Mechanic Circulatory Support Using Systems with Pulsatile and Non-Pulsatile Flow

pp 503-510

Abstract

Background

Cardiogenic shock is a clinical status with high hospital mortality. This clinical emergency may be secondary toan acute episode of chronic heart failure decompensation or to a catastrophe after cardiac surgery.

Method

This retrospective study reports the use of pulsatile and non-pulsatile flows in two groups of patients with cardiogenic shock. In the first group, a pulsatile flow system was used in nine patients with acute chronic heart failure decompensation as a bridge for heart transplantation. The second group is formed by 79 patients who were supported with non-pulsatile flow systems for ventricular failure post-cardiotomy.

Results

From 1991 through 1993 nine patients were supported with an implantable left ventricular device with pulsatile flow (Heart Mate device) as a bridge for heart transplantation. The mean cardiac index value was 1.7 1/m2 before support and 3.3 1/m2 before transplantation. Similar improvements were obtained with right ventricular ejection fraction from 20% to 38%. Two patients died due to sepsis and multiple organ failure respectively. Five' patients were supported for a mean time of 46 days (22 to 76 days) before heart transplantation. From 1979 through 1991, 79 patients were supported with centrifugal mechanical ventricular assist and non-pulsatile flow after postcardiotomy ventricular failure. Forty nine patients (62%) were successfully weaned and 20 (25.3%) survived the in-hospital phase. We obtained better results with left ventricular support. The mean assistance time was 3.56 days. Morbidity associated with the use of centrifugal pumps were: bleeding (87.3%), renal failure (46.8%), stroke (12.7%), embolism (12.7%) and hepatic failure (12.7%). The survival rate for 7 patients was 70.4% for a mean follow-up of 45.4 months (range2-142).

Conclusions

a) It is possible to perform circulatory support in cardiogenic shock with reasonable results. b) Patients with cardiogenic shock are supported with non-pulsatile flow for the first 48 hours in order to stabilize their hemodynamic condition and then switched to pulsatile flow system as a bridge for heart transplantation.