ATP test in syncope of unknown origin

ATP test in syncope of unknown origin

ATP test in syncope of unknown origin: Very often the etiology of syncope eludes us even after a full diagnostic work up. ATP test is done to decide whether patients with syncope of unknown origin will benefit from cardiac pacing. The utility of ATP test was evaluated in a single blind (patient blinded) multicenter randomized trial by Daniel Flammang, Timothy R Church, Luc De Roy, Jean-Jacques Blanc, Jean Leroy, Georges H Mairesse, Akli Otmani, Pierre J Graux, Robert Frank and Philippe Purnode, ATP Multicenter Study [1]. Eighty patients ((mean age 75.9 ± 7.7 years) with syncope of unknown origin and no evidence of structural heart disease were enrolled in this study between the years 2000 and 2005. ATP test was done with a twenty milligram bolus injection. Those developing AV (atrioventricular) block or SA (sinoatrial) block lasting more than ten seconds were implanted programmable pacemakers and randomized to either dual chamber pacing at 70 beats per minute (active pacing group) or backup atrial pacing at 30 beats per minute. Syncope was noted in only about one fifth of those randomized to active pacing group while it recurred in two thirds of those randomized to back up pacing. Those who had recurrence in the control group was reprogrammed to active pacing after the syncope and only one had a further recurrence. The authors concluded that active dual chamber pacing reduces the risk of recurrence of syncope of unknown origin in elderly patients by three fourths.

Reference

1. Daniel Flammang, Timothy R Church, Luc De Roy, Jean-Jacques Blanc, Jean Leroy, Georges H Mairesse, Akli Otmani, Pierre J Graux, Robert Frank, Philippe Purnode, ATP Multicenter Study. Treatment of Unexplained Syncope: A Multicenter, Randomized Trial of Cardiac Pacing Guided by Adenosine 5′-triphosphate Testing. Circulation. 2012 Jan 3;125(1):31-6