A Catheter Flow Probe for Measurement of Left Ventricular Source Parameters

A balloon-tip electromagnetic velocity flow probe was used to measure source pressure Pg and zero-load aortic flow Qs in seven mongrel dogs before and after coronary artery ligation, where Qs is the expected aortic flow at zero aortic input impedance and Pg is the expected left ventricular pressure for the open-circuit condition of the equivalent model of the left ventricle. The source parameters Pg and Qs were measured by two types of flow probes (cuff-type and catheter-tip flow probe). The source parameters measured by the cuff-type flow probe are designated by Pg and Qs, and Pgv and Vs are source parameters measured by the catheter probe. The correlation coefficient between the mean values of Pg and Pgv was 0.83 in 47 measurements, and correlation between Q5 and Vs was 0.64. After coronary artery ligation, Qs, Pg, Pgj,, and Vs decreased by 35.9, 19.87, 16.67, and 2.6 percent, respectively. A change of 10 to 30 percent in aortic input resistance could be produced by balloon inflation in two consecutive heartbeats. This paper presents a new application of a catheter flow probe for diagnosis of cardiac pump performance during catheterization procedures.