Arrhythmia

An arrhythmia is any abnormality in the timing or pattern of your heartbeat. Your heart normally beats in a regular, coordinated rhythm — controlled by electrical signals that travel through the heart muscle in a precise sequence. When these electrical signals are disrupted, delayed, or take abnormal pathways, the result is an arrhythmia: your heart may beat too fast (tachycardia), too slow (bradycardia), or with an irregular pattern.

Not all arrhythmias are dangerous. Occasional extra heartbeats (premature contractions) are extremely common and usually harmless — most people experience them from time to time, often described as a fluttering or skipped-beat sensation. However, some arrhythmias can be serious, reducing the heart's ability to pump blood effectively or increasing the risk of blood clots, stroke, or sudden cardiac arrest.

Arrhythmias can be caused by heart disease, electrolyte imbalances, structural abnormalities in the heart, high blood pressure, thyroid disorders, excessive caffeine or alcohol, certain medications, and stress. Some people are born with electrical pathway abnormalities that predispose them to arrhythmias.

If you experience heart palpitations, a racing heart, dizziness, or fainting episodes, an arrhythmia may be the cause. While many arrhythmias are benign, some require treatment to prevent serious complications including stroke and heart failure. Atrial fibrillation in particular is a major risk factor for stroke because the irregular heartbeat allows blood to pool and form clots in the heart.

Modern treatments for arrhythmias are highly effective. Catheter ablation — a minimally invasive procedure that destroys the tissue causing abnormal electrical signals — can cure many types of arrhythmia. For others, medications or implantable devices provide reliable management.