Relationship between segmental abnormalities and global left ventricular function in coronary artery disease:...

A theoretical model of the heart, which suggests a direct relationship between segmental abnormalities of left ventricular (LV) wall motion (WM) and LV ejection fraction (EF), was tested using two-dimensional echocardiography (2DE) and multiple-gated equilibrium blood pool scintigraphy (MGES) in a population of 25 coronary artery disease patients. MGES was used to determine EF, and 2DE was used to develop a method of analysis of LV segmental WM abnormalities. Two orthogonal apical 2DE views were analyzed. The length of the end-diastolic segments in which normal contraction occurred during systole were measured in each view, summed and divided by the sum of the end-diastolic silhouette lengths. The fraction thus created was multiplied by 100 and defined as the percentage of normally contracting myocardium (%NCM). %NCM correlated well with EF determined by MGES (r = 0.94). Determination of %NCM was highly reproducible for the same observer (r = 0.98), as well as for two observers (r = 0.98), and the standard error of estimate was low in both cases (4%). These findings, in addition to confirming the theoretical model, provide a new technique to assess LV segmental WM abnormalities by 2DE.