Long RP interval tachycardia. What is the mechanism?

• Main Authors: Javier Jiménez-Díaz, MD, María-Arantzazu González-Marín, Juan J. González-Ferrer, Felipe Higuera-Sobrino
• Format: Article
• Language: English
• Published: Wiley 2017-06-01
• Series: Journal of Arrhythmia
• Subjects: Orthodromic reciprocating tachycardia; Junctional reciprocating tachycardia; Slowly conducting accessory pathway; Tachycardia-induced cardiomyopathy
• Online Access: http://www.sciencedirect.com/science/article/pii/S1880427616300710

A 41-year-old man with a history of tachycardia refractory to multiple antiarrhythmic drugs was sent to our institution. His 12-lead electrocardiogram demonstrated incessant narrow QRS complex tachycardia with negative P waves in the inferior leads and long RP interval. Occasionally, the tachycardia terminated after a P wave and then was restarted after a sinusal beat. An EP study was performed during tachycardia. Intracardiac electrograms during tachycardia and response to pacing maneuvers are shown. What is the tachycardia mechanism?