September 18, 2012 > Irregular Heartbeat - Is it a serious health threat?
Irregular Heartbeat - Is it a serious health threat?
The normal human heart beats an average of 72 times per minute. That means, if you are able to stay healthy and live to be 80 years old, your heart will beat more than 3 billion times during your lifetime. Your heartbeat is responsible for the flow of blood throughout your body.
As your heart beats, blood is squeezed from its two upper chambers, called atria, to its two lower chambers, called ventricles. If the squeezing rhythm between the upper and lower chambers gets out of sync and stays that way, the condition is called atrial fibrillation, or "AFib," which can cause serious health problems.
"We all experience an irregular heartbeat now and then, and that is nothing to worry about," explained Ash Jain, MD, a board certified cardiologist on the medical staff at Washington Hospital and medical director of the Hospital's Stroke Program.
"With atrial fibrillation, blood can sometimes stagnate and pool in the upper chambers of the heart. When that happens, blood clots can form, putting you at risk for a stroke or other serious problem involving your circulatory system."
According to the American Heart Association (AHA), an estimated 2.7 million Americans have atrial fibrillation. "It's the most common serious heart rhythm abnormality in people over the age of 65," reports the AHA.
The problem is that many people don't consider AFib a serious ailment. In 2009, a nationwide survey revealed that only 33 percent of AFib patients thought they had a serious condition, and less than half believed they were at increased risk for stroke or other life-threatening disorders.
A blood clot that forms in the heart, as can happen with atrial fibrillation, is called a thrombus. If the thrombus breaks free and travels through the bloodstream to other areas of the body, it is called an embolus. An embolus can potentially block arteries that supply blood to the brain, kidneys, gastrointestinal system and legs. When blood flow is interrupted, serious tissue damage, and possibly even tissue death, can occur. Atrial fibrillation that goes untreated can also weaken the heart muscle itself, which can lead to heart failure.
Patients who are in constant atrial fibrillation, can be easily diagnosed by having an electrocardiogram. If the condition is intermittent, called paroxysmal atrial fibrillation, diagnosis is more difficult. One way is to use a holter monitor, which is a portable machine that records heartbeats while a person wears the monitor under their clothing throughout the day. The individual presses a button if they feel symptoms, and the heartbeat is recorded. Another diagnostic device, called an event recorder, records all the beatings of the heart and can be worn continuously for up to a month. There are additional new technologies that help to diagnose paroxysmal atrial fibrillation.
Once atrial fibrillation has been diagnosed, a treatment plan is developed to help manage the problem. This can include thinning the blood so that blood clots don't form, getting the heart back to its normal rhythm, and taking steps to prevent heart failure or advancement of the condition.
Medications can be used to help thin the blood so clots won't form. One challenge in using blood thinning medications is that the risk of bleeding must be balanced against the danger of further clot formation.
"If we don't thin the blood, the risk of stroke is 8 percent to 10 percent," said Dr. Jain. "With blood thinners, the risk of bleeding is 4 percent to 5 percent."
Certain people are at higher risk of blood clots and stroke from atrial fibrillation. A classification system has been developed to identify the level of risk in these individuals so doctors can best decide whether to thin the blood. The tool is called CHAD2 and takes into account whether a person is in congestive heart failure (C), has high blood pressure (H), is older than 75 (A), has diabetes (D), or has a history of insufficient blood flow to the brain, which is doubly weighted (2). Each factor is given a point value, and a patient's total point count helps doctors assess their level of risk for stroke.
One way doctors can help get the heartbeat back in sync is with cardiac ablation. In this procedure, long, slender tubes called catheters, with electrodes at their tips, are inserted into the heart through blood vessels in the arm, groin or neck. Then, radiofrequency energy is applied to destroy abnormal tissue that contributes to the cause of the irregular rhythm.
The most important thing to remember about atrial fibrillation is that it should be diagnosed early and managed properly. If you or someone you know is experiencing heart palpitations, feelings of an irregular heartbeat, or other heart problems, you should see a cardiologist and an electrophysiologist, a doctor who specializes in the electrical aspects of the heart. These specialists can help to prevent the potentially disastrous consequences of atrial fibrillation.