Your heart relies on electrical impulses to keep it beating at a steady pace. Problems with this electrical system can cause abnormal heart rhythms, or arrhythmias. Thedefective impulses may cause the heart to beat too slowly or too fast, or tobeat in a disorganized and chaotic manner. Some of these different types ofarrhythmias can be incredibly dangerous if not properly treated, while othersmay be annoying but are not life-threatening.
1. Atrial Fibrillation
The most common type of arrhythmia, atrial fibrillation, affects about 2.7 millionpeople in the United States, according to the American Heart Association. Atrialfibrillation occurs when the heart’s upper chambers (the atria) begin to beatrapidly and irregularly. The condition itself isn’t life-threatening, but itincreases the risk for stroke by allowing blood to pool and clot inthe atria — increasing risk fivefold, says Hugh Calkins, MD, an electrophysiologist anddirector of the Cardiac Arrhythmia Service at Johns Hopkins Medicine inBaltimore.
Atrial fibrillation risk is lower before age 50 but then steadilyincreases with age. Blood thinners and medication to steadythe heart rate and rhythm are mainstays of treatment. In some cases, a specialprocedure called an ablation, which purposely scars thedefective part of the heart to prevent it from passing on unwanted signals, maybe recommended.
Tachycardia occurs when your heart suddenly starts beating very fast. Ifit happens as a result of exercise, excitement, or fever, it’s usually not acause for concern and doesn’t need treatment. But one type of arrhythmia calledparoxysmal supraventricular tachycardia (PSVT) is more dangerous. It createsextra heartbeats because electrical signals that move from the heart’s upperchambers to its lower chambers tend to loop back around to the upper chambers.This condition can cause sudden cardiac arrest if it affects the heart’s lowerchambers, but it’s curable through ablation. Tachycardia is most common inchildren and young people, and is more common in women than men.
3. Ventricular Fibrillation
Ventricular fibrillation is the most deadly type of arrhythmia. It occurswhen the lower chambers of the heart (the ventricles) begin to quiver insteadof pumping normally. Because these chambers handle most of the heavy liftingfor the circulatory system, ventricular fibrillation causes blood flow to verynearly cease. “If it’s not shocked in a timely fashion — and we’re talkingminutes — then the patient will die,” says Gordon Tomaselli, MD, professor of medicineand chief of cardiology at Johns Hopkins Medicine in Baltimore.
Ventricular fibrillation usually happens in people with some sort ofunderlying heart condition. Those at risk can be treated with medication or an implanted defibrillator that will shock theheart if it stops beating.
4. Premature Beats
Most irregular heart rhythms involve extra or skipped beats. These typesof arrhythmias are harmless and usually don’t cause symptoms. People who dofeel symptoms report fluttering in the chest or a feeling that their heart hasskipped. Premature beats can occur in anyone, most often happen naturally, anddon’t require treatment. But they also can happen as a result of heart disease,stress, overexercising, or too much caffeine or nicotine. In those instances,you should talk with a cardiologist about your heart and any needed lifestylechanges.
Bradycardia is a type of arrhythmia that, for many people, is no big deal.It means your heart rate is slower than normal — fewer than 60 beats a minutefor adults. Young people and others who are very physically fit may experiencebradycardia because they’re in good shape, and for them it isn’t dangerous anddoesn’t cause symptoms. But people can also have bradycardia if they’ve had a heart attack or if an underactive thyroidgland or aging has slowed the heart. In these situations, taking medication orhaving a pacemaker implanted may be needed.
Bradycardia can also occur because of a nutritional imbalance. If this isthe cause, your doctor may recommend a dietary supplement. In addition, thecondition can be a side effect of medication, and in those cases a doctor mayadjust your prescription.
6. Long QT Syndrome
A number ofother disorders occur because of problems with the heart’s electrical system.Long QT syndrome, a hereditary disorder that usually affects children or youngadults, slows the signal that causes the ventricles to contract. Anotherelectrical signal problem, atrial flutter, happens when a single electrical wavecirculates rapidly in the atrium, causing a very fast but steady heartbeat.Heart block involves weak or improperly conducted electrical signals from theupper chambers that can’t make it to the lower chambers, causing the heart tobeat too slowly. These conditions can put you at risk for cardiac arrest.Treatment might involve medication, ablation, or an implanted device to correctthe misfiring, such as a pacemaker or defibrillator.