Background-.Echocardiography has evolved as a well-established part of the evaluation of global myocardial function. Tissue Doppler echocardiography is a novel technique with wide applications, including estimation of myocardial systolic function. We hypothesized that velocity time integral (VTI) of systolic mitral annular velocity had a better correlation with systolic function in comparison to peak velocity. Consequently, for the first part of our investigation, we selected a population with near normal systolic function to show initially the linear correlation and secondly to obtain the normal values.
Methods- We conducted a cross-sectional study at the echo lab with prospective simple nonrandom data collection on 50 consecutive patients (26 % normal, 38% CAD, 20% HTN, 10% MVP and 6% miscellaneous), mean age 45.6 yrs. (range: 18-80 yrs.) and 42% female. The exclusion criteria were prosthetic valves, LV systolic dysfunction, and/or severe regional wall motion abnormality, significant regurgitation (MR and/or AR), severe mitral annular calcification (MAC), non-sinus rhythm, paradoxical septal motion and poor endocardial line definition. All underwent complete echocardiographic study including TDI; some of the indexes of PW-TDI, with special attention to the systolic velocity of mitral annulus (Sm), were correlated with three different methods of EF measurement.
Results- The mean ejection fraction and VTI of Sm were 61.68% and 1.6594, respectively. Of TDI indices, linear regression analysis showed that VTI of Sm had the strongest statistical correlation with EF measured by Simpson’s method (p=0.014, EF= 50.1 + 6.96 X VTI).
Conclusion- Despite some inevitable limitations, our preliminary data suggest that peak velocity and particularly VTI of Sm in PW-TDI can be considered as reliable, rapid and reproducible indicators of preserved LV systolic function. However, we are currently conducting another complementary study to compare PW-TDI of Sm in patients with LV systolic dysfunction with or without mitral regurgitation.