Atrial Fibrillation (AF)
In some people, the rapid heartbeat caused by hyperthyroidism can lead to a dangerous condition called atrial fibrillation. AF is the most common abnormal rhythm of the heart. The problem originates in the atria, the two upper chambers of the heart, where the contractions dictate the amount of blood that gets pumped through your body.
In healthy people, the heart beats and pumps blood with regular rhythm, usually at a rate of about sixty beats per minute. Sometimes, like when you're exercising, it beats faster. Other times, during sleep for instance, it's considerably slower. But in healthy people, the interval between heartbeats is always the same, thanks to regular electrical discharges that travel through the heart and cause contractions. These impulses originate in the atria, then travel to the ventricles, where blood is pumped. We feel this steady pumping in our pulse. In people with atrial fibrillation, these intervals become irregular because the electrical discharges have become uncoordinated and rapid. The abnormal impulses travel to the ventricles of the heart, causing them to beat irregularly.
Alert
Caffeine, alcohol, and stress can all make atrial fibrillation (AF) worse. If you have AF, nix the morning java, skip the after-dinner drinks, and take steps to minimize your stress levels. You should also steer clear of over-the-counter cough and cold remedies that contain pseudo-ephedrine, which can stimulate the heart.
AF affects about 2.2 million Americans. Many factors can lead to AF. High blood pressure, thyroid disorders, heart disease, and alcoholism are just a few of the risk factors for AF. The risk for developing AF also goes up with age. Experts estimate that the condition affects 3 to 5 percent of people over the age of sixty-five.
Many people with AF have no symptoms and are unaware of the abnormality in their hearts. Those who do experience symptoms may feel palpitations. Other symptoms include dizziness, fainting, weakness, fatigue, shortness of breath, and angina, chest pain caused by reduced blood flow to the heart. These symptoms are the result of less blood being delivered through the body. In some cases, your first symptom is a stroke.
The Thyroid Link
AF can be the result of hyperthyroidism, which can set off the heart palpitations and a rapid heartbeat. If you have AF, you'll need more than just treatment to correct the thyroid problem. You'll also need medication to slow the rapid heart rate, such as beta-blockers or calcium-channel blockers, as well as anticoagulants to prevent clotting. Although rare, AF can also occur in people being treated for hypothyroidism who take too much thyroid hormone replacement.
Why It's Bad
In people who have AF, the atria may quiver, causing blood inside the atria to pool and clot. If a piece of a blood clot in the atria leaves the heart and becomes lodged in an artery in the brain, you will have a stroke. In fact, about 15 percent of strokes occur in people with AF. AF also increases your odds for heart failure.
