Tachycardia is an arrhythmia or an irregular heartbeat, in which the heart beats more 100 times per minute.
The heart is a muscle that contracts in rhythmic sequences. Each heartbeat is stimulated by electrical impulses generated by the heart’s conduction system. A normal heart beats 60 – 100 times per minute. An abnormality in the conduction system may disturb the normal rhythm and cause it to beat irregularly or erratically.
During tachycardia, the upper or lower chambers of the heart beat significantly faster, and sometimes the disturbance may occur in both chambers simultaneously. Atrial flutter, atrial fibrillation, ventricular tachycardia, supraventricular tachycardia and ventricular fibrillation are common types of tachycardia.