A Novel Noninvasive Method to Assess Left Ventricular −dP/dt Using Diastolic Blood Pressure and Isovolumic Relaxation Time

BACKGROUND: Left ventricular Doppler-derived -dP/dt determined from the continuous-wave Doppler spectrum of the mitral regurgitation (MR) jet has been shown to be a valuable marker of diastolic function, but requires the presence of MR for its assessment. We sought to determine if a novel method of determining -dP/dt using the diastolic blood pressure and isovolumic relaxation time (DBP-IVRT method) correlates with Doppler-derived -dP/dt using the MR method (Doppler-MR method). METHODS: Thirty-three patients with less than severe MR were enrolled. -dP/dt was determined using the Doppler-MR method from the continuous-wave Doppler spectrum of the MR jet (32 mmHg/time from 3 to 1 m/sec). -dP/dt was also determined using the DBP-IVRT method using the following equation: -dP/dt = (DBP - LVEDP)/IVRT, where left ventricular end-diastolic pressure (LVEDP) was estimated based on tissue Doppler and mitral inflow patterns. RESULTS: Twenty-five patients had adequate Doppler waveforms for analysis. The average amount of MR was mild-to-moderate severity. The mean -dP/dt was 680 ± 201 mmHg by the Doppler-MR method and 681 ± 237 mmHg by the DBP-IVRT method. There was a significant correlation between the 2 methods of determining -dP/dt (Pearson r = 0.574, P = 0.003). The Bland-Altman plot revealed almost no bias between the 2 methods; the difference in -dP/dt between the 2 techniques was noted to be greater for patients with higher -dP/dt, however. CONCLUSION: Diastolic blood pressure and isovolumic relaxation time may be used to noninvasively assess diastolic function in patients who do not have MR, especially in those with reduced diastolic function.