Eccentric mitral regurgitation jets among patients having sustained inferior wall myocardial infarction

A strong association has been recognized between partial or complete mitral leaflet flail and highly eccentric mitral regurgitation jets. In light of anecdotal observation of eccentric mitral regurgitation apparently due to g eometric and functional changes accompanying inferior wall myocardial infar ction, the present study was performed to systematically study the eccentri city of mitral regurgitation jets complicating nonacute inferior wall myoca rdial infarction. Forty-eight consecutive patients with evidence of prior i solated inferior wall myocardial infarction and at least moderate mitral re gurgitation but without other valvular, annular, chordal, or ventricular pa thology potentially contributory to mitral regurgitation were studied. Mitr al regurgitation jets were characterized with respect to eccentricity and a nterior versus posterior direction. Regurgitantjet and mitral leaflet posit ion were quantified relative to the mitral annulus. Five of 48 patients (10 .4%) had eccentric jets, of which four were directed posterior and one ante rior. Although not reaching statistical significance, patients with eccentr ic jets tended to have somewhat smaller left atrial size (41.2 +/- 7.8 vs 4 7.2 +/- 9.3 mm, P = 0.17) and left ventricular size (51.5 +/- 3.4 vs 55.1 /- 7.8 mm, P = 0.13), and higher left ventricular ejection fraction (0.52 /- 0.11 vs 0.46 +/- 0.09, P = 0.25) compared with,patients with noneccentri c jets. Leaflet position. relative to the mitral annulus was significantly different among patients with eccentric compared with noneccentric posterio r Jets (54 +/- 10 degrees vs 33 +/- 11 degrees, P = 0.02), implying greater leaflet restriction, toward the left ventricular apex. In conclusion, appr oximately one in 10 patients with isolated inferior wall myocardial infarct ion and at Least moderate mitral regurgitation, was found to have marked ec centricity of the regurgitant jet. Leaflet position was more apically displ aced among patients with eccentric jets, suggesting greater leaflet restric tion in systole. The finding of a highly eccentric posterior mitral regurgi tation jet can be due to inferior wall myocardial infarction with posterior leaflet restriction, as well as partial or complete anterior mitral leafle t flail.