SATURDAY, June 16, 2001 (HealthDayNews) -- Although some people can be too sensitive to the body's assorted sensations, even the faintest feeling of a skipped heartbeat can throw stalwart souls into a tizzy.
But experts say such heart "thumps," known as premature ventricular contractions (PVCs), are common and usually benign.
"When we do 24-hour recordings of people's EKGs (electrocardiograms), it's more common than not that the patients have at least one or more PVC," says Dr. Richard Stein, chief of cardiology at the Brooklyn (N.Y.) Hospital Center.
In fact, Stein, a spokesman for the American Heart Association, says, a recent study of EKGs conducted on members of the Brooklyn College swimming team showed that almost all the young swimmers had at least one PVC.
Although they may feel like "skipping" or palpitating heartbeats, PVCs are actually early heartbeats, as the name describes.
"The beat comes early enough in the cardiac cycle that it doesn't produce a full cardiac contraction of normal strength," explains Dr. Jeanne Poole, associate professor of medicine in the division of cardiology at the University of Washington School of Medicine.
"It seems like a skipped beat because it may feel like a pause surrounding the early beat," she says.
Doctors link PVCs to everything from drinking too much coffee or taking over-the-counter medications, to thyroid problems, stress or lack of sleep.
But the specific causes are somewhat more ambiguous, Stein notes. "In general, there are a number of physiological explanations as to why these occur," he says.
"The biological system is obviously not hard-wired like your wall clock," Stein says. "There are always changes going on in our cells and conduction systems, and it's common to see these kinds of events."
Despite the fact that, in small numbers, PVCs are usually harmless, not all of them should be ignored -- particularly if they come in "multiples" or are accompanied by other symptoms, Stein says.
"We get interested if they bunch together in something like more than three in a row, if they're profound, and occur with every other beat," he says.
"And they're considered more important in the context of the company they keep -- if they're in the presence of muscle dysfunction or other electrical problems in the heart or severe narrowing of the arteries of the heart. Then they can be harbingers of serious events and need to be addressed as such," Stein adds.
Symptoms that demand immediate medical attention include dizziness, lightheadedness or passing out after what feels like a series of skipped beats, Poole says.
"Most of the time it is benign," Poole adds, "but you don't want to miss the few percentage of times it's not. So that's why we always say, if it's something new, you should always have it checked out."
PVCs are different from heart-attack symptoms because they only last a moment. Heart-attack symptoms tend to last longer and include chest pressure, shortness of breath, sweating or nausea.
What To Do: Read more about heart health in these HealthDay stories. Or visit the American Heart Association for more information on PVCs.
