Novel method to estimate ventricular contractility using intraventricular pulse wave velocity

Shishido, Toshiaki, Masaru Sugimachi, Osamu Kawaguchi, Hiroshi Miyano, Toru Kawada, Wataru Matsuura, Yasuhiro Ikeda, and Kenji Sunagawa. Novel method to estimate ventricular contractility using intraventricular pulse wave velocity. Am. J. Physiol. 277 (Heart Circ. Physiol. 46): H2409-H2415, 1999.--We developed a novel technique for estimating ventricular contractility using intraventricular pulse wave velocity (PWV). In eight isolated, cross-circulated canine hearts, we used a fast servo pump to inject a volume pulse into the base of the left ventricular chamber at late diastole and at late systole. We measured the transit time of the volume pulse wave as it traversed the distance from base to apex and calculated the intraventricular PWV. The intraventricular PWV increased from diastole (2.3 [+ or -] 0.4 m/s) to systole (11.7 [+ or -] 2.4 m/s, P [is less than] 0.0001 vs. diastole). The square of the intraventricular PWV at late systole correlated linearly with the left ventricular end-systolic elastance (r = 0.939, P [is less than] 0.0001) and with the end-systolic Young's modulus (r = 0.901, P [is less than] 0.0001). Moreover, the intraventricular PWV was 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 ventricular contractility. cardiac mechanics; ventricular elastance; hemodynamics; muscle properties; stress-strain relationship