INCIDENCE AND RISK-FACTORS FOR MITRAL-VALVE PROLAPSE IN SEVERE ADOLESCENT IDIOPATHIC SCOLIOSIS

Mitral valve prolapse (MVP) is known to be associated with thoracic sk eletal anomalies. To determine the incidence and risk factors for mitr al valve prolapse in the adolescent population with severe idiopathic scoliosis (IS), a prospective follow-up study on 139 adolescent patien ts with IS from the Pediatric Orthopedic Service was undertaken. Data collected included age, sex, medical and family history, physical exam , electrocardiogram and echocardiogram, spinal x-rays, and pulmonary f unction tests, MVP was detected by echocardiogram in 13.6% (19/139) of patients with IS as compared with 3.2% in 154 age-and weight-matched controls (p < 0.006), All patients with MVP were asymptomatic and a sy stolic click or murmur was detected on the single preoperative exam on ly in 37% (7/19) of them. Patients with MVP and IS weighed less (45.1 +/- 2.0 vs 51.8 +/- 0.1 kg, p < 0.002) as compared with those IS patie nts without MVP. The electrocardiogram was abnormal in 21% (4/19) of p atients with MVP as compared with only 1.6% (2/120) of patients with I S but no MVP. The two groups did not differ with respect to age at dia gnosis, severity of scoliosis, positive family history of scoliosis, o r the presence of restrictive lung disease. Though IS was more prevale nt in females (79%), the presence of MVP was not related to gender, MV P was persistent in 10 of the 19 patients reevaluated by echocardiogra m 2-4 years after spinal surgery. We conclude that MVP is four times m ore common in patients with severe IS than in the normal adolescent po pulation, and is associated with a lower body weight in IS patients wi th MVP than in IS patients without MVP, The persistent nature of MVP, even after corrective spinal surgery, may be related to factors other than geometric changes of the heart caused by abnormal thoracic curvat ure.