Electrocardiographic Abnormalities and Coronary Arteriograms in the Mitral Click-Murmur Syndrome

Abstract
"Ischemic" electrocardiographic changes are frequently associated with a mid-systolic click and late systolic murmur. Neither the cause of these electrocardiographic changes nor the natural history of patients with this syndrome has been determined. Five patients with the auscultatory findings of the "mitral click syndrome," as well as "ischemic" electrocardiographic changes, were studied because coronary-artery anomalies or disease was suspected. Phonocardiograms were obtained with patient supine and upright, and during amyl nitrite inhalation, Valsalva maneuver and phasic respiration. Four of five graded bicycle exercise tests were normal, and there were no arrhythmias. At catheterization, prolapsed posterior-mitral-valve leaflets and normal coronary arteriograms were found in all five patients. Repeat catheterizations in two patients spanning five and eight years revealed mild progression in severity of the mitral-valve prolapse. In patients with mitral-valve prolapse the associated "ischemic" electrocardiographic abnormalities are apparently not due to large-vessel coronary-artery lesions. (N Engl J Med 289:127–131, 1973)