How is valvular heart disease diagnosed?
There are various ways by which your doctor can diagnose heart disease.
Physical examination: The most common manifestation of valvular heart disease is heart murmur, a noise that occurs when the blood passes through a particular valve. Ordinarily, passage of the blood through a heart valve is so smooth that a physician cannot detect any murmur when he listens to the chest of a patient through the stethoscope. It should be noted that not all heart murmurs necessarily represent valvular heart disease. Approximately 10% to 20% of heart murmurs are innocent and are termed benign heart murmurs. Many times, these heart murmurs disappear as age advances, and even if they may persist, they may not cause any heart problem. Occasionally, heart murmurs can occur in the absence of valvular heart disease, such as pregnancy, anemia, or thyrotoxicosis (excess thyroid hormone production).
Echocardiogram: Echocardiogram (heart ultrasound) has revolutionized diagnosis of valvular heart disease. This very simple and mostly noninvasive test does not only accurately detect valvular heart disease but also can define its severity and prognosis and direct appropriate management. An additional recently added feature to sonographic examination of the heart is called Doppler study. This method works through pressure principles of physics and adds to the accuracy of sonographic evaluation. A color component added to Doppler studies can actually visualize the blood flow through various heart valves. Serial echocardiographic evaluations (semi-annually or annually) can help judge progress of the disease and/or can help determine optimal time for intervention. This painless, noninvasive procedure also allows the cardiologist to determine heart pump function. Progress in science of echocardiography is continuous, and even 3-dimensional echocardiography is not far from reality. Trained technologists known as cardiac sonographers perform the procedures, and the cardiologist interprets them.The procedure itself lasts for 30-45 minutes and has become widely available throughout the United States.
Cardiac catheterization: This is an invasive procedure performed by introduction of a catheter generally through a peripheral vein and/or artery in the groin (known as the femoral vein and the femoral artery). Although diagnostic in nature, these procedures are generally performed prior to intervention (for example,prior to cardiac valve surgery). Although invasive, these procedures are generally considered safe, and the complication rate is below 0.5% when performed by experienced operators. The procedure is similar to a coronary angiogram; the difference is the catheters enter the heart chambers in cardiac catheterization. Valvular diseases are detected through direct inspection (visualization) and pressure measurements. It is, at least at the present time,considered the "gold standard." This procedure has also been described in detail elsewhere in the book.
What happens once heart valve disease is detected?
Treatment of heart valve disease depends upon the patient's clinical status (symptoms and signs), severity of valvular heart disease, and expected outcome after its treatment. Most often, valvular heart diseases require surgery for their correction. These procedures are known as heart valve replacements.
Technology has, however, advanced. In some instances, particularly in mitral and tricuspid valves, repair valvular surgery can also be undertaken. As a matter of fact, these repair procedures are gaining more acceptance because they preserve the natural integrity of the heart valves. Furthermore, anesthesia and perioperative care have improved considerably, adding a new level of safety to these procedures. Even though heart valve replacement requires open-heart surgery, the morbidity/mortality rate (death rate) remains acceptable and varies between 2% to 10%, depending upon the patient's condition and co-existent problems.
Currently, nonsurgical treatment of certain heart valves is being attempted and is still in the experimental phase. Percutaneous (via catheterization techniques) methods are being developed where valves can be replaced or repaired without surgery. It will be several years before these techniques are validated and become available.
What are the types of heart valves?
There are 2 types of heart valves. The first category is mechanical heart valves. These are also known as "metal" heart valves.The second category is bioprosthetic ("tissue") heart valves. Commonly, these are also referred to as "pig valves." A cardiovascular surgeon would determine what kind of heart valve one should get. Although both categories of heart valves have performed very well throughout the years, there are some differences between these categories. The foremost difference is the lifetime of the heart valve. Metal heart valves generally last longer compared to tissue heart valves. On the other hand, mechanical (metal) heart valves require anticoagulation (thinning of the blood), generally through the use of the drug warfarin (Coumadin).
Many factors enter into consideration while determining the type of heart valve to be used. For example, if valvular heart surgery is chosen in the older age group and when use of Coumadin is thought to be associated with high risks, bioprosthetic (tissue) valves are chosen. The converse may be true for younger individuals.
What can one expect after valvular heart surgery?
The most important factor in determining the outcome of valvular heart surgery is optimal timing. Therefore, it is of paramount importance that the patient follow-up with his or her cardiologist in a very regular fashion once heart valve disease is detected. The patient's functional status, physical examination, serial echocardiographic evaluation, cardiac catheterization, and other factors may determine the need for surgery. One such other factor can be pregnancy. Because pregnancy imposes additional stress on circulation, physicians may decide to undertake valvular heart surgery prior to pregnancy and delivery.
One may expect quite a good prognosis after heart valve surgery. Improvements would include not only better functional status (that is, the ability to perform ordinary activities) but also overall survival prognosis.
Because valvular heart diseases take months and years for their full adverse effects, it may take some time (usually more than 6 months or a year) before a patient would fully recognize the benefit of surgery. Periodic checkups are a necessity, even after successful surgery.
What is prophylactic antibiotic?
In medical terms, administering antibiotics to prevent infection on the heart valves is known as prophylaxis for subacute bacterial endocarditis (SBE). The presence of valvular heart disease (even after surgery) mandates that the patient receives appropriate antibiotic(s) prior to undergoing certain procedures (such as dental procedures or other surgeries) or prior to anticipated infections. The American Heart Association has published appropriate guidelines for this purpose. However, it is of utmost importance that the patient keeps the dentist or other physician(s) informed of the nature of his or her heart valve disease.
Heart valve diseases are generally chronic and progressive in nature. However, they may occur acutely as well. Notable examples are after heart attack or after acute infections. Generally, surgery is needed for severe valvular heart diseases for optimal outcome. However, medical therapy is also carried out most often as adjunct therapy. It should not be forgotten that once it occurs, valvular heart disease is a life-long process. Therefore, it is vital that it be followed by an appropriate physician (generally a cardiologist) throughout its course.
Significant progress has been made in this category of heart diseases during the last half century, and progress continues. Once thought relentless and progressive, these diseases can be prevented and appropriately cared for by the progress that the science of cardiology has fulfilled through many last decades.
