International Journal of Cardiology 188 (2015) 40
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
Empiric slow pathway ablation in suspected but not proven AVNRT: Reply to letter from Dr. Yetkin Mohammed Shurrab, David Newman, Eugene Crystal ⁎ Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
a r t i c l e
i n f o
Article history: Received 4 February 2015 Accepted 17 March 2015 Available online 30 March 2015 Keywords: AVNRT Empiric slow pathway ablation Electrophysiology study
We would like to thank Dr. Yetkin [1] for his interest in our paper entitled “Empiric slow pathway ablation in non-inducible supraventricular tachycardia” [2]. While we agree with Dr. Yetkin that the approach of patients with history suggestive of supraventricular tachycardia (SVT) could be individualized according the patients' needs, we believe that documentation of the clinical SVT is extraordinary important to proceed with electrophysiology study (EPS) and possible empiric slow pathway ablation (ESPA) in cases with non-inducibility of SVT. Given the wide variety of presenting symptoms of patients with SVT, it is hard to make a clear distinguish between different types of SVT including atrial fibrillation (AF) and atrial flutter (AFL). Prior studies showed that symptoms like neck fullness or pulsations could be useful to differentiate atrioventricular nodal reentrant tachycardia (AVNRT) from other types of SVT but neither was useful in distinguishing typical AVNRT from AF or AFL [3,4]. And patients with SVT are often presenting with atypical symptoms as the case presented by Dr. Yetkin. An EPS may result in the induction of nonspecific arrhythmias (AF, AFL etc.) abetted by the use of provocative medications (e.g., isoproterenol). These arrhythmias may not represent index arrhythmia (and therefore may not be clinically meaningful), which makes any decision for ablation more challenging. Further, patients could experience symptom reproducing sinus tachycardia, which would also undermine the specificity of any decision for ESPA. In our cohort of patients with ESPA, the documentation of pre-EPS short RP tachycardia (defined as R–P interval of less than 70 ms during the tachycardia) was a powerful predictor of long-term success. This indeed is important in supporting the decision of ESPA in the presence of associated risks especially the concerning but infrequent risk of ⁎ Corresponding author at: Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Suite D-377, Toronto, ON M4N 3M5, Canada. E-mail address: [email protected] (E. Crystal).
http://dx.doi.org/10.1016/j.ijcard.2015.03.408 0167-5273/© 2015 Elsevier Ireland Ltd. All rights reserved.
complete AV block requiring permanent pacemaker implantation. In the current era of advanced long-term monitoring devices, the ability to capture the clinical arrhythmia becomes feasible in the majority of the patients. Many efforts should be directed to capture the clinical arrhythmia before proceeding with an EPS to ease the decision of appropriate ablation of the targeted clinical arrhythmia substrate. In a survey conducted by our group assessing the practice of ESPA among Canadian electrophysiologists, we found that operators were more likely to perform ESPA in the setting of non-inducible SVT when there was documentation of the clinical arrhythmia (64 vs. 31% (p = 0.017)) [5]. That said; we note Dr. Yetkin's case as it presents a highly symptomatic patient with the absence of documentation, but inducibility of AVNRT during the EPS. In highly selected and symptomatic patients when the documentation of SVT is impossible (i.e., very infrequent episodes), EPS plus ablation might be the only option even in the absence of documentation. Whether ESPA in such a case would be done without induction of AVNRT is arguably more tenuous, but from the survey published is something our colleagues would theoretically consider. Ultimately a study is required to randomize patients who are presenting with symptoms suggestive of SVT but without documentation to proceed with EPS and possible ESPA in the absence of inducibility. This indeed will help operators in making the decision in difficult cases in the setting of lack of arrhythmia documentation and/or noninducibility during EPS. Conflict of interest None. References [1] E. Yetkin, Documented but non-induced supraventricular tachycardia and the vice versa, Int. J. Cardiol. 182C (2015 Jan 3) 438–439. [2] M. Shurrab, T. Szili-Torok, F. Akca, I. Tiong, D. Kagal, D. Newman, I. Lashevsky, O. Onalan, E. Crystal, Empiric slow pathway ablation in non-inducible supraventricular tachycardia, Int. J. Cardiol. 179 (2015) 417–420. [3] G. Laurent, H. Leong-Poi, I. Mangat, V. Korley, A. Pinter, X. Hu, P.P. So, A. Ramadeen, P. Dorian, Influence of ventriculoatrial timing on hemodynamics and symptoms during supraventricular tachycardia, J. Cardiovasc. Electrophysiol. 20 (February 2009) 176–181. [4] R. Sakhuja, L.M. Smith, Z.H. Tseng, N. Badhwar, B.K. Lee, R.J. Lee, M.M. Scheinman, J.E. Olgin, G.M. Marcus, Test characteristics of neck fullness and witnessed neck pulsations in the diagnosis of typical AV nodal reentrant tachycardia, Clin. Cardiol. 32 (8) (2009 August) E13–E18. [5] A. Laish-Farkash, M. Shurrab, S. Singh, I. Tiong, A. Verma, G. Amit, A. Kiss, F. Morriello, D. Birnie, J. Healey, I. Lashevsky, D. Newman, E. Crystal, Approaches to empiric ablation of slow pathway: results from the Canadian EP web survey, J. Interv. Card. Electrophysiol. 35 (2012) 183–187.
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
Empiric slow pathway ablation in suspected but not proven AVNRT: Reply to letter from Dr. Yetkin Mohammed Shurrab, David Newman, Eugene Crystal ⁎ Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
a r t i c l e
i n f o
Article history: Received 4 February 2015 Accepted 17 March 2015 Available online 30 March 2015 Keywords: AVNRT Empiric slow pathway ablation Electrophysiology study
We would like to thank Dr. Yetkin [1] for his interest in our paper entitled “Empiric slow pathway ablation in non-inducible supraventricular tachycardia” [2]. While we agree with Dr. Yetkin that the approach of patients with history suggestive of supraventricular tachycardia (SVT) could be individualized according the patients' needs, we believe that documentation of the clinical SVT is extraordinary important to proceed with electrophysiology study (EPS) and possible empiric slow pathway ablation (ESPA) in cases with non-inducibility of SVT. Given the wide variety of presenting symptoms of patients with SVT, it is hard to make a clear distinguish between different types of SVT including atrial fibrillation (AF) and atrial flutter (AFL). Prior studies showed that symptoms like neck fullness or pulsations could be useful to differentiate atrioventricular nodal reentrant tachycardia (AVNRT) from other types of SVT but neither was useful in distinguishing typical AVNRT from AF or AFL [3,4]. And patients with SVT are often presenting with atypical symptoms as the case presented by Dr. Yetkin. An EPS may result in the induction of nonspecific arrhythmias (AF, AFL etc.) abetted by the use of provocative medications (e.g., isoproterenol). These arrhythmias may not represent index arrhythmia (and therefore may not be clinically meaningful), which makes any decision for ablation more challenging. Further, patients could experience symptom reproducing sinus tachycardia, which would also undermine the specificity of any decision for ESPA. In our cohort of patients with ESPA, the documentation of pre-EPS short RP tachycardia (defined as R–P interval of less than 70 ms during the tachycardia) was a powerful predictor of long-term success. This indeed is important in supporting the decision of ESPA in the presence of associated risks especially the concerning but infrequent risk of ⁎ Corresponding author at: Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Suite D-377, Toronto, ON M4N 3M5, Canada. E-mail address: [email protected] (E. Crystal).
http://dx.doi.org/10.1016/j.ijcard.2015.03.408 0167-5273/© 2015 Elsevier Ireland Ltd. All rights reserved.
complete AV block requiring permanent pacemaker implantation. In the current era of advanced long-term monitoring devices, the ability to capture the clinical arrhythmia becomes feasible in the majority of the patients. Many efforts should be directed to capture the clinical arrhythmia before proceeding with an EPS to ease the decision of appropriate ablation of the targeted clinical arrhythmia substrate. In a survey conducted by our group assessing the practice of ESPA among Canadian electrophysiologists, we found that operators were more likely to perform ESPA in the setting of non-inducible SVT when there was documentation of the clinical arrhythmia (64 vs. 31% (p = 0.017)) [5]. That said; we note Dr. Yetkin's case as it presents a highly symptomatic patient with the absence of documentation, but inducibility of AVNRT during the EPS. In highly selected and symptomatic patients when the documentation of SVT is impossible (i.e., very infrequent episodes), EPS plus ablation might be the only option even in the absence of documentation. Whether ESPA in such a case would be done without induction of AVNRT is arguably more tenuous, but from the survey published is something our colleagues would theoretically consider. Ultimately a study is required to randomize patients who are presenting with symptoms suggestive of SVT but without documentation to proceed with EPS and possible ESPA in the absence of inducibility. This indeed will help operators in making the decision in difficult cases in the setting of lack of arrhythmia documentation and/or noninducibility during EPS. Conflict of interest None. References [1] E. Yetkin, Documented but non-induced supraventricular tachycardia and the vice versa, Int. J. Cardiol. 182C (2015 Jan 3) 438–439. [2] M. Shurrab, T. Szili-Torok, F. Akca, I. Tiong, D. Kagal, D. Newman, I. Lashevsky, O. Onalan, E. Crystal, Empiric slow pathway ablation in non-inducible supraventricular tachycardia, Int. J. Cardiol. 179 (2015) 417–420. [3] G. Laurent, H. Leong-Poi, I. Mangat, V. Korley, A. Pinter, X. Hu, P.P. So, A. Ramadeen, P. Dorian, Influence of ventriculoatrial timing on hemodynamics and symptoms during supraventricular tachycardia, J. Cardiovasc. Electrophysiol. 20 (February 2009) 176–181. [4] R. Sakhuja, L.M. Smith, Z.H. Tseng, N. Badhwar, B.K. Lee, R.J. Lee, M.M. Scheinman, J.E. Olgin, G.M. Marcus, Test characteristics of neck fullness and witnessed neck pulsations in the diagnosis of typical AV nodal reentrant tachycardia, Clin. Cardiol. 32 (8) (2009 August) E13–E18. [5] A. Laish-Farkash, M. Shurrab, S. Singh, I. Tiong, A. Verma, G. Amit, A. Kiss, F. Morriello, D. Birnie, J. Healey, I. Lashevsky, D. Newman, E. Crystal, Approaches to empiric ablation of slow pathway: results from the Canadian EP web survey, J. Interv. Card. Electrophysiol. 35 (2012) 183–187.
