Relationship Of Tissue Doppler Imaging Systolic Velocity With Mitral Annular Plane Systolic Excursion And Left Ventricular Ejection Fraction By Modified Simpsons Method Using Cardiac Ultrasound An Observational Analytical Study

Point of care cardiac ultrasound is universally accepted as one of the most important tools for the assessment of the cardiac function of a patient. The ejection fraction is often taken as an indicator for left ventricular function and is a cornerstone for deciding management and interventions. However, there are various methods to assess Left ventricular ejection fraction (LVEF). The standard accepted method is the modified Simpson’s method. This entails calculation of end-diastolic volume (EDV) and end-systolic volume (ESV) from the area of left ventricle using two views, thereby calculating LVEF.  This measurement may not be accurate if the entire left ventricle is not visible, or the window is poor. It may take time to acquire the desired view, and as measurements are made in two views, precious time may be wasted, especially for an urgent assessment

Ventricular systole is a result of the contraction of longitudinal and circumferential fibers of the heart. The mitral annulus plane systolic excursion occurs as a result of the contraction of longitudinal fibers. It is hence a representative of the myocardial contractility and the ejection fraction. This displacement can be easily measured on M-mode of a cardiac ultrasound and is known as mitral annular plane systolic excursion or MAPSE.2 The average of septal and lateral movement of the mitral valve may correlate directly with myocardial contractility. It is technically easier to obtain and can even be attempted with good accuracy by an untrained hand. But it requires the lateral mitral annulus to move in the same plane of M-Mode cursor, which may be difficult to achieve under suboptimal conditions

Tissue Doppler Imaging (TDI) uses the principle of pulse wave doppler. High velocity low amplitude signals from RBCs are eliminated to display only the low velocity high amplitude signals for the myocardium. The two initial positive velocities correspond to LV isovolumic contraction velocity and peak systolic contraction velocity (s’) respectively

Peak systolic velocity is a sensitive marker of calculating Left Ventricle systolic function. TDI is technically much easier and has the lowest intra & inter observer variability. TDI s’ therefore could prove to be a reliable substitute and it could offer a choice to the clinician between the three methods for left ventricular ejection fraction assessment, which is especially advantageous in emergent conditions

LACUNAE IN EXISTING LITERATURE

There are only a few reported studies establishing a relationship of TDIs’ with MAPSE and LVEF, mainly in the western population with moderate success. There is no universal equation available to calculate left ventricular ejection fraction from TDI s’. This study is therefore being designed to find the relationship of TDI s’ with MAPSE and left ventricular ejection fraction measured by modified Simpson’s method and to derive and validate a generalized equation for the same.