Learn About Your Heart...
Made Simple


By Nicolas Shammas, MD


A new, comprehensive sourcebook for
heart and vascular disease patients

Cardiovascular Health Topics



1.
Statistics about Heart and Blood Vessel Diseases in the United States
2.
Structure and Function of the Heart and Blood Vessels
3.
Diseases of the Blood Vessels of the Heart
4.
Surgical Therapies for the Cardiovascular Patient
5.
Peripheral Vascular Disease
6.
Diseases of the Blood Vessels of the Head and Neck
7.
Strokes: How to Survive Them and How to Prevent Them
8.
Valvular Heart Disease
9.
Heart Rhythms: How to Recognize Them and Treat Them
10.
Congestive Heart Failure
11. Understanding Cardiomyopathy, or Weak Heart Muscle
12. Children and Heart Disease
13. Diseases of the Pericardium
14. Systemic Illnesses, Infections and Drugs that Affect the Heart
15. Erectile Dysfunction: a Vascular Disease
16. Cardiovascular Disease Prevention
17. Heart Healthy Nutritional Tips
18. Cardiac Rehabilitation
19. Medications for Cardiovascular Disorders
20. Heart Tests You Need to Know
21. Learn What to Do in a Medical Emergency
22. How to Choose Your Doctor and Hospital
23. Medical Research and How You Can Get Involved
24. Taking the Next Step — A Few Community Resources to Help You Live More Healthfully
25. How Much Did You Learn from This Book: Take a Simple Test



VALVULAR HEART DISEASE

Girish R. Bhatt, MD, FACC, FACP

What are heart valves?

The heart is a machine, a pump, and like any other pump, for the heart to work efficiently, it needs valves. Heart valves are basically designed to regulate the amount, direction, and appropriate flow of blood so that body organs receive proportionate blood, a vehicle to supply nutrients to various organs. Despite the fact that heart valves are very delicate structures, nature has designed them in such a way that ordinarily they function well throughout human life. Heart valves are so delicately and accurately placed within the heart structure that they coordinate their function with efficiency of the heart pump in a totally optimal manner. However, the complexity of their structure makes them vulnerable to many damaging processes, such as degeneration, infection, inflammation, or congenital deformities.

Where are the heart valves located?

Basically, there are 4 heart valves: 2 in the left side and 2 in the right side of the heart cavity. The heart valve that is located between the left upper heart chamber and the left lower heart chamber is termed the mitral valve. The left upper chamber is called the left atrium, and the left lower chamber is called the left ventricle. The heart valve that is located between the main left chamber (left ventricle) and the main body artery (aorta) is called the aortic valve. The heart valve located between the right upper chamber (right atrium) and the right lower chamber (right ventricle) is called the tricuspid valve. The heart valve located between the right lower chamber (right ventricle) and the pulmonary artery (main lung artery) is called the pulmonary valve.

How do heart valves function?

The basic function of the heart valves is to allow passage of blood to the heart chambers and from the heart chambers to the body and lungs. Heart valves operate through pressure changes between 2 adjacent chambers and vessels. For example, when the left lower chamber (left ventricle) contracts, pressure within the cavity increases, which opens the aortic valve.

On the other hand, when the left ventricle relaxes, pressure within its cavity falls below that of the aorta (distal vessel), and that closes the aortic valve. Similar pressure changes occur across other valves, which open and close appropriately. A normal valve structure is vital to the opening and closing of the heart valves.

How does valvular heart disease occur?

Two principal ways in which valve dysfunction can occur are known as stenosis (narrowing of the heart valve) and regurgitation (leakage of the heart valve). For example, aortic stenosis means that the aortic valve is narrow; therefore, it will not allow the appropriate amount of blood to go from the left ventricle to the aorta. It will also imply that the left ventricle will have to work much harder (and, hence, spend much more energy) to let the blood go through the aortic valve. Aortic regurgitation means that blood is leaking backward from the aorta to the left ventricle.The same terminology is applied for the mitral valve, tricuspid valve, and pulmonary valves.

There are various ways through which valvular dysfunction can occur:

  • Congenital heart disease: An inborn error in the structure and function of the heart valve, this disease is generally secondary to developmental malfunction and gets detected at a very early age.Advances in pediatric cardiology have made prognosis of congenital heart disease significantly better.

  • Infection: The first notable cause of valvular disease by infection is rheumatic fever. A very common disease of the last century and the earlier part of the 20th century, rheumatic fever has vanished quickly through our ability to eradicate infection. However, this still remains a real health problem, primarily in underdeveloped countries. In adult life, infections like those caused by bacteria can result in valvular heart dysfunction; medically, this is known as bacterial endocarditis. However, it is very uncommon for a normal heart valve to get infected. Generally, secondary heart valve infections occur in patients who have been suffering from congenital or rheumatic heart diseases. Rheumatic fever is caused by infection from bacteria known as streptococci. Primary manifestations of this infection consist of fever and multiple joint pains. These bacteria can also cause a disease known as scarlet fever.

  • Structural valvular heart disease: Mechanically, heart valves are appropriately sized for the cavity in which they are located. If for any reason a cavity becomes enlarged disproportionate to the size of the heart valve, heart valve dysfunction (particularly leakage) of that valve can occur.

    Enlargement of the heart can occur through various mechanisms that cause heart failure,infection in the myocardium (heart muscle), and sudden acute processes, such as heart attacks.

  • Various other mechanisms: Valvular dysfunction can occur through various other mechanisms including fibrosis and calcium deposits (aging process) and other rare processes, such as myxomatous degradation (abnormal substance deposition in heart valve) or certain weight-loss drugs.

How does valvular heart disease affect the human body?

The ultimate adverse outcome of valvular heart disease is heart failure. However, it may take a long time (sometimes years) before overt manifestations of heart failure occur after onset of valvular heart disease.

What are the symptoms of heart failure?

The main symptoms of heart failure are fatigue (tiredness), dyspnea (shortness of breath), and edema (swelling of the feet). The patient may experience lack of vigor and vitality and/or may simply not feel as well as before.

Heart failure can worsen or can be worsened by other co-existent conditions, such as anemia (low blood count) and pregnancy.


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