Assessment of Transmitral Vortex Formation in Patients with Diastolic Dysfunction

Abstract

Previous experimental models have related transmitral vortex formation to the longitudinal recoil of left ventricle. However, little is known about the relationships among left ventricular (LV) longitudinal relaxation, transmitral filling patterns, and LV vortex formation in clinical settings. The aim of this study was to compare the vortex formation time index among a heterogeneous group of patients with diastolic dysfunction to understand the relationship between transmitral vortex formation and abnormal diastolic filling patterns. Echocardiographic data from 107 subjects were retrospectively evaluated. The study population was categorized into four groups on the basis of transmitral early and late diastolic Doppler filling patterns as normal (n = 45), impaired relaxation (n = 14), pseudonormal (n = 26), and restrictive (n = 22). Vortex formation time was computed from the governing equations based on transmitral flow and ejection fraction. Differences in vortex formation time index were found to be significant among all the studied groups (P < .0001). The trend of vortex formation during a cardiac cycle was compared in normal hearts and those with diastolic dysfunction. Mitral annular velocity (e') was found to decrease significantly (P < .0001) in subjects with abnormal transmitral filling patterns compared with normal subjects. The difference in e' among all the affected groups was not found to be significant (P = .68). The findings of this study suggest that patients with different patterns of transmitral diastolic filling show significant changes in LV vortex formation time despite the absence of significant differences in mitral annulus recoil during diastole.