Role of Flow Propagation Velocity Across Mitral Valve in the Assessment of Diastolic Dysfunction and Prognostication in Acute Myocardial Infarction

Abstract

Background: The importance of left ventricular (LV) systolic dysfunction as a predictor of mortality and morbidity after acute myocardial infarction (MI) is well known. In MI, Doppler echocardiography can be used to determine the LV diastolic function, and a restrictive transmitral flow pattern has been related to the development of congestive heart failure and increased mortality. In patients with various etiologies of LV systolic dysfunction, restrictive filling has also proven to be an independent predictor of adverse outcome. Materials and Methods: 130 patients who presented with diagnosis of acute MI were included. Echocardiography was performed within 24 hours of arrival to the coronary care unit. Most widely used approach for measuring mitral-to-apical flow was used for velocity propagation. Based on the ratio E/Vp, patients divided into two groups with E/Vp <1.5 and E/Vp >1.5. Patients were followed up subsequently. Results: In the study population, the average age of patients was 59 ± 11.6 years. There were 105 male (80.77%) and 25 female patients (19.23%). On evaluation of risk factors, 69 patients (53.08%) were hypertensive, 71 patients (54.62%) were diabetic, 7 patients (5.38%) were smokers, and 43 patients (33.08%) had dyslipidemia. In patients with E/Vp <1.5, 31 patients (73.81%) had Grade I diastolic dysfunction (DD) and 10 patients (23.81%) had Grade II DD. One patient (2.38%) had Grade III DD. In patients with E/Vp >1.5, 20 patients (22.73%) had Grade I DD, 52 patients (59.09%) had Grade II DD and 16 patients (18.18%) had Grade III DD. Conclusion: In this echocardiographic study of 130 patients with MI E/Vp measured with color M mode is easily obtainable and this E/Vp is a strong predictor of heart failure and mortality. The ratio of peak E wave velocity to flow propagation velocity can be used with other diastolic function variables in predicting outcome. Furthermore, these Doppler variables may be used as simple tools to rapidly risk stratify patients with acute MI.