Exercise Intolerance in Non-obstructive Hypertrophic Cardiomyopathy

Inclusion Criteria:

1. Patients 18 to 80 years of age with diagnosis of hypertrophic cardiomyopathy1 defined by left ventricular hypertrophy with end-diastolic wall thickness 15 mm or greater on 2D echocardiography in the absence of other primary causes of left ventricular hypertrophy or wall thickness between 13 and 15 mm in the presence of other features suggestive of hypertrophic cardiomyopathy, such as systolic anterior motion of the mitral valve leaflets, family history of hypertrophic cardiomyopathy, or positive genetic test result.
2. Left ventricular outflow tract gradient \<30 mmHg at rest and with provocation.
3. Left ventricular ejection fraction ≥ 50% by biplane Simpson's method.
4. Access to exercise equipment at home or at a fitness center.
5. Ability to complete study related testing including online surveys and smart phone use
6. Ability to perform 24 weeks of exercise training

Exclusion Criteria:

1. History of exercise-induced syncope or ventricular arrhythmias
2. LVOT obstruction being evaluated for septal reduction therapy; less than 3 months after
3. History of septal reduction therapy - surgery or ablation
4. History of ICD placement in the previous 3 months
5. History of hypotensive response with exercise testing (\>20 mm Hg decrease of systolic blood pressure from baseline blood pressure or an initial increase in systolic blood pressure followed by a decrease of systolic blood pressure \>20 mm Hg)
6. Clinical decompensation in the previous 3 months, defined as New York Heart Association class IV congestive heart failure symptoms or Canadian Cardiovascular Society class IV angina symptoms
7. Left ventricular ejection fraction less than 50% by echocardiography
8. Life expectancy less than 12 months
9. Pregnant or planned pregnancy
10. Inability to exercise owing to any medical or other limitations
11. Unwillingness to refrain from competitive sports, burst activity, or heavy isometric exercise for the duration of the study, if assigned to the non-exercise group.