広仲 英治¹, 小島 昌治², 本郷 実², 深谷 幸雄³, 田中 正雄², 石井 恵子¹, 関口 守衛²

Eiji HlRONAKA¹, Shoji KOJIMA², Minoru HONGO², Yukio FUKAYA³, Masao TANAKA², Keiko ISHII¹, Morie SEKIGUCHI²

¹信州大学附属病院中央検査部, ²信州大学附属病院第1内科, ³信州大学附属病院第2外科

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

キーワード : Aortic valve prolapse, Chronic aortic regurgitation, Myxomatous degeneration

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.