Cardiomegaly (sometimes megacardia or megalocardia) is a medical condition in which the heart is enlarged. As such, it is more commonly referred to simply as "having an enlarged heart". It is usually the result of underlying conditions that make the heart work harder, such as obesity, heart valve disease, high blood pressure (hypertension), and coronary artery disease. Cardiomyopathy is also associated with cardiomegaly.Cardiomegaly can be serious depending on what part of the heart is enlarged, and can result in congestive heart failure. Recent studies suggest that cardiomegaly is associated with a higher risk of sudden cardiac death.Cardiomegaly may improve over time, but many people with an enlarged heart (dilated cardiomyopathy) need lifelong treatment with medication. Having an immediate family member who has or had cardiomegaly may indicate that a person is more susceptible to getting this condition. Signs and symptoms
For many people, cardiomegaly is asymptomatic. For others, if the enlarged heart begins to affect the bodys ability to pump blood effectively, then symptoms associated with congestive heart failure may arise, including:
Heart palpitations – the irregular beating of the heart, usually associated with a valve issue inside the heart. Severe shortness of breath (especially when physically active) – irregularly unable to catch ones breath. Chest pain
Coughing, when lying down
Fatigue
Swelling in legs
Increased abdominal girth
Weight gain
Edema – swelling
FaintingThere is not much variation in these symptoms because they are mostly specific to the chest area. However, some are more common than others depending on each patient.
Mucolipidosis type IV (ML IV, ganglioside sialidase deficiency, or ML4) is an autosomal recessive lysosomal storage disorder. Individuals with the disorder have many symptoms including delayed psychomotor development and various ocular aberrations. The disorder is caused by mutations in the MCOLN1 gene, which encodes a non-selective cation channel, mucolipin1. These mutations disrupt cellular functions and lead to a neurodevelopmental disorder through an unknown mechanism. Researchers dispute the physiological role of the protein product and which ion it transports. Signs and symptoms
Most patients with ML IV show psychomotor retardation (i.e., delayed development of movement and coordination), corneal opacity, retinal degeneration and other ophthalmological abnormalities. Other symptoms include agenesis of the corpus callosum, iron deficiency resulting from an absence of acid secretion in the stomach, achlorhydria. Achlorhydria in these patients results in an increase in blood gastrin levels. These symptoms typically manifest early in life (within the first year). After disease onset there occurs a period of stability, typically lasting two to three decades during which very little disease progression occurs. Pathophysiology
Mucolipin1 is thought to be localized in endosomes. An important property of mucolipin1 is that decreasing pH (acidification) results in deactivation of the protein, likely through an assembly defect. There are at least 29 known mutations in MCOLN1, located throughout the gene. Many of the known mutations result in no expression of mucolipin1. Milder mutations, such as ΔF408 and V446L, produce a dysfunctioning form of the cation channel.