Relationship of late potentials to the ventricular tachycardia circuit defined by entrainment
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Catheter ablation of ventricular tachycardia (VT) depends on the localization of VT circuit. Late potential (LP) recordings in sinus rhythm suggest slow conduction and may help to identify the reentry circuit.
Detailed entrainment mapping was performed to identify VT circuits in 15 patients with structural heart disease. LPs were identified during baseline non-VT rhythm and were defined as electrogram signals occurring beyond the end of surface QRS. The QRS–LP interval was measured from onset of QRS to the latest LP component.
Entrainment was performed in 21 VTs, of which three entrance, 13 isthmus, 17 exit, and one outer loop sites were identified (n = 34). Bipolar electrograms (n = 133 sites) at and in proximity (<1.5 cm distance) to the VT circuit were analyzed. A higher incidence of LP was recorded near isthmus (89%) compared to entrance (57%) or exit (20%), p < 0.05. The QRS–LP intervals were markedly longer at entrance (218 ± 27 ms) and isthmus (194 ± 40 ms) compared to those recorded at exit (131 ± 29 ms), p < 0.05.
Electrograms near the VT circuit isthmus have a higher incidence of LP compared to that of entrance and exit; and the QRS–LP interval is significantly longer near entrance and isthmus compared to exit sites. These findings have important implications in substrate-based ablation strategies targeting LPs.
KeywordsLate potentials Ventricular tachycardia Mapping Catheter ablation
- 1.Josephson, M., Horowitz, L., Farshidi, A., & Kastor, J. (1977). Recurrent sustained ventricular tachycardia: 1. Mechanisms. Circulation, 57, 431–440.Google Scholar
- 2.Josephson, M., Horowitz, L., & Farshidi, A. (1977). Continuous local electrical activity: A mechanism of recurrent ventricular tachycardia. Circulation, 57, 659–665.Google Scholar
- 4.Delacretaz, E., Stevenson, W., Ellison, K., Maisel, W., & Friedman, P. (2000). Mapping and radiofrequency catheter ablation of the three types of sustained monomorphic ventricular tachycardia in nonischemic heart disease. Journal of Cardiovascular Electrophysiology, 11, 11–17.PubMedCrossRefGoogle Scholar
- 8.Cassidy, D., Vassallo, J., Buxton, A., Doherty, J., Marchlinski, F., & Josephson, M. (1984). The value of catheter mapping during sinus rhythm to localize site of origin of ventricular tachycardia. Circulation, 69, 1003–1010.Google Scholar
- 12.Simson, M., Untereker, W., Spielman, S., Horowitz, L., Marcus, N., Falcone, R., et al. (1983). Relation between late potentials on body surface and directly recorded fragmented eletrograms in patients with ventricular tachycardia. American Journal of Cardiology, 51, 105–112.PubMedCrossRefGoogle Scholar
- 15.Soejima, K., Suzuki, M., Maisel, W., Brunckhorst, C., Delacretaz, E., Blier, L., et al. (2001). Catheter ablation in patients with multiple and unstable ventricular tachycardias after myocardial infarction: Short ablation lines guided by reentry circuit isthmuses and sinus rhythm mapping. Circulation, 104, 664–669.PubMedCrossRefGoogle Scholar
- 16.Brunckhorst, C., Stevenson, W., Jackman, W., Kuck, K., Soejima, K., Nakagawa, H., et al. (2002). Ventricular mapping during atrial and ventricular pacing. Relationship of multipotential electrograms to ventricular tachycardia reentry circuits after myocardial infarction. European Heart Journal, 23, 1131–1138.PubMedCrossRefGoogle Scholar
- 23.Arenal, A., del Castillo, S., Gonzalez-Torrecilla, E., Atienza, F., Ortiz, M., Jimenez, J., et al. (2004). Tachycardia-related channel in the scar tissue in patients with sustained monomorphic ventricular tachycardias: Influence of the voltage scar definition. Circulation, 110, 2568–2574.PubMedCrossRefGoogle Scholar
- 24.Schreieck, J., Zrenner, B., Deisenhofer, I., & Schmitt, C. (2005). Rescue ablation of electrical storm in patients with ischemic cardiomyopathy: A potential-guided ablation approach by modifying substrate of intractable, unmappable ventricular tachycardias. Heart Rhythm, 2, 10–14.PubMedCrossRefGoogle Scholar
- 25.Harada, T., Stevenson, W., Kocovic, D., & Friedman, P. (1997). Catheter ablation of ventricular tachycardia after myocardial infarction: Relationship of endocardial sinus rhythm late potentials to the reentry circuit. Journal of the American College of Cardiology, 30, 1015–1023.PubMedCrossRefGoogle Scholar
- 27.Bogun, F., Li, Y., Groenefeld, G., Hohnloser, S., Schuger, C., Oral, H., et al. (2002). Prevalence of a shared isthmus in postinfarction patients with pleiomorphic, hemodynamically tolerated ventricular tachycardias. Journal of Cardiovascular Electrophysiology, 13, 237–241.PubMedCrossRefGoogle Scholar
- 29.Arenal, A., Glez-Torrecilla, E., Ortiz, M., Villacastin, J., Fdez-Portales, J., Sousa, E., et al. (2003). Ablation of electrograms with an isolated, delayed component as treatment of unmappable monomorphic ventricular tachycardias in patients with structural heart disease. Journal of the American College of Cardiology, 41, 81–92.PubMedCrossRefGoogle Scholar