Cardiac arrhythmias are conditions that involve irregularities in the heart beat. It can be generally classified based on the speed of the heart rate as tachycardia and bradycardia. Tachycardia is a condition in which the heart beats more than 100 times per minute. There are several types of tachycardia such as atrial fibrillation, atrial flutter, supraventricular tachycardia, ventricular fibrillation, and ventricular tachycardia. Bradycardia involves a heart rate less than 60 beats per minute. It can be categorized into sick sinus syndrome and conduction block. Some common symptoms of cardiac arrhythmia are chest pain, palpitations, anxiety, etc. Clinical management of cardiac arrhythmias includes different types of medications and invasive therapies. Electrical cardioversion is a type of treatment in which an electrical impulse is conveyed through the chest wall. It is used to synchronize the heart and allow the normal rhythm to restart. This book provides significant information of cardiac arrhythmias to help develop a good understanding of their mechanism and clinical management. It is a vital tool for all researching and studying these medical conditions.