[Incomplete spontaneous rupture of the supravalvular aorta complicated by pericarditis and aortic insufficiency].

The natural history of an incomplete spontaneous rupture of the ascending aorta over a 4-year period is reported. The initial presentation was subacute pericarditis which regressed spontaneously. Aortic regurgitation developed on the 100th day of the disease and was perfectly well tolerated haemodynamically for 4 years. This favourable course was interrupted by type I aortic dissection. The post-mortem examination provided an explanation for the peculiar development and course of the aortic regurgitation: it was due not to the usual prolapse of the cups but to displacement of the left posterior commissure by the retractile fibrosis arising from the lower lip of the spontaneous rupture.