DEAR DR. ROACH: I read your recent column regarding asymptomatic atrial fibrillation. How does this differ from having a heart murmur? I have had a murmur for about 25 years, though it was not fully diagnosed until three years ago during an unrelated emergency room visit. Until recently, the murmurs were getting worse. Other than limiting my intake of caffeine, is there anything I can do? — G.K.
ANSWER: Atrial fibrillation is an abnormal heart rhythm, an electrical disturbance of the heart. A murmur is a mechanical issue.
A heart murmur is a sound that’s heard by the examiner, most commonly of blood flowing through one of the heart valves. Often, the murmur is not due to any problem: In a thin person, blood can sometimes be heard through a normal valve. Other times, a heart murmur may be the sign of a damaged valve. Either the valve isn’t opening all the way, called stenosis; or the valve fails to close properly and the blood flows the wrong way across the valve, called incompetence, insufficiency or regurgitation. Rarely, a murmur can be heard through a structure that should no longer be open, such as a patent ductus arteriosus — necessary in fetal life to allow oxygenated blood from the placenta to flow into the developing fetal body.
Many times, a correct diagnosis of the underlying cause of a heart murmur can be made by examination. Other times, further evaluation is warranted. An echocardiogram uses sound waves to take pictures of the heart and measure the direction and velocity of flow. Severely diseased valves, from stenosis or incompetence, may eventually need valve replacement.
Most heart murmurs do not require treatment and shouldn’t make you worried. Your regular doctor or cardiologist should be able to tell you whether yours is the kind that needs to be kept an eye on or if you can ignore it. Caffeine intake is not a problem for people with heart murmurs.
Physicians hear heart murmurs so often that we can forget that the term can be concerning to people who are just hearing they have one and suspect it means a serious heart problem, which it usually does not.
DEAR DR. ROACH: To listen to the heart or lungs, some practitioners place the stethoscope on the patient’s skin; others place it on the outside of the patient’s clothing. I would appreciate your comments on how the two techniques compare. — B.L.
ANSWER: Directly on the patient’s skin allows for the best sound transmission. When listening to a very soft heart murmur, having a quiet room and the patient’s chest completely exposed is necessary. However, a thin garment, such as a T-shirt or a hospital gown, doesn’t create a large loss of sound. Thicker garments make listening to the chest considerably less effective, so that an examiner may only be able to hear very significant abnormalities.
I teach my students to have a patient disrobe entirely. Sometimes, physicians take shortcuts for the sake of time, but it does come at a cost of accuracy.