This is a sub speciality in Cardiology which deals with diagnosing and treating rhythm disorders of the heart which are called arrhythmias. Electro physiologists are also involved in implantation of pacemakers and defibrillators.

Electrophysiology study (EP study) is a minimally invasive procedure done under local anaesthesia and is used to investigate the cause, location, and treatment of various rhythm disorders. Once the cause and location is identified, the focus can be ablated by Radiofrequency waves (Radio frequency ablation). Atrial fibrillation (irregular fast heart), atrial flutter, Brady Arrhythmias (slow heart rate), supra ventricular tachycardia, syncope (loss of consciousness), ventricular arrhythmias can be treated.