Arrhythmia (Irregular Heartbeats) Baystate Health offers patients with any kind of irregular heartbeat — including AFib, ventricular fibrillation, bradycardia, and tachycardia —comprehensive and state-of-the-art treatment options, right here in western Massachusetts. What does it mean to have an irregular heartbeat? The electrical system in your heart controls your heart rate (how many times your heart beats in a minute) and your heart rhythm (how regularly your heart beats). If your heartbeat is irregular, you have an arrhythmia. You can have a healthy heart and still have an arrhythmia. Some arrhythmias are harmless. Others may be the sign of heart problems or be caused by a heart attack or heart surgery. Certain arrhythmias are very dangerous and require help immediately. Types of Irregular Heartbeats (Arrhythmias) The most common kinds of arrhythmias include: Tachycardia, which means your heart beats too fast. Bradycardia, also called bradyarrhythmia, means your heart beats too slowly. Ventricular arrhythmias happen in the ventricles (lower heart chambers). Supraventricular arrhythmias happen usually in the atria (upper heart chambers).