked improvement in the function curves of a failing left ventricle, without substantially increasing the mean left atrial pressure. Thus, mechanical assistance to the failing heart can also be based on this new principle, namely the inotropic effect of a brief left intraventricular end-diastolic pseudo-augmentation.