Novel insights into the clinical manifestations and treatment of hypertrophic cardiomyopathy.

Knowledge of the pathophysiology, clinical manifestations, and treatment of hypertrophic cardiomyopathy continues to evolve. In subaortic obstructive hypertrophic cardiomyopathy, the importance of elongated mitral leaflets in causing the outflow obstruction and concomitant mitral regurgitation has been further elucidated, and marked worsening of the obstruction during upright exercise has been clearly demonstrated. Treatment options now include dual chamber pacing as well as medical and surgical therapy. The syndrome of midventricular obstruction with apical infarction and aneurysm formation most commonly results from apical infarction in the presence of extensive apical hypertrophy, with the noninfarcted midventricular hypertrophic tissue responsible for the midventricular obstruction. Attention is drawn to the variable pathophysiology and frequency of subaortic obstruction in hypertrophic cardiomyopathy in the elderly, the etiology of which is probably multifactorial. Finally, the interrelationship of impaired ventricular relaxation, coronary flow dynamics, and myocardial ischemia is discussed.