Cardiac arrhythmia

Abnormalities in the normal sinus rhythm can prevent the heart from pumping blood effectively and can often be identified on an electrocardiogram. Arrhythmias can cause an abnormal but regular heart rhythm, such as a fast heartbeat (tachycardia, categorized as arising from the supraventricular or from the ventricles) or a slow heartbeat (bradycardia), or they can lead to an irregular heartbeat. Tachycardia can be defined as a heart rate faster than 100 beats per minute, while bradycardia is a heart rate slower than 60 beats per minute.[62] Asystole is the stopping of the heart’s rhythm. The variegated and random heart rhythm is classified as atrial or ventricular fibrillation, depending on whether the electrical activity originates in the atria or in the ventricles.[62] Abnormal conduction can lead to delayed or abnormal contraction of the heart muscle, and this can be the result of a pathological process such as heart block or congenital Wolff-Parkinson-White syndrome. [62]