A new method for estimating negative dP/dt in patients without valvular regurgitation

pp. 190-197

Abstract

Background

Left ventricle (LV) negative dP/dt (-dP/dt) could be calculated non-invasively only from mitral or aortic regurgitant jet registered with continuous- wave Doppler (CW). 

Purpose

To describe a new method for estimating -dP/dt in patients without valvular regurgitation. 

Material and method

Fourteen patients, (10 male and 4 female [age 61 ± 11]), with ischemic heart disease who underwent cardiac catheterization were included. An hour before the catheterization, we perfomed an Echo-Doppler of the transmital and pulmonary venous (PV) flow, carotid pulse tracing calibrated with the arterial pressure measured with the sphyngomanometer, and peak -dP/dt during catheterization. Mean negative dP/dt was calculated as the slope of pressure fall in LV from end of systole to the mitral valve opening. End systolic pressure was calculated from calibrated carotid pulse tracing. Left atrial pressure (LAP) was assumed as: 10 mmHg if S wave of the PV was greater than D wave, 15 mmg HG if S =D and 20 mmHg if D wave was greater S wave. 

Isovolumic relaxation time (IRT) was measured from aortic closure sound to beginning of transmitral flow (CW) considering that mean -dP/dt = (ESP-LAP) / IRT.

Results

Peak -dP/dt measured at catheterization was correlated with the new method (r = 081, p < 0.001). 

Conclusion

Mean -dP/dt can be estimated non-invasively in patients without valvular regurgitation with the aid of Echo-Doppler transmitral and pulmonary venous flow, comined with calibrated carotid pulse tracing.