Palpitations are abnormally rapid beating of the heart. Palpitations are unpleasant sensations of irregular and/or forceful beating of the heart.

In some patients with Palpitations, no heart disease or abnormal heart rhythms can be found. Reasons for their Palpitations are unknown. In others, palpitations result from abnormal heart rhythms called Arrhythmias. Arrhythmias refer to heartbeats that are too slow, too rapid, irregular, or too early. Rapid Arrhythmias (greater than 100 beats per minute) are called Tachycardias. Slow Arrhythmias (slower than 60 beats per minute) are called Bradycardias. Irregular heart rhythms are called Fibrillations, as in atrial fibrillation. When a single heartbeat occurs earlier than normal, it is called a premature contraction. Abnormalities in the atria, the ventricles, the SA node, and the AV node of the heart can lead to Arrhythmias.

List of books: Palpitations