Value of EP Study and Other Cardiac Investigations.

With the advent of implantable loop recorders capable of prolonged electrocardiographic monitoring, and following studies demonstrating the benefit of implantable cardioverter-defibrillator therapy in subgroups of patients with structural heart disease and depressed left ventricular function, the role of invasive cardiac electrophysiologic (EP) studies in patients with unexplained syncope has been substantially reduced. Nonetheless, in select high-risk patients presenting with unexplained syncope, EP studies still play an important role in identifying a diagnosis in these patients and assessing long-term risk of mortality.