Presented in abstract form at 29 and 30th Annual Scientific Sessions of Heart Rhythm Society (2008 and 2009).
Prospective Observations in the Clinical and Electrophysiological Characteristics of Intra-Isthmus Reentry
Article first published online: 28 APR 2010
© 2010 Wiley Periodicals, Inc.
Journal of Cardiovascular Electrophysiology
Volume 21, Issue 10, pages 1099–1106, October 2010
How to Cite
YANG, Y., VARMA, N., BADHWAR, N., TANEL, R. E., SUNDARA, S., LEE, R. J., LEE, B. K., TSENG, Z. H., MARCUS, G. M., KIM, A. M., OLGIN, J. E. and SCHEINMAN, M. M. (2010), Prospective Observations in the Clinical and Electrophysiological Characteristics of Intra-Isthmus Reentry. Journal of Cardiovascular Electrophysiology, 21: 1099–1106. doi: 10.1111/j.1540-8167.2010.01778.x
- Issue published online: 28 APR 2010
- Article first published online: 28 APR 2010
- Manuscript received: 18 December 2009; Revised manuscript received: 11 March 2010; Accepted for publication: 12 March 2010.
- atrial flutter;
- catheter ablation;
- cavotricuspid isthmus;
- entrainment mapping;
- electroanatomic mapping
ECG and EGM of IIR. Introduction: Intra-isthmus reentry (IIR) is a circuit within the cavotricuspid isthmus (CTI). The purpose of this study is to prospectively define the electrogram and surface ECG characteristics of IIR, and its clinical implications.
Methods and Results: Fourteen patients underwent electrophysiological studies and were found to have IIR. Detailed electrogram mapping of the CTI was available in all, electroanatomic mapping (EAM) in 8 of 14 (57%) patients. In all, entrainment mapping during tachycardia proved reentry, and showed that the anteroinferior CTI was out of the circuit and the septal CTI was in the circuit in 12 of 14 patients, whereas in 2, the circuit was confined within the mid and/or anteroinferior CTI. Fractionated potentials (FPs) spanning 34–71% of the tachycardia cycle length were recorded within the CTI in all, and double potentials were inscribed in 10 of 14 (71%). Analysis of the tricuspid annulus electrograms showed spontaneous shifts from a counterclockwise (CCW) to clockwise or fusion patterns. Surface ECGs showed either typical CCW pattern (12 patients) or atypical patterns (3 patients). The EAMs showed a focal pattern in 3, a CCW pattern in 5. The successful ablation site always occurred at the area with maximal FP duration. Over the same period, 33 of 384 (9%) patients who underwent ablation for CTI-dependent flutter had prior successful CTI ablation, 7 of 33 (21%) were found to have IIR during the redo procedure.
Conclusions: (1) Electrogram and ECG patterns of IIR frequently show atypical flutter. (2) IIR was successfully ablated in an area of the CTI associated with maximal duration of FPs. (3) IIR is a significant cause of “recurrent flutter” in patients with prior CTI ablation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1099-1106)