HEALTH MATTERS
By: Dr. Elliott Krauss
February is National Healthy Heart Month.
According to the American Heart Association, almost five million Americans currently live with congestive heart failure, with over half a million new cases being diagnosed each year. A person age 40 or older has a 1-in-5 chance of developing it.
Congestive heart failure occurs when the heart is unable to supply the body with enough blood. With this decrease in heart function, the body begins to feel fatigued, making even everyday activities, such as walking, going up stairs, carrying packages or doing yard work, difficult.
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As a result of the heart’s inability to pump blood to the body, the blood and its fluids back up into the lungs, interfering with the transfer of oxygen from the air into the bloodstream. All of these effects can result in shortness of breath even with mild exercise. The fluids can even continue down into the legs, causing a condition known as pedal edema (swollen ankles).
Heart failure is often a chronic condition that can affect anyone from young children to senior citizens. In most cases, an underlying problem such as clogged arteries (atherosclerosis), a defect in the heart’s walls or valves, or high blood pressure has weakened the heart over time. Although some patients do not experience shortness of breath, for the majority of patients, it is the major symptom.
When shortness of breath appears as a symptom, the AHA notes classifications, ranging from bad to worse. They include experiencing it:
with mild exercise, lasting through the exercise and an hour or so after;
with moderate to severe exercise, lasting through the exercise and an hour or so after, or
while at rest or lying down at night.
If a patient experiences shortness of breath while lying down, it means that fluids that have backed up and been pulled down into the legs during the day have backed up into the lungs. This is the worst-case scenario.
When it comes to diagnosing congestive heart failure, medical progress has resulted in a new test that was recently approved for use in hospitals.
The B-type Natriuretic Peptide (BNP) test is a simple blood test that is easy, requires little instrumentation, and yields results in 20 minutes. BNP is a hormone that is always present in the body and gets secreted from the ventricles of the heart in direct response to labored heart function. The hormone works to combat the effects of congestive heart failure by decreasing the kidney’s reabsorption of sodium and dilating the blood vessels all around the body.
Acting as a functional test, BNP levels indicate how well the heart is functioning. This marks the first time that there is a simple test that can detect heart failure. BNP replaces several other less sensitive tests, such as a chest X-ray, as the physician’s premier diagnostic tool.
BNP is proving particularly useful in emergency rooms. Because BNP has a very high specificity, meaning that if it is negative, there is a high probability that the patient does not have congestive heart failure, it is useful in directing patient care. If heart failure is not present, the physician will then consider other diseases, such as Chronic Obstructive Pulmonary Disease, which includes emphysema and chronic bronchitis diseases that are characterized by air flow difficulties.
If the BNP levels indicate heart failure, the most common cause is ischemic heart disease. To understand this major component of heart failure, it is helpful to understand how the heart functions.
The heart has a blood system all its own, supplying blood through these vessels to its muscle. If the vessels get clogged (called "hardening of the arteries" or, more technically, atherosclerosis), the oxygen-carrying blood is unable to get through, so the heart gets fatigued.
When the heart is unable to maximally contract and push blood around to the rest of the body, the fluids contained in the blood may back up into the lungs. This condition is commonly referred to as "water in the lungs" or "pulmonary edema." If the arteries get totally clogged, then the heart muscle gets no oxygen and dies. This is known as a heart attack or myocardial infarction.
BNP test results also guide a physician’s concern and treatment for the patient who has already experienced a heart attack. The higher the level of BNP during or shortly after a heart attack, the worse the prognosis. Likewise, if BNP levels remain elevated several days after a heart attack, the physician may caution the patient that there is an increased likelihood of other heart attacks or even death occurring within 18 months.
Although patients are generally not cured of heart failure, modern medical treatments can alleviate many of the symptoms. Fortunately, the heart often responds to treatments including medications; diet and other lifestyle changes; stress reduction and, in some cases, surgery.
It is imperative that people do not tolerate shortness of breath, compensating for it by restricting their activities or dismissing it as a sign of age. The patient who is experiencing shortness of breath or edema should seek medical attention before the symptoms become too severe.
Dr. Elliot Krauss is a pathologist who serves as Director of the Laboratory at The Medical Center at Princeton, where BNP testing is available. This article is prepared in collaboration with Lorraine Seabrook.

