<unk> , or<unk> M, is a disease of the myocardium in which a portion of the myocardium is<unk> d without any alternate known cause such as hypertension, amyloid or aortic stenosis. Although<unk> M has gained notoriety as a leading cause of sudden cardiac death in young athletes, it should be noted that<unk> M is a cause of sudden cardiac death in any age group and may be associated with cardiac morbidity and disabling cardiac symptoms as well. There are two variants of<unk> : an obstructive variant, and a non-obstructive variant. A non-obstructive variant of<unk> M is known as apical<unk>  ,which is also known as nonobstructive<unk>  and Japanese variant<unk>  or the Yamaguchi variant (since the first cases described were all in individuals of Japanese descent). In<unk>  <unk> M), the sarcomeres in the heart replicate causing heart muscle cells to increase in size, which results in the thickening of the heart muscle. In addition, the normal alignment of muscle cells is disrupted, a phenomenon known as myocardial disarray. Myosin heavy chain mutations are associated with the development of familial<unk> .<unk> M also causes disruptions of the electrical functions of the heart.<unk>  is most commonly due to a mutation in one of 14 sarcomeric genes that results in a mutated protein in the sarcomere, the primary component of the myocyte. While most literature so far focuses on European, American, and Japanese populations,<unk> M appears in all racial groups. The prevalence of<unk> M is about 0.2% to 0.5% of the general population.<unk> M is frequently asymptomatic until sudden cardiac death, and that is why some experts suggest routinely screening certain populations for this disease. Echocardiographuc surveys in general population showed<unk> M in approximately 1 in every 500 people (0.2% of the general population). Only 15% of<unk> M patients have been diagnosed, which means the majority of patients with<unk> M are undiagnosed. The symptoms associated with<unk>  are quite variable and range from no symptoms,  to the development of heart failure, or sudden cardiac death. The symptoms may vary tremendously from individual even within a family (different penetrance). The timing of symptom onset is quite variable as well and may range from infancy to adulthood. Symptoms may include chest pain, dizziness, fainting, especially during exercise, heart failure (in some patients), hypertension, dizziness during activity or when standing up suddenly, sensation of feeling the heart beat (palpitations), shortness of breath, fatigue, reduced activity tolerance, and shortness of breath when lying down (orthopnea). The medical management of the patient with<unk>  involves minimizing diastolic dysfunction, reducing left ventricular outflow tract obstruction, optimizing heart failure management, maintaining normal sinus rhythm, rate control and anticoagulation in the presence of atrial fibrillation, and implantation of an automatic implantable cardiac defibrillator in selected patients such as those who survive sudden cardiac death.
Hypertrophic cardiomyopathy
Noncompaction cardiomyopathy
Restrictive cardiomyopathy
Dilated cardiomyopathy
Eosinophilic cardiomyopathy
Alcoholic cardiomyopathy
Aicardi syndrome
Stress cardiomyopathy