心臟病及保健 Heart Disease And Health http://心臟病.tw www.heartdisease.idv.tw
VALVULAR HEART DISEASE
Andrew Ying-Siu Lee, MD,PhD.
The heart is made up of left and right atria and ventricles. When the heart contracts (systole), the heart
valves (which divide the heart into four chambers) known as aortic and pulmonary valves open while mitral
and tricuspid valves close. On the other hand, when the heart relaxes (diastole), aortic and pulmonary valves
close while mitral and tricuspid valves open. Therefore the normal pumping action of the heart (systole and diastole)
depends on normal open-and-close action of the heart valves. When the valvular actions are abnormal,
there is abnormal heart function and then heart failure, leading to the so called valvular heart disease.
Valvular heart disease is common heart disease. The etiology include: (1) congenital valvular heart disease,
(2) degenerative valvular disease, (3) rheumatic valvular disease and (4) others such as infection, trauma,
systemic disease, endocrine and metabolic diseases, or other heart diseases affecting the valves.
The commonest valvular heart diseases are :-
(1) MITRAL AND TRICUSPID VALVE PROLAPSE : About 3-6% adult patients may have
genetic or environmental changes in the mitral or tricuspid valves and therefore thickening and collapse of
the valves associated with valvular insufficiency. Majority have no symptom and good prognosis, and need
medical follow up every two years. Occasionally, patients may have symptoms such as chest pain, palpitation,
shortness of breath, weakness, dizziness etc., which are easily relieved by medications. Very rarely, some
patients may have severe valvular collapses associated with severe valvular insufficiency leading to abnormal
heart function requiring surgical intervention.
(2) AORTIC STENOSIS : Common in the aged. Here the aortic valves become stenosed because of
degeneration, calcification or rheumatic involvement of the valves. The stenosed aortic valves may lead to
abnormal heart function, cardiomegaly, poor circulation. Because the disease progresses slowly, patients
seldom have symptoms and need medical follow up every year. But if symptoms become obvious, such as
chest pain, heart failure, syncope, the prognosis becomes poor and need surgical intervention. Without operation,
patients will die within 2 to 5 years. With successful operation, however, the prognosis is good.
(3) MITRAL STENOSIS : Because of rheumatic (majority) or genetic (minority) factors, the mitral
valves become stenosed leading to poor heart function, cardiomegaly, pulmonary arterial hypertension,
arrhythmias etc. The disease progresses slowly and patients slowly develop symptoms such as dyspnea,
pulmonary edema, pedal edema, weakness, palpitation, heart failure etc. Depending on the heart condition
(as assessed by doctors), cardiac catheterization with balloon valvuloplasty or surgical operation is needed.
Without operation, patients will die within 5 to 10 years. With successful operation, however, the prognosis is good.
(4) AORTIC INSUFFICIENCY : Etiology include: degeneration or calcification of valves,
rheumatic valvular disease, congenital valvular disease, infection, trauma, systemic diseases etc. Aortic insufficiency
will lead to poor cardiac output, cardiomegaly, pulmonary edema etc. Unless the aortic insufficiency is
acute in onset, the disease progresses slowly and patients usually slowly develop symptoms such as dyspnea,
chest pain, heart failure, dizziness, fainting, arrhythmias etc. Surgical intervention is needed if medically
refractory, abnormal heart function or acute onset aortic insufficiency. The 5 year mortality after successful
operation is about 15-30%.
(5) MITRAL INSUFFICIENCY : Commonly due to: mitral valve prolapse, rheumatic heart disease,
coronary artery disease, cardiomyopathies etc. Mitral insufficiency may lead to cardiomegaly, arrhythmias,
pulmonary arterial hypertension etc. Usually the disease progresses slowly and patients slowly develop
symptoms such as dyspnea, heart failure, dizziness, fainting, arrhythmias etc. Surgical intervention is
needed if medically refractory, abnormal heart function or acute onset mitral insufficiency. The 5 year mortality
after successful operation is about 30%.
(6) TRICUSPID INSUFFICIENCY: Secondary causes include: heart failure with pulmonary arterial
hypertension, pulmonary heart disease, right ventricular hypertrophy etc. Primary causes include: rheumatic
heart disease, trauma, endocarditis etc. Common symptoms include: dyspnea, right heart failure, dizziness,
fainting, arrhythmias etc. Medical treatment is usually successful. Rarely, patients may need surgical intervention
for very severe tricuspid insufficiency.
Therapy of valvular heart diseases include: (1) correct diagnosis and explore the primary or secondary
causes, assess the severity, and appropriate medications, (2) prevent and treat the complications such as
endocarditis, arrhythmias, thromboembolism, coronary artery disease etc., (3) treat the abnormal hemodynamics
so as to relieve symptoms and prevent worsening of diseases, (4) regularly follow up and assess the heart
condition so as to correct timing of surgical intervention. Patients should have good compliance, regular
examinations and medications. They should understand and avoid complications such as: (1) vaccination,
antibiotic prophylaxis before surgical interventions, personal hygiene so as to avoid infectious endocarditis,
(2) anticoagulants to prevent thromboembolic events and observe any bleeding tendency, (3) stop smoking,
diet control, regular exercise etc., (4) report to doctors immediately if symptoms occur or worsen.