Mitral regurgitation (MR), also known as mitral insufficiency or mitral incompetence, is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood. It is the abnormal leaking of blood backwards – regurgitation from the left ventricle, through the mitral valve, into the left atrium, when the left ventricle contracts. Mitral regurgitation is the most common form of valvular heart disease. Definition
Mitral regurgitation, also known as mitral insufficiency or mitral incompetence, is the backward flow of blood from the left ventricle, through the mitral valve, and into the left atrium, when the left ventricle contracts, resulting in a systolic murmur radiating to the left armpit. Signs and symptoms
Mitral regurgitation may be present for many years before any symptoms appear. The symptoms associated with MR are dependent on which phase of the disease process the individual is in. Individuals with acute MR are typically severely symptomatic and will have the signs and symptoms of acute decompensated congestive heart failure (i.e. shortness of breath, pulmonary edema, orthopnea, and paroxysmal nocturnal dyspnea). In acute cases, a murmur and tachycardia may be the only distinctive signs.Individuals with chronic compensated MR may be asymptomatic for long periods of time, with a normal exercise tolerance and no evidence of heart failure. Over time, however, there may be decompensation and patients can develop volume overload (congestive heart failure). Symptoms of entry into a decompensated phase may include fatigue, shortness of breath particularly on exertion, and leg swelling.
Pallister–Hall syndrome (abbreviated PHS) is a disorder that affects the development of many parts of the body. It is named for Judith Hall and Philip Pallister. Presentation
Most people with this condition have extra fingers and/or toes (polydactyly), and the skin between some fingers or toes may be fused  (cutaneous syndactyly). An abnormal growth in the brain called a hypothalamic hamartoma is characteristic of this disorder. In many cases, these growths do not cause any medical problems; however, some hypothalamic hamartomas lead to seizures or hormone abnormalities that can be life-threatening in infancy. Other features of Pallister–Hall syndrome include a malformation of the airway called a bifid epiglottis, laryngeal cleft, an obstruction of the anal opening (imperforate anus), and kidney abnormalities. Although the signs and symptoms of this disorder vary from mild to severe, only a small percentage of affected people have serious complications. Seizures
As noted above, the hypothalamic hamartoma can cause seizures. The most common types of seizures that occur are known as gelastic epilepsy. The term gelastic originates from the Greek word "gelos which means "laughter". Seizures may begin at any age but usually before three or four years of age. The seizures usually start with laughter and the laughter is often described as being "hollow" or "empty" and not very pleasant. The laughter occurs suddenly, comes on for no obvious reason and is usually completely out of place.