Valvular heart disease (VHD) is a type of heart disease that involves the heart valves, which are one-way doors that direct the flow of blood. Degenerative valve disease is the most common form of VHD in the United States, while rheumatic heart disease accounts for the majority of valve pathology in developing countries. The heart has four valves: mitral and aortic (left side) and tricuspid and pulmonic (right side). Blood is pumped through the heart in one direction. A normal functioning valve opens to allow blood to flow through and closes to prevent backflow of blood. Diseases of the valve could be due to regurgitation or insufficiency (blood leaking back in the wrong direction) or stenosis (valve does not open enough blocking blood flow). Regurgitation occurs when the valves do not close properly, and blood flows backward instead of forward, making the heart work harder, which leads to enlargement and decreased pump function. Stenosis happens when the valves are thickened or fused, which also leads to more work for the heart. VHD may be present at birth or due to infections, heart damage or heart attack.
The presence of a heart murmur does not always indicate heart disease. It may be present in a person with a normal heart. Before the advent of antibiotics, rheumatic heart disease was the most common cause of VHD. Valve disease may be congenital, like an abnormal shaped aortic or narrowed mitral valve. Acquired diseases could be from weakening of the valves as in mitral valve prolapse (myxomatous degeneration), build up of calcium causing thickening of the valves (calcific degeneration), infection (rheumatic fever, infective endocarditis), heart attack or coronary artery disease, cardiomyopathy (weakness of heart muscle), radiation treatment, connective tissue disorders and use of anti-obesity drugs like Fen-phen, which have been removed from the market after being linked to VHD.
Symptoms depend on the type and severity of valve disease. Patients may remain asymptomatic until the valves deteriorate. Patients with diseased heart valves may present with symptoms of shortness of breath, fatigue, weakness, dizziness and loss of consciousness. Symptoms may be more pronounced with activities, although they could occur even at rest. Some patients complain of palpitations, chest pain, leg swelling and weight gain. Congestive heart failure, disease of the heart muscle, irregular rhythms and blood clots may develop.