Clinical considerations of life-saving effect of left ventricular assist device

Abstract

Our left ventricular assist device (LVAD), containing an automatic level control of total systemic flow and left atrial pressure, was clinically applied in 16 patients (aged 3–73 years) with cardiogenic shock following acute myocardial infarction (AMI; nine cases) and cardiac surgery (seven cases). The entire circulation was well maintained at the normal level and the LVAD was successfully removed in nine patients (56%). Three patients (19%) could be discharged with a satisfactory condition. Removal of left ventricular overload with the use of the LVAD prevented overextension of the impaired myocardium, and the gradual increase in left ventricular work promoted the compensatory ability of the residual myocardium. This recovery mechanism was established in chronic animal experiments using goats. However, the clinical problem with the treatment was the preexisting myocardial damage, such as fibrosis caused by rheumatic myocarditis and ischemia in the residual myocardium. In addition, although the natural heart recover, several patients died of multiple organ failure, which had developed during the prolonged low perfusion period prior to left ventricular assistance. In conclusion, the timely use of LVAD proved to be effective in treatment of cardiogenic shock, but preexisting myocardial damage and delayed application will considerably decrease the chance of a favorable recovery in clinical cases.