FEW FIELDS IN MEDICINE HAVE changed with the lightning speed of cardiology. In the not-so-distant past, doctors had only a stethoscope to listen to the beat and rhythm of a heart and make a diagnosis. Thirty years ago, though, everything changed: We learned how to thread catheters through blood vessels and take pictures of the heart while it was beating. As a result, we could watch the blood course from chamber to chamber, through the lungs, and to the rest of the body.
But every invasive procedure invites risks, and soon there was a call for safer techniques. Ultrasound, or echocardiography, in which sound waves are bounced off the heart, is one of the tools that have revolutionized the way we view the heart, enabling doctors to make diagnoses without putting tubes in the body. Now, the pictures come not only in color but with such astonishing clarity that we can literally peer behind valves and into nooks and crannies of the heart.
Doctors often become so enthusiastic about new technology that they use it alot, sometimes discovering maladies not seen before. Now, it appears, mitral valve prolapse (MVP) may have gained prominence in the medical literature precisely because of the improvements in echocardiography. Indeed, from the early seventies to the mid-nineties, it became the most common cardiac disorder diagnosed in young people, with at least 13 million and possibly as many as 30 million men and women suspected of having the problem.
Just what is the disorder? With MVP, the valve between two chambers of the heart–the left atrium and left ventricle–doesn’t snap shut and lock off the chambers. Instead, it’s “floppy,” allowing blood to swish back and forth. In mild cases, this means nothing, though doctors have worried that bacteria could live on a floppy valve; as a result, they have recommended that patients take antibiotics before surgery and even before having their teeth cleaned. In severe cases, if the valve is too floppy, there may not be enough blood in the ventricle for the heart to eject to the rest of the body, ultimately leading to heart failure. There was also concern that those with MVP would be prone to other health problems–infections or blood clots, for example–or that simple illnesses could become more complicated.
Now comes an article in the New England Journal of Medicine that tells those of us in the medical community to wait a minute. Researchers, after studying nearly 3,500 people, have found that MVP is not nearly as common as presumed. Far from affecting 5 to 15 percent of the population, as once thought, it seems that only 2.4 percent have the problem. What’s more, those people in the study who were diagnosed with MVP (and it was only 84 women and men) suffered from no more illnesses than those without the condition.
How could this happen? For one thing, the original numbers were based on university studies, which invariably include a more sickly patient population. These new estimates come from a cross-section of a normal group, participants in the famed Framingham Heart Study–an ongoing research project to identify risk factors associated with heart disease.
Also, I think the technology encouraged us to see more than was there. A patient might come into a doctor’s office complaining of shortness of breath, fatigue, or palpitations–signs of a heart-valve problem (but of many other conditions as well). And the doctor, seeing something on an ultrasound that didn’t look quite right, made a diagnosis of mitral valve prolapse. In short, MVP is the product of an era when technology was suddenly good … but not good enough. Today’s machines are astonishingly more accurate, making those from just a decade ago seem ancient. And so … the numbers aren’t as high as we’d thought.
What should you do if you have been diagnosed with MVP? First, check with your doctor and ask for a referral to a cardiologist who is up on the latest technology. Odds are great you’ll be cleared. But if the diagnosis is confirmed, you will need to continue to take a prophylactic dose of antibiotics before any surgery or dental session.