SUMMARY Clinical acceptance of an association between papillary muscle dysfunction and mitral regurgitation is widespread, despite the lack of objective support. To evaluate a possible association, we performed echocardiographic examinations on 22 patients with prior myocardial infarction and clinical evidence of papillary muscle dysfunction, 40 patients with prior myocardial infarction and no clinical evidence of papillary muscle dysfunction, and 20 normal subjects. There was a unique pattern of incomplete mitral leaflet closure ina high percentage (91%) of infarct patients with mitral regurgitation. In these patients, one or both leaflets we3e effectively arrested within the cavity of the left ventricle during ventricular systole. Dyskinetic wall motion in the region immediately surrounding one of the papillary muscles was present in 23 of 24 patients (96%) with demonstrated incomplete closure. This study provides the first objective evidence that de novo mitral regurgitation in patients with prior myocardial infarction is due to dyskinesis involving the left ventricular myocardium beneath one of the papillary muscles, producing increased tension on the mitral leaflets and preventing normal closure.MITRAL INSUFFICIENCY has been recognized for many years to result from disorders of the mitral leaflets, chordae tendineae, annulus and related structures.'-' In 1963, Burch and colleagues directed attention to the possible etiologic role of papillary muscle dysfunction in producing mitral valve incompetence.4" They suggested two mechanisms by which this might occur. First, ischemia or fibrosis of a papillary muscle might prevent normal contraction. This would weaken systolic support for the valve leaflets and result in leaflet eversion or prolapse into the left atrium. Alternatively, ischemia or infarction of the left ventricular myocardium at the base of a papillary muscle might produce dyskinesis in this region. This would pull the papillary muscle away from the valve orifice, increasing tension on the leaflets and preventing complete closure.Angiographic studies have shown the occurrence of mitral valve prolapse in association with ischemic disease involving a papillary muscle, supporting the occurrence of the first of these two phenomena.6 7 Angiography is poorly suited to demonstrate displacement of a leaflet downward into the cavity of the ventricle. As a result, the alternative mechanism, leaflet arrest with resultant malapposition and valvular incompetence, has not been shown to occur.Cross-sectional echocardiography is a noninvasive method of assessing mitral leaflet motion through the cardiac cycle in multiple tomographic planes. As motion in patients with clinical papillary muscle dysfunction. The purposes of this study were (1) to determine whether abnormal leaflet motion or closure patterns could be observed by the cross-sectional echocardiogram in patients with clinical evidence of papillary muscle dysfunction, and (2) if abnormal motion did occur, how it related to the mechanisms proposed for leafl...

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SUMMARY Advances in two-dimensional echocardiography have improved the prospects of using this technique to detect left main coronary artery (LMCA) obstruction. Using an echocardiograph that had digital gray scale, a 3-MHz transducer and strobe freeze-frame capability and reviewing recordings on an off-line videotape-videodisc analyzer, we retrospectively examined the LMCA in 72 patients who underwent coronary cineangiography. Angiography showed 50% or greater LMCA obstruction in seven patients. All seven had high-intensity echoes in the walls of the LMCA. The high-intensity echoes were irregularly located in the artery and partially occluded it. The LMCA could frequently be recorded proximal and distal to the obstruction. A blinded observer reviewed 28 randomly selected patients from this group and correctly identified the four patients with LMCA obstruction. There was one true and two questionable false-positive diagnoses. In a prospective study of 31 patients, two independent observers correctly identified the three patients with LMCA obstruction. There were no false negatives, and one observer had one false positive. All of the false positives were in patients with proximal left anterior descending coronary artery obstructions. Echocardiography may be a practical means of identifying patients with the LMCA obstruction.ALTHOUGH the effect of coronary bypass surgery on the natural history of coronary artery disease is controversial, there is a consensus that surgery improves life expectancy in patients with left main coronary artery (LMCA) obstruction.'-" This observation and the usually ominous prognosis for patients with LMCA obstruction" have made the detection of this form of coronary artery disease extremely important. Selective coronary cineangiography provides the only reliable diagnosis of LMCA obstruction despite the