Novel method to estimate ventricular contractility using intraventricular pulse wave velocity

We developed a novel technique for estimating ventricular contractility usi ng intraventricular pulse wave velocity (PWV). In eight isolated, cross-cir culated canine hearts, we used a fast servo pump to inject a volume pulse i nto the base of the left ventricular chamber at late diastole and at late s ystole. We measured the transit time of the volume pulse wave as it travers ed the distance from base to apex and calculated the intraventricular PWV. The intraventricular PWV increased from diastole (2.3 +/- 0.4 m/s) to systo le (11.7 +/- 2.4 m/s, P < 0.0001 vs. diastole). The square of the intravent ricular PWV at late systole correlated linearly with the left ventricular e nd-systolic elastance (r = 0.939, P < 0.0001) and with the end-systolic You ng's modulus (r = 0.901, P < 0.0001). Moreover, the intraventricular PWV wa s insensitive to preload. We conclude that the intraventricular PWV at late systole reflects left ventricular end-systolic elastance reasonably well. The fact that estimation of PWV does not require volume measurement or load manipulation makes this technique an attractive means of assessing ventric ular contractility.