How to Identify Latent Systolic Dysfunction and Post Operative Risk in Patients with Mitral Incompetence and Normal Ejection Fraction?

摘要

Purpose: To study the significance of impaired positive peak rate of left ventricular (LV) pressure development (MR + dp/dt) and global systolic strain (GLPSS) values in patients presented with significant mitral incompetence (MR) in coronary artery disease (CAD) and early dilated cardiomyopathy (DCM) with normal ejection fraction (EF). Methods: A description of LV contractile behavior requires measurement of the ability of the ventricle to develop force (pressure) and to shorten. Hence, performance of the ventricle as a pump assessed in the present study by measuring the pressure developed by the ventricle (Left ventricular +dP/dt is estimated from MR jet as the rate of pressure rise from 1 to 3 m/sec) and shortening assessed by GLPSS (this Doppler technology allowed measurement of LV systolic strain for the entire length of LV myocardium). GLPSS and MR + dp/dt were calculated in 30 consecutive patients (mean age was 55 ± 12 years) characterized by echocardiographic evidence of moderate or severe MR (in CAD and DCM patients) and normal EF (mean LV Ejection Fraction of 50.9% ± 5.9%) and compared with those obtained in 35 consecutive controls (age 54.7 ± 11.4 years) with normal echocardiographic study of the heart. Results: The mean values of MR +dp/dt and GLPSS averaged from the 3 apical views, differed significantly in DCM and CAD patients (characterized by significant MR with normal EF) compared with control group, (MR + dp/dt = 733 ± 170 mmhg/s and GLPSS –13% ± 1.3%) versus (1420 ± 210 mmhg/s and -19.5% ± 3.3%) for patients versus control, respectively, p < 0.001. A depressed values of MR + dp/dt were highly correlated with GLPSS values in patients with CAD and DCM, r = 0.78. The combined use of 2D Strain (<-13%) and MR dp/dt (<900 mmhg/s) in the presence of MR (grade II or more) had 89% sensitivity and 92% specificity for detection of patients at risk of post-operative major cardiac events after MR and coronary artery bypass surgery. Conclusions: Latent LV systolic dysfunction could be defined noninvasively by depressed peak MR + dp/dt and GLPSS in the echocardiography laboratories.