Direct measurement of pulmonary and systemic flow during assisted circulation

During biventricular assistance as a bridge to cardiac transplantation, the flow data provided by the pumping systems were compared with flow data obtained with the Fick method. There was a difference between the data sets only in the first 20 hr of observation, with the Fick method giving higher values. During the same period, analysis of the arterial and pulmonary pressure traces showed pulsatile activity to be related with the electrocardiogram's T waves. In the long run, the flow data provided by both methods were no different and the T wave-related pulsatile activity disappeared. The authors concluded that the Fick method represents a useful tool when measuring total flow during biventricular support.