cardiovascular disorders
Hypertrophic Cardiomyopathy
Key Points
Hypertrophic cardiomyopathy is usually due to one of numerous genetic mutations that cause various types of ventricular hypertrophy that restrict filling (ie, cause diastolic dysfunction) and sometimes obstruct LV outflow. Coronary blood flow may be impaired even in the absence of coronary artery atherosclerosis because capillary density is inadequate and the intramyocardial coronary arteries are narrowed by intimal and medial hyperplasia and hypertrophy. At a young age, patients may have chest pain, dyspnea, palpitations, syncope, and sometimes sudden death, typically triggered by exertion. Echocardiography is done, but, if available, MRI best shows the abnormal myocardium. Use beta-blockers and/or rate-limiting calcium channel blockers (usuallyverapamil) to decrease myocardial contractility and slow the heart rate and thus prolong diastolic filling and decrease outflow obstruction. Considermavacamtento decrease left ventricular outflow tract gradient, improve exercise capacity, and reduce symptoms. Avoid nitrates and other medications that decrease preload (eg, diuretics, angiotensin-converting enzyme inhibitors,angiotensin IIreceptor blockers) because these decrease left ventricular size and worsen left ventricular function. Place an implantable cardioverter-defibrillator for patients with syncope or sudden cardiac arrest. Do surgical myectomy oralcoholseptal ablation in patients with symptoms despite medical therapy. 