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Listen To Your Heart
Biomedical Scientists Develop Computerized Stethoscope To Analyze Heart Murmurs

March 1, 2007 — Scientists have developed a new tool that may eliminate unnecessary visits to a specialist by allowing doctors to examine and assess heart murmurs. The Zargis Acoustic Cardioscan first amplifies and records heart sounds. Then -- using mathematics -- computer software analyzes the heart sounds and graphically displays the murmur, helping doctors determine whether a patient's murmur is a sign of something severe.

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Heart disease is a leading killer for both men and women. That's why when we hear the words "heart murmur," our heart may skip a beat. But not all murmurs indicate disease. Now a new improvement to the old stethoscope will have doctors relieving your anxiety with just one visit.

The heartbeat signifies life. Since the 1800s, doctors have relied on the stethoscope to detect heart murmurs. Through a stethoscope, a murmur sounds like a swishing noise. To a patient, the diagnosis can be scary.

"A murmur is an abnormal heart sound that can sometimes signify a diseased heart valve," Alain Chaoui, M.D., a family practitioner at Family Medicine North in Peobody, Mass., tells DBIS.

Doctors detect murmurs in about 30 percent of all adults and 80 percent of children. Most are harmless, but the most common way to tell is through additional testing with an echocardiogram or with a visit to a cardiologist.

Now, biomedical scientists have developed a new computerized stethoscope that may eliminate that extra visit to a specialist's office. The Zargis Acoustic Cardioscan System first amplifies and records heart sounds. Then -- using mathematics -- computer software analyzes the heart sounds and graphically displays the murmur, helping doctors determine whether a patient's murmur is a sign of something severe.

"For a patient, right away it will diffuse the anxiety of having an abnormal heart sound," Chaoui says. He believes Cardioscan will also diffuse unnecessary insurance costs, now that he can diagnose murmurs on the spot. It has been authorized by the FDA and takes just minutes for a doctor to perform.

BACKGROUND: Doctors use stethoscopes to listen to heartbeats, but the results depend largely on the physician's interpretation. Some heart irregularities can be difficult to detect, such as heart murmurs. Cardioscan is a new computer-assisted stethoscope device designed to help primary care physicians analyze the wide range of heart murmurs, to better understand which murmurs are pathological and which are not. Cardioscan is now being used on an introductory basis by primary care physicians at centers around the country. Cardioscan is portable, easy-to-use and non-invasive.

HOW IT WORKS: With Cardioscan, the sound of the heartbeat is displayed graphically in order to help the physician determine which valve in the heart a murmur may be coming from, and how serious it might be. Each reading is recorded and stored and could be used as a baseline for follow-up visits. Sound waves are mechanical energy. Passing a coil of wire through a magnetic field will generate electricity within that coil, while passing electricity through a coil of wire will give rise to a magnetic field. A transmitter (such as that in a telephone) contains both a wire coil and a small magnet. Sound waves cause the coil to vibrate in response to the sound waves within a magnetic field. This turns the sound wave into an electrical signal, which can be transmitted to a computer. This data is then used to produce the graphical image.

BENEFITS: A 2005 clinical study measured the accuracy of a group of primary care physicians in evaluating a set of 100 recorded sounds. The heart sounds were independently evaluated by each physician without consulting Cardioscan. Then they were evaluated again with Cardioscan. The physicians were able to reduce their rates of unnecessary referrals by an average of 41 percent. So Cardioscan has the potential to result in greatly reduced costs, because more than 3 million patients are unnecessarily referred each year for an echocardiogram to test for heart murmurs. The study also showed a 46 percent reduction in false negative rates, so Cardioscan could also help save lives by helping physicians detect dangerous heart conditions.

Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.

Note: This story and accompanying video were originally produced for the American Institute of Physics series Discoveries and Breakthroughs in Science by Ivanhoe Broadcast News and are protected by copyright law. All rights reserved.