Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is the thickening of the muscles that make up the heart. The thickening may interfere with the normal functioning of the heart by:

Narrowing the outflow of the ventricleReducing the ability of the heart to relax and fill with blood during the relaxation phaseReducing the ability of the valves of the heart to function properly

Any situation that increases the contraction or rate of contraction of the heart muscle can worsen these symptoms.