- Etiology: (familial inheritance)
    - no anatomic stenosis
    - anterior leaf of MV moves against Hypertrophied septum, blocking outflow;

- Sequelae:
     - sudden death is common;
     - L.V.H.
     - mitral valve dysfunction.

- Physical Exam:
     - pulse collapses w/ onset of mid-systolic murmur; (murmur heard best at lower left sternal border)
     - ejection click is not present.
     - carotid pulse: brisk rise from initial fast ejection, rapid drop.

Sudden Death in Young Athletes.