Syncope, Tilt Testing, and Cardioversion

Abstract

Syncope is a frequent diagnostic and therapeutic challenge for emergency room physicians, primary care providers, cardiologists and electrophysiologists. Syncope accounts for 3 % of emergency room visits and 6 % of all hospital admissions, with a lifetime incidence of nearly 40 %. Syncope is derived from the Greek word synkopē, which means “to cut short” or “to interrupt”. Syncope is defined by transient loss of consciousness due to global cerebral hypoperfusion. It is characterized by rapid onset, short duration, and spontaneous complete recovery. Understanding the pathophysiological basis for the syncopal episode is the most useful tool for etiology-based treatment and risk assessment. The classification of syncope based on pathophysiology is discussed.

Tilt Table Testing is utilized to demonstrate the hemodynamic response to passive upright challenge. This can be helpful evaluating the underlying cause of unexplained syncope. A positive tilt table test reproduces the patient’s symptoms along with demonstrating an abnormal hemodynamic response to upright challenge.

Perhaps the simplest yet most utilized and useful tool in cardiac electrophysiology is the cardioversion. A synchronized biphasic transient delivery of electrical current is utilized to successfully convert abnormal heart rhythms back to normal sinus rhythm. Techniques to improve safety and success of energy delivery are discussed.