Endocardial mapping of ventricular tachycardia in the intact human heart. II. Evidence for multiuse reentry in a functional sheet of surviving myocardium

Division of Cardiology, Toronto General Hospital, Ontario, Canada.

OBJECTIVE. The purpose of this study was to obtain improved detection and characterization of reentrant circuits in the infarcted human ventricle. BACKGROUND. The return path of reentrant ventricular arrhythmias usually is not manifested in clinical mapping studies but is thought to be formed by isolated bundles of surviving myocytes whose presence is difficult to detect by standard recording techniques. METHODS. We obtained simultaneous unipolar and high gain bipolar recordings using a left ventricular endocardial balloon array in 10 patients with chronic ischemic heart disease undergoing intraoperative mapping of ventricular tachycardia. RESULTS. Three patients demonstrated seven separate ventricular tachycardias that utilized a return tract that was manifested on up to 20% of all left ventricular electrode sites. The recordings suggested an extensive sheet of surviving myocardial fibers with multiple entry and exit points allowing for different reentrant paths at different times all in the same heart. In one patient, five different ventricular tachycardias could be induced, four of which utilized such a sheet. Two of these tachycardias had the same exit point (site of origin) but two different entry points with a long and short return path resulting in long and short tachycardia cycle lengths. The same sheet sustained another tachycardia with one entry and two exit points resulting in two separate "sites of origin" on the endocardium. Such sheets also were seen to insert into the left bundle system. In one patient portions of the sheet could be detected epicardially. CONCLUSION. The existence of such a structure of surviving myocardium with functional pleomorphism may account for unexplained changes in tachycardia cycle length, epicardial entrainment and spontaneous morphologic changes during ventricular tachycardia.

This article has been cited by other articles:

				K. Nanthakumar, J. Jalife, S. Masse, E. Downar, M. Pop, J. Asta, H. Ross, V. Rao, S. Mironov, E. Sevaptsidis, et al. Optical mapping of Langendorff-perfused human hearts: establishing a model for the study of ventricular fibrillation in humans Am J Physiol Heart Circ Physiol, July 1, 2007; 293(1): H875 - H880. [Abstract] [Full Text] [PDF]

				L. Mickleborough Ventricular reconstruction or aneurysm repair using a modified linear repair technique with septal patch when indicated MMCTS, March 24, 2005; 2005(0324): 588. [Abstract] [Full Text] [PDF]

				L. L. Mickleborough, N. Merchant, J. Ivanov, V. Rao, and S. Carson Left ventricular reconstruction: Early and late results J. Thorac. Cardiovasc. Surg., July 1, 2004; 128(1): 27 - 37. [Abstract] [Full Text] [PDF]

				P. Della Bella, S. Riva, G. Fassini, F. Giraldi, M. Berti, C. Klersy, and N. Trevisi Incidence and significance of pleomorphism in patients with postmyocardial infarction ventricular tachycardia: Acute and long-term outcome of radiofrequency catheter ablation Eur. Heart J., July 1, 2004; 25(13): 1127 - 1138. [Abstract] [Full Text] [PDF]

				V. Y. Reddy, P. Neuzil, M. Taborsky, and J. N. Ruskin Short-term results of substrate mapping and radiofrequency ablation of ischemic ventricular tachycardia using a saline-irrigated catheter J. Am. Coll. Cardiol., June 18, 2003; 41(12): 2228 - 2236. [Abstract] [Full Text] [PDF]

				L. L. Mickleborough, N. Merchant, Y. Provost, S. Carson, and J. Ivanov Ventricular reconstruction for ischemic cardiomyopathy Ann. Thorac. Surg., June 1, 2003; 75(90060): S6 - 12. [Abstract] [Full Text] [PDF]

				K. Soejima, W. G. Stevenson, W. H. Maisel, J. L. Sapp, and L. M. Epstein Electrically Unexcitable Scar Mapping Based on Pacing Threshold for Identification of the Reentry Circuit Isthmus: Feasibility for Guiding Ventricular Tachycardia Ablation Circulation, September 24, 2002; 106(13): 1678 - 1683. [Abstract] [Full Text] [PDF]

				E. J. Ciaccio Dynamic Relationship of Cycle Length to Reentrant Circuit Geometry and to the Slow Conduction Zone During Ventricular Tachycardia Circulation, February 20, 2001; 103(7): 1017 - 1024. [Abstract] [Full Text] [PDF]

				T. Nitta, M. Mitsuno, C. K. Rokkas, R. Lee, R. B. Schuessler, and J. P. Boineau Cryoablation of ventricular tachycardia guided by return cycle mapping after entrainment J. Thorac. Cardiovasc. Surg., February 1, 2001; 121(2): 0249 - 258. [Abstract] [Full Text] [PDF]

				D. Z. Kocovic, T. Harada, P. L. Friedman, and W. G. Stevenson Characteristics of electrograms recorded at reentry circuit sites and bystanders during ventricular tachycardia after myocardial infarction J. Am. Coll. Cardiol., August 1, 1999; 34(2): 381 - 388. [Abstract] [Full Text] [PDF]

				T. Nitta, R. B. Schuessler, M. Mitsuno, C. K. Rokkas, F. Isobe, C. S. Cronin, J. L. Cox, and J. P. Boineau Return Cycle Mapping After Entrainment of Ventricular Tachycardia Circulation, March 31, 1998; 97(12): 1164 - 1175. [Abstract] [Full Text] [PDF]

				C. Costeas, N. S. Peters, B. Waldecker, E. J. Ciaccio, A. L. Wit, and J. Coromilas Mechanisms Causing Sustained Ventricular Tachycardia With Multiple QRS Morphologies : Results of Mapping Studies in the Infarcted Canine Heart Circulation, November 18, 1997; 96(10): 3721 - 3731. [Abstract] [Full Text]

				L. Gepstein, G. Hayam, and S. A. Ben-Haim A Novel Method for Nonfluoroscopic Catheter-Based Electroanatomical Mapping of the Heart : In Vitro and In Vivo Accuracy Results Circulation, March 18, 1997; 95(6): 1611 - 1622. [Abstract] [Full Text]

				F. Bogun, M. Bahu, B. P. Knight, R. Weiss, W. Paladino, M. Harvey, R. Goyal, E. Daoud, K. C. Man, S. A. Strickberger, et al. Comparison of Effective and Ineffective Target Sites That Demonstrate Concealed Entrainment in Patients With Coronary Artery Disease Undergoing Radiofrequency Ablation of Ventricular Tachycardia Circulation, January 7, 1997; 95(1): 183 - 190. [Abstract] [Full Text]

				A. Vinet, R. Cardinal, P. LeFranc, F. Helie, P. Rocque, T. Kus, and P. Page Cycle Length Dynamics and Spatial Stability at the Onset of Postinfarction Monomorphic Ventricular Tachycardias Induced in Patients and Canine Preparations Circulation, May 15, 1996; 93(10): 1845 - 1859. [Abstract] [Full Text]

				D. J. Wilber, D. E. Kopp, D. N. Glascock DO, C. A. Kinder, and J. G. Kall Catheter Ablation of the Mitral Isthmus for Ventricular Tachycardia Associated With Inferior Infarction Circulation, December 15, 1995; 92(12): 3481 - 3489. [Abstract] [Full Text]

				H. Nakagawa, W. S. Yamanashi, J. V. Pitha, M. Arruda, X. Wang, K. Ohtomo, K. J. Beckman, J. H. McClelland, R. Lazzara, and W. M. Jackman Comparison of In Vivo Tissue Temperature Profile and Lesion Geometry for Radiofrequency Ablation With a Saline-Irrigated Electrode Versus Temperature Control in a Canine Thigh Muscle Preparation Circulation, April 15, 1995; 91(8): 2264 - 2273. [Abstract] [Full Text]