Cardiac arrhythmias refer to the irregularities in the heartbeat. A person in this condition may experience either tachycardia, where heart rate reaches more than 100 beats per minute, or bradycardia, where heart rate reaches 60 beats per minute. Some common symptoms of cardiac arrhythmias are palpitations, dizziness, chest pain, fatigue, blurry vision and sweating. The diagnosis of cardiac arrhythmias includes electrocardiogram tests, stress test, echocardiogram test, cardiac catheterization, etc. Various treatment options available for arrhythmia include invasive therapies, electrical devices, medications, lifestyle changes and surgery. Catheter ablation and electrical cardioversion are some of the invasive therapies that are utilized for eliminating and treating irregular heart rhythms. Pulmonary vein isolation is a type of ablation, which targets those areas which cause atrial fibrillation. Various devices like implantable cardioverter-defibrillator (ICD) and permanent pacemaker can be used to treat arrhythmias. This book outlines the diagnosis and treatment of cardiac arrhythmias in detail. It will also provide interesting topics for research which interested readers can take up. Students, researchers, experts and all associated with the study and treatment of these diseases will benefit alike from this book.