Pathophysiology of hypertrophic cardiomyopathy determines its medical treatment

Physicians treating hypertrophic cardiomyopathy (HCM) are faced with unique management challenges. Appreciating overall good prog- nosis in unselected patients forms the basis for medical treatment. Treatment is tailored by the presence or absence of outflow tract gra- dient and individual symptoms. In all patients, formal stratification for sudden death risk is necessary, with consideration of defibrillator implantation in patients deemed to be at high risk. In patients with no or only mild symptoms the approach of watchful waiting is often app- ropriate. For symptomatic patients with non-obstructed disease medical treatment with calcium channel blockers and beta-blockers is ai- med to improve heart failure symptoms, and ischemia. Verapamil is the most often used, with likely benefit of relieving ischemia. Obstruc- tion, most commonly due to systolic anterior motion of the mitral valve (SAM) and mitral-septal contact, occurs in ≥50% of all HCM pati- ents, worsens symptoms and increases mortality. Successful medical treatment of obstruction with negative inotropes slows accelerati- on of left ventricular ejection with delay in SAM, ultimately yielding a lower pressure gradient. β-blockers are the first line treatment in obstructive HCM predominantly by mitigating provocable gradients. The magnitude of symptom relief with verapamil is similar to the effect of β-blockade. Disopyramide combined with β-blockade is thought by some to be the most effective medical treatment of obstruction, and has been shown to be safe and not pro-arrhythmic. Most symptomatic HCM patients with significant obstruction at rest or provocation can be successfully managed with long-term medication alone.