There are four main types of irregular heartbeats, also known as arrhythmia, including premature or extra beats, supraventricular arrhythmias, ventricular arrhythmias and bradyarrhythmias, according to the National Heart, Lung, and Blood Institute. Premature beats are the most prevalent type of arrhythmia.
Premature beats usually do not cause symptoms, but they could be accompanied by a fluttering in the chest, states the National Heart, Lung, and Blood Institute. This type of arrhythmia typically does not require treatment. Supraventricular arrhythmias are quick heart rates that start in the atria or atrioventricular node. Ventricular arrhythmias occur in the lower chambers of the heart and are very serious conditions. Bradyarrhythmias are diagnosed when the heart rate is slower than normal.