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General Reference ⬇

Nejm 1989;320:1234; Ann IM 1989;111:305

Pathophys and Cause ⬆ ⬇

Cause:Genetic, autosomal dominant; decreased penetrance in males; less frequent over age 50 yr

Pathophys:Abnormal cordae and valve, not papillary muscle. Atrial muscle in valve may also produce electrical atrial and ventricular bypass tracts and reentrant arrhythmias (Nejm 1982;307:369)

Epidemiology ⬆ ⬇

Associated with various inherited connective tissue diseases including Ehler-Danlos syndrome, Marfan's, osteogenesis imperfecta, pseudoxanthoma elasticum (Nejm 1982;307:369), and von Willebrand's disease (Nejm 1981;305:131). Prevalence <2.5% in adults ([Framingham] Nejm 1999;341:1,8)

Signs and Symptoms ⬆ ⬇

Sx:Palpitations (premature junctional beats, PACs, PVCs), anxiety often leads to discovery although no more prevalent in anxious pts than in normals

Si:Midsystolic click (92%), late systolic murmur (85%), which moves toward S1 with standing or other decrease in venous return. Tricuspid prolapse may occur too (6/13—Nejm 1972;287:1218)

Course ⬆ ⬇

Same as matched controls at Mayo (Nejm 1985;313:1305); 90% 10-yr survival, <10% get major cmplc listed below

Complications ⬆ ⬇

Sudden death rarely (2.5% at Mayo?—Nejm 1985;313:1305); PVCs associated with sx, present in 16% of children with Barlow's on ETT (J Peds 1984;105:885); endocarditis (1% at Mayo—Nejm 1985;313:1305; 3%—Nejm 1989;320:1031); CVA/TIAs (Nejm 1980;302:139) vs no incr rates (Nejm 1999;341:8); Graves' disease (Nejm 1981;305:497); valvular insufficiency requiring surgery in 6% (Nejm 1989;320:1031)

r/o benign MVP w insignificant mitral regurgitation = 2/3 of all w MVP (Nejm 1989;320:1031)

Lab and Xray ⬆ ⬇

Lab:

Noninv:EKG normal in 76%; may show "inferior ischemia" or PVCs

Echocardiogram

Treatment ⬆

Rx:

SBE prophylaxis no longer recommended (2007 AHA guidelines)

Propranolol or other beta.gif-blocker rarely needed

Surgical valve replacement occasionally (<5%) necessary if severe mitral regurgitation, esp in men >60 yr old