Hypertrophic Cardiomyopathy: Getting To The Thick Of It

B. Davis Campbell, MSN, CRNP

1. Definition: HCM is hypertrophy of the myocardium more than 1.5cm without an identifiable cause.

2. Prevalence: HCM occurs in 0.2% to 0.5% of general population or 600,000 people in the USA. Occurs in all racial groups, affects men and women equally.

3. HCM can be obstructive or non-obstructive, depending on the presence of a left ventricular outflow tract gradient, either at rest or with provocative maneuvers.

4. Characteristics of obstructive HCM include asymmetric left ventricular hypertrophy involving the interventricular septum and left ventricular outlet tract obstruction due to systolic anterior motion of the anterior leaflet of the mitral valve.

5. Genetically, HCM is caused by increase in the sarcomeres and myocytes in the heart muscle, leading to myocardial disarray.

6. of obstructive HCM vary. However patients may have dyspnea, , lightheadedness, fatigue or syncope. Complications include atrial fibrillation, ventricular arrhythmias, or congestive heart failure with sudden death.

7. On physical exam, patients may have a systolic which may increase or decrease based on specific maneuvers.

8. Medical treatment for obstructive cardiomyopathy includes beta blockers and negative isotropes. Surgical treatment includes alcohol septal ablation, myomectomy, and pacemaker (now obsolete). Patients may also need an internal cardio-defibrillator (ICD). If all else fails, may need cardiac transplant.

9. Treatment for non-obstructive cardiomyopathy includes beta blockers, calcium channel blockers, diuretics, cardiac transplant and ICD.

10. All athletes should have a physical exam before competing. All athletes with a systolic murmur should have an echocardiogram or further testing. First degree relatives of a patient with HCM should be tested.

Contact info: B. Davis Campbell [email protected]