Demonstration of the mechanism of transient entrainment and interruption of ventricular tachycardia with rapid atrial pacing

An unusual case is presented in which ventricular tachycardia at a rate of 141 beats/min was transiently entrained by rapid atrial pacing at rates of 150, 155 and 160 beats/min, and was interrupted by rapid atrial pacing at a rate of 165 beats/min. During each period of transient entrainment, constant ventricular fusion beats were present except for the last entrained beat, and progressive ventricular fusion (different fusion QRS complexes) was demonstrated when comparing QRS complex configurations during transient entrainment at each pacing rate. Interruption of the ventricular tachycardia was associated with localized conduction block to the right ventricular recording site, followed by activation of that site from a different direction and with a shorter conduction time by the subsequent pacing impulse. These data clearly distinguish transient entrainment of a tachycardia from overdrive suppression of a tachycardia, and strongly suggest that reentry was the underlying mechanism of the ventricular tachycardia.

This article has been cited by other articles:

				M. Gulizia, S. Mangiameli, S. Orazi, G. Chiaranda, G. Boriani, G. Piccione, N. DiGiovanni, A. Colletti, C. Puntrello, G. Butera, et al. Randomized comparison between Ramp and Burst+ atrial antitachycardia pacing therapies in patients suffering from sinus node disease and atrial fibrillation and implanted with a DDDRP device Europace, July 1, 2006; 8(7): 465 - 473. [Abstract] [Full Text] [PDF]

				J. B. Morton, P. Sanders, V. Deen, J. K. Vohra, and J. M. Kalman Sensitivity and specificity of concealed entrainment for the identification of a critical isthmus in the atrium: relationship to rate, anatomic location and antidromic penetration J. Am. Coll. Cardiol., March 6, 2002; 39(5): 896 - 906. [Abstract] [Full Text] [PDF]

				J. L. Merino, R. Peinado, I. Fernandez-Lozano, N. Sobrino, and J. A. Sobrino Transient Entrainment of Bundle-Branch Reentry by Atrial and Ventricular Stimulation : Elucidation of the Tachycardia Mechanism Through Analysis of the Surface ECG Circulation, October 26, 1999; 100(17): 1784 - 1790. [Abstract] [Full Text] [PDF]

				J-L Lin, L-P Lai, L-J Lin, Y-Z Tseng, W-P Lien, and S K S Huang Electrophysiological determinant for induction of isthmus dependent counterclockwise and clockwise atrial flutter in humans Heart, January 1, 1999; 81(1): 73 - 81. [Abstract] [Full Text]

				J. S. Strobel, B. H. KenKnight, D. L. Rollins, W. M. Smith, and R. E. Ideker The effects of ventricular fibrillation duration and site of initiation on the defibrillation threshold during early ventricular fibrillation J. Am. Coll. Cardiol., August 1, 1998; 32(2): 521 - 527. [Abstract] [Full Text] [PDF]

				J. M. Davidenko, R. Salomonsz, A. M. Pertsov, W. T. Baxter, and J. Jalife Effects of Pacing on Stationary Reentrant Activity : Theoretical and Experimental Study Circ. Res., December 1, 1995; 77(6): 1166 - 1179. [Abstract] [Full Text]

				B. B. Lerman, K. Stein, E. D. Engelstein, D. S. Battleman, N. Lippman, D. Bei, and D. Catanzaro Mechanism of Repetitive Monomorphic Ventricular Tachycardia Circulation, August 1, 1995; 92(3): 421 - 429. [Abstract] [Full Text]

				A. E. BUXTON Sudden Cardiac Death--1986 Ann Intern Med, May 1, 1986; 104(5): 716 - 718. [Abstract] [PDF]