What term refers to an irregular or abnormal heart rhythm?

The term that refers to an irregular or abnormal heart rhythm is "arrhythmia." Arrhythmia encompasses a wide range of conditions where the heart beats too quickly, too slowly, or with an irregular pattern. It can result in various symptoms, including palpitations, fainting, or even more severe complications like stroke or sudden cardiac arrest.

While the other terms mentioned are related to heart rhythms, they describe more specific conditions rather than the general category of irregular heart rhythms. Tachycardia refers specifically to a condition where the heart rate is faster than normal, while bradycardia indicates a slower than normal heart rate. Atrial fibrillation is a specific type of arrhythmia characterized by rapid and irregular beating of the atria. Understanding the broader category of arrhythmia helps in recognizing and categorizing various heart rhythm disorders.