 The training required to become an electrophysiologist is lengthy and requires seven to eight years after medical school (in the U.S.), entailing three years of internal medicine residency, three years of clinical cardiology fellowship, and one to two (in most instances) years of clinical cardiac electrophysiology.An electrophysiology study is any of a number of invasive (intracardiac) and non-invasive recording of spontaneous electrical activity, as well as of cardiac responses to programmed electrical stimulation.These studies are performed to assess arrhythmias, elucidate symptoms, evaluate abnormal electrocardiograms, assess risk of developing arrhythmias in the future, and design treatment.