RELATIONSHIP BETWEEN MITRAL ANNULAR PLANE SYSTOLICEXCURSION AND LEFT VENTRICULAR EJECTION FRACTION BYMODIFIED SIMPSON’S METHOD USING POINT OF CARE CARDIACULTRASOUND: 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, leading to the advent of a number of different methods of assessment. The standard accepted method for this is modified Simpson’s method. This entails measurements of end-diastolic volume (EDV) and end-systolic volume (ESV) in two views from the area of left ventricle, giving the left ventricular ejection fraction (left ventricular ejection fraction). However, this takes time and may not be feasible in emergent conditions. 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. The average of septal and lateral movement of the mitral valve may correlate directly with myocardial contractility. Measurement of MAPSE offers certain advantages as compared to the modified Simpson’s method. MAPSE is technically easier to obtain when compared to modified Simpson’s method and can even be attempted with good accuracy by an untrained hand. It can be assessed even in patients with poor cardiac window as it does not rely on obtaining very specific sonographic images and is hence also quicker to assess. MAPSE therefore could prove to be a reliable substitute and it could offer a choice to the clinician between the two methods for left ventricular ejection fraction assessment, which is especially advantageous in emergent conditions and patients with poor cardiac window. A clinician will have the choice to measure only the MAPSE and still be able to predict to a certain degree of accuracy the left ventricular ejection fraction of a patient.

Currently, there are very few studies on the relationship between MAPSE and ejection fraction obtained by modified Simpson’s method. Either the equation has been calculated retrospectively or in specific patient populations. There is no universal equation available to calculate left ventricular ejection fraction from MAPSE. This study is therefore being designed to find the relationship between MAPSE with left ventricular ejection fraction measured by modified Simpson’s method and to derive and validate a generalized equation for the same.