Hypertrophic Cardiomyopathy (HCM) often affects individuals and families with variable levels of severity. HCM occurs when the heart muscle cells thicken which leads to thickening of the walls of the heart. Unlike the thickening of the heart that occurs with chronically elevated blood pressure, HCM is a condition that the patient (and often the patient’s family) is genetically predisposed to developing. HCM is rare (affecting 0.2% of the population) and is often undetectable early in life, when symptoms are absent. However, HCM can become manifest early in life and may present as one of the most common causes of sudden cardiac death in the young; and remains most common cause of sudden cardiac death in young athletes.
HCM is preprogrammed to occur in affected individuals and has been attributed to gene defects that cause uncontrolled thickening of heart muscle walls and is associated with cardiac arrhythmias that may prove lethal if left undetected.MediVisualsTM
Various types of HCM exist. Some forms show global thickening of the muscle primarily in the left (but also right) main pumping chamber of the heart, the left ventricle (LV), whereas other types show asymmetric thickening in portions of the LV. Patients older than 35 years of age usually present later in life with symptoms consisting of shortness of breath and/or chest pain.
Although several forms of HCM can cause shortness of breath in adults, the primary cause of fatigue and shortness of breath in adults is often from the "obstructive" form of HCM, hypertrophic obstructive cardiomyopathy (HOCM). HOCM produces a narrowing just below the heart valve in the left side of the heart which blocks or obstructs flow of blood out of the heart. HOCM can also lead to compromise of the other valve in the left side of the heart, the mitral valve. Patients with this form of HCM often suffer from exertional or exercise-related shortness of breath and may suffer from frequent fainting spells (syncope) while active.MediVisualsTM