1Central Clinical Laboratories Shinshu University Hospital, 2First Department of Internal Medicine Shinshu University School of Medicine, 3Second Department of Surgery Shinshu University School of Medicine
We studied the echocardiographic characteristics of the aortic valves of 17 patients who had severe chronic aortic regurgitation of unknown etiology and had aortic valve replacement surgery. The study population comprised 14 men and 3 women aged 53 to 73 years (mean, 64 years). Fifteen (88%) of the 17 patients had aortic valve prolapse, which most frequently involved in the right coronary cusp (RCC) (n=13). Severity of prolapse was also higher in the RCC than in the left coronary cusp (LCC) or the noncoronary cusp (NCC). Diastolic fluttering of the prolapsed RCC was evident in 3 patients who exhibited musical diastolic murmur. Increased echo intensity of the aortic valve, especially at the tip of the cusps, observed in 9 patients, corresponded to the focal thickening of the free edges of the cusps, which was identified during surgery. Preoperative echocardiographic examination failed to correctly diagnose the aortic valve characteristics confirmed on surgery, however. These included diffuse mild thickening, thinning, retraction, perforation, and tearing. Histopathologic examination of the excised valves showed myxomatous degeneration in all but one, despite the echocardiographic and surgical findings. We conclude that severe chronic aortic regurgitation without a specific etiology is caused mainly by myxomatous degeneration that results in aortic valve prolapse in elderly patients. Echocardiographic findings, such as prolapse, increased echo intensity of the cuspal tip, and diastolic fluttering of the aortic valve, suggest myxomatous changes in the valve.