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Cardio-vascular Health

Heart Murmur, Mitral Valve Prolapse

Some Murmurs are like the swinging doors of a Western Saloon

By Dr. W. Gifford Jones

November 3, 1991

What is a well patient? It's been said, only partly with tongue in cheek, that "It's a patient who hasn't been examined by enough doctors". One could add, "and hasn't been tested by enough electronic equipment". This column attempts to explain why some progress in medical diagnosis is a mixed blessing. How it scares some patients half to death when they're informed a heart murmur is present. Or that they have a condition called mitral valve prolapse (MVP).

A heart murmur is simply the sound of a turbulent flow of blood through the heart. Blood flowing through the heart normally doesn't make any sound. Doctors usually hear only the regular "lub dub" beat of the heart. But when a so-called "murmur" is present, they are also hearing a "whooshing" noise.

Not all heart murmurs are of significance. For instance, athletes and pregnant women exhibit an increased volume of blood passing through the heart which causes a physiological murmur of no importance. Similarly, many heart murmurs in young children often taper off with time and completely disappear in their thirties.

Heart murmurs in the elderly may or may not be of importance. There's no need for concern if the murmur is due to thickened heart valves. But if it is associated with a narrowed valve this can indicate trouble.

Certain clues help doctors determine if a murmur is pathological. Systolic murmurs are often innocent, physiological murmurs normally caused by the pumping of the heart. Systolic murmurs, however, can be serious when the valve is narrowed.

Diastolic murmurs, heard while the heart is relaxed, are always due to disease. In the past these murmurs were usually related to a previous attack of rheumatic fever. Today, with an aging population doctors see an increasing number of patients with diastolic murmurs that are due to degeneration of the valve.

But medical progress in categorizing heart murmurs can be a mixed blessing for patients. Sophisticated tests such as echocardiograms has enabled doctors to detect murmurs due to "mitral valve prolapse" or what is commonly referred to as a "mitral click". Patients told they have MVP don't sleep well unless they're given a full explanation of this diagnosis.

Physicians have heard this "click" for years, but never became too excited about it. The patients seemed generally to be healthy and they believed the sound originated beyond the heart somewhere in the chest cavity. They also noted the clicking sound was usually heard in tall, slender patients with relatively long arms and a flat rib cage. And it was found more often in women.

The mitral valve separates two main chambers of the heart. And a floppy one is similar to the swinging door of an old western saloon. Its hinges are a bit too long. This allows the valve to swing back into the chamber of the heart when blood is forced through it.

Physicians debate whether it's wise to tell patients they have MVP. Some argue it worries patients for no good reason. After all, we don't make a point of telling patients they have a crooked nose. So why concern them about a slight variation in the architecture of the heart.

Besides is it reasonable to label MVP a disease when a large percentage of the population reveal this finding? A report from The Harvard Medical School claims that 5 per cent of North Americans have MVP. But another study of 107 medical workers showed that 10 per cent had MVP when examined with a stethoscope. But when they were examined with an echocardiogram this figure jumped to 21 per cent.

Other physicians contend patients should be told they have MVP. They worry that a deformed valve has a greater chance of becoming infected with bacteria (bacterial endocarditis) during dental and other minor surgical procedures. And that patients should be advised to take antibiotics to prevent this potential problem.

They also claim that on rare occasions patients with MVP suffer episodes of chest pain, palpitations, fatigue, dizziness and shortness of breath. Not all doctors agree, however, that these symptoms are directly related to this condition.

Patients with pathological murmurs may never require treatment beyond the use of antibiotics for dental work or surgery. Others with badly diseased valves will require heart surgery to repair or replace the damaged valve.

But if you are told you have MVP there's no need to become a cardiac cripple or rush to draw up a new will. I doubt that nature has yet produced the perfect human. As Alexander Pope wrote in 1711, "Whoever thinks a faultless piece to see, thinks what ne'er was, nor is, nor e'er shall be."


W. Gifford-Jones M.D is the pen name of Dr. Ken Walker graduate of Harvard. Dr. Walker's website is: Docgiff.com

My book, �90 + How I Got There� can be obtained by sending $19.95 to:

Giff Holdings, 525 Balliol St, Unit # 6,Toronto, Ontario, M4S 1E1

Pre-2008 articles by Gifford Jones
Canada Free Press, CFP Editor Judi McLeod