Incidence of mitral valve prolapse in subjects with thoracic skeletal abnormalities--a prospective study.

The incidence of mitral valve prolapse (MVP) in 80 patients with various thoracic skeletal abnormalities (TSA) was examined prospectively using compete history and physical examination, chest x-rays, electrocardiography, phonocardiography, and echocardiography. There were 76 males and four females, ranging in age from 18 to 80 years. Thirty-four patients had narrow anteroposterior diameter of the chest (asthenic habitus) (Group 1), 13 had straight back (Group 2), and 33 had pectus excavatum (Group 3). Twenty-five of the 80 patients (31 per cent) had evidence of MVP, 22 by echocardiographic criteria and three by phonocardiographic criteria. The incidence of MVP in this predominantly male population was substantially higher than that reported in the general adult population. Thoracic skeletal abnormality is an important nonauscultatory feature of mitral valve prolapse syndrome. The association between TSA and MVP may be a manifestation of a single connective tissue defect during embryonic development of the bony thoracic cage and the atrioventricular valves. All patients with TSA, even when asymptomatic, should be screened for MVP by noninvasive investigations. The recognition of MVP in patients with TSA may be of potential value in prevention of life-threatening endocarditis and cardiac arrhythmia.