Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased ventricular wall thickness or mass in the absence of loading conditions (hypertension, valve disease) sufficient to cause the observed abnormality.

Diffuse thickening of the ventricular endocardium and by associated myocardial dysfunction

An abrupt loss of heart function.

Increased size of the heart, clinically defined as an increased transverse diameter of the cardiac silhouette that is greater than or equal to 50% of the transverse diameter of the chest (increased cardiothoracic ratio) on a posterior-anterior projection of a chest radiograph or a computed tomography.

The presence of an abnormality of cardiac function that is responsible for the failure of the heart to pump blood at a rate that is commensurate with the needs of the tissues or a state in which abnormally elevated filling pressures are required for the heart to do so. Heart failure is frequently related to a defect in myocardial contraction.

An abnormality of the mitral valve characterized by insufficiency or incompetence of the mitral valve resulting in retrograde leaking of blood through the mitral valve upon ventricular contraction.

Failure of the tricuspid valve to close sufficiently upon contraction of the right ventricle, causing blood to regurgitate (flow backward) into the right atrium.

Increased time between the start of the Q wave and the end of the T wave as measured by the electrocardiogram (EKG).

In this case the right ventricle is more muscular than normal, causing a characteristic boot-shaped (coeur-en-sabot) appearance as seen on anterior- posterior chest x-rays. Right ventricular hypertrophy is commonly associated with any form of right ventricular outflow obstruction or pulmonary hypertension, which may in turn owe its origin to left-sided disease. The echocardiographic signs are thickening of the anterior right ventricular wall and the septum. Cavity size is usually normal, or slightly enlarged. In many cases there is associated volume overload present due to tricuspid regurgitation, in the absence of this, septal motion is normal.

Hypertrophic cardiomyopathy with an symmetrical and concentric pattern of hypertrophy.

The dividing wall between left and right sides of the heart, thickens and bulges into the left ventricle.

Abnormal function of the left ventricule during left ventricular relaxation and filling.

An increase in size of the ventricular system of the brain.

Pterygia are 'winglike' triangular membranes occurring in the neck, eyes, knees, elbows, ankles or digits.

Hydrops fetalis is a descriptive term for generalized edema of the fetus, with fluid accumulation in extravascular components and body cavities. It is not a diagnosis in itself, but a symptom and end-stage result of a wide variety of disorders. In the case of immune hydrops fetalis, a frequent cause is maternofetal incompatibility as in that related to a number of genetic anemias and metabolic disorders expressed in the fetus; in other instances, it remains idiopathic and likely multifactorial (summary by Bellini et al., 2009). Nonimmune hydrops fetalis accounts for 76 to 87% of all described cases of hydrops fetalis (Bellini et al., 2009). Genetic Heterogeneity of Hydrops Fetalis In southeast Asia, alpha-thalassemia (604131) is the most common cause of hydrops fetalis, accounting for 60 to 90% of cases. Almost all of these cases result from homozygous deletion of the HBA1 (141800) and HBA2 (141850) genes. A few cases have been reported that had 1 apparently normal alpha-globin gene, termed the hemoglobin H (613978) hydrops fetalis syndrome (summary by Chui and Waye, 1998). Other genetic disorders predisposing to NIHF include other congenital anemias, such as erythropoietic porphyria (e.g., 606938.0013), and many metabolic disorders, such as one form of Gaucher disease (e.g., 606463.0009), infantile sialic acid storage disease (269920), mucopolysaccharidosis type VII (253220), glycogen storage disease IV (232500), congenital disorder of glycosylation type Ia (212065), and disorders of lymphatic malformation (see, e.g., LMPHM1, 153100).

An increase in cell size, enhanced protein synthesis, and heightened organization of the sarcomere within cardiac myocytes.