HCM causes the heart muscle wall to thicken and stiffen, making it harder for the heart to fill with blood. When HCM causes the heart muscle to get so thick that it blocks or reduces blood flow from the heart to the rest of the body, it’s called obstructive HCM. Obstructive HCM is also referred to as HOCM (short for hypertrophic obstructive cardiomyopathy), and you may have heard this term in discussions with your doctor.
Obstructive HCM makes it difficult for the heart muscle to relax, so the heart must work harder and use more energy. When you have symptoms with obstructive HCM, it’s called symptomatic obstructive HCM. These symptoms can increase with physical exertion and worsen over time.