Valvular disease is a condition in which the valves of the heart do not function properly due to damage or a defect in one, two or all four heart valves, which are the tricuspid, pulmonary, mitral, and aortic. The former two are situated on the right side, while the latter ones are on the left side of heart. Normally functioning valves ensure that blood flows with proper force in the proper direction at the proper time. In valvular heart disease, the valves become too narrow and hardened to open fully, or are unable to close completely. When the valve is too narrow, the valvular disease is called valve stenosis (mitral stenosis, aortic stenosis, tricuspid stenosis, and pulmonary valve stenosis). When the a heart valve does not close tightly, then it is a valve insufficiency (or regurgitation).
When a valve has become too narrow, or stenotic, blood is forced to back up in the adjacent heart chamber, while an incompetent valve allows blood to leak back into the chamber it was pumped from. To compensate for poor pumping action, the heart muscle enlarges and thickens, thereby losing elasticity and efficiency. In addition, in some cases, blood pooling in the chambers of the heart has a greater tendency to clot, increasing the risk of stroke or pulmonary embolism. Valvular disease may be congenital (inborn) or acquired (due to another cause later in life). Treatment may be with medication but often (depending on the severity) involves valve repair or replacement (insertion of an artificial heart valve).
Heart Valvular Disease Video (Jonathan Zaroff, MD, Director Coronary Care Unit, UCSF, Medical Center)