The tricuspid valve, mitral valve, pulmonic valve and aortic valve comprise the four valves in the heart that control the flow of blood from the upper heart chambers to the lower heart chambers, as well as to the lungs and the body. Complications of valvular heart disease depend on which valve is involved and to what degree. Symptoms range from mild to severe.
Causes
Some valvular disorders result from congenital defects, while others occur from disease processes such as rheumatic fever, a systemic illness that occurs following a group A streptococci infection. Coronary artery disease causes decreased blood flow to heart tissue, which can damage heart valves. Infective endocarditis, a bacterial infection of the heart, damages the tricuspid and mitral valves. Other, less common, causes of heart valve disease include chest radiation, the connective tissue disorder called Marfan syndrome and trauma.
Effects
Tricuspid and mitral valve disorders can lead to increased pressure in the affected atria and heart muscle irritability. Arrhythmias, or irregular heart rhythms, commonly occur. Atrial fibrillation is the most prevalent arrhythmia that causes a rapid and irregular heart rate. This arrhythmia requires medical treatment to restore a normal heart rhythm in order to prevent low blood pressure, fatigue and stroke. Stroke is a risk because diseased heart valves cause blood clots to form. According to "Medical-Surgical Nursing--Critical Thinking for Collaborative Care," blood pools in the affected heart chamber, inducing clot formation. The clots that form in the heart can break loose and be pumped into the central circulation. Commonly, clots travel to the brain and cause a stroke.
Features
Incompetent heart valves do not control the flow of blood through the heart chambers. Blood backs up into places it should not be, such as the upper heart chambers and the lungs. If the diseased valve is left untreated, the potential exists for pulmonary congestion and heart failure to develop. The long-term prognosis for these conditions is poor, with a heart transplant being the ultimate treatment.
Treatment
Patients with severe valvular heart disease require surgical repair or replacement of the diseased heart valve. An article published in the May 2009 issue of the "American Nurse Today" emphasizes the preference to conduct surgical repair of a diseased valve, particularly the mitral valve, rather than replacement with a prosthetic valve. Although surgical repair is a more complicated procedure, the benefits to the patient outweigh the ease of replacing a heart valve. Patients who undergo surgical repair of a heart valve do not require life-long blood-thinning medication to prevent the formation of clots that occur with a prosthetic valve.
Expert Insight
The American Heart Association and the American College of Cardiologists created a task force to address when to use preventive antibiotics against infective endocarditis. The 2005 task force recommends that patients with a prosthetic valve or who have prosthetic material used to complete a valve repair, patients who have had a history of infective endocarditis, and any patients with a congenital heart defect should receive prophylactic antibiotic therapy prior to any dental work that involves manipulation of gum tissue.
References
- "Medical-Surgical Nursing-Critical Thinking for Collaborative Care"; Donna D. Ignatavicius and M. Linda Workman; 2006
- "American Nurse Today"; Mitral Valve Replacement or Repair; Kathleen Hill; May 2009
- "Journal of the American College of Cardiology": Guidelines for the Management of Patients with Valvular Heart Disease
