Successful Ablation of Atypical Atrioventricular Nodal Reentrant Tachycardia From a Noncoronary Sinus of Valsalva

Abstract

SummaryAn 81-year-old man with long RP narrow QRS tachycardia underwent catheter ablation. Ventricular pacing reset the atrial cycle over a retrograde slow pathway, followed by termination of the tachycardia without atrial capture, confi rming the diagnosis of fast-slow atrioventricular nodal reentrant tachycardia (AVNRT). The earliest atrial activation during tachycardia was found in the noncoronary sinus of Valsalva, where the fi rst delivery of radiofrequency energy terminated and eliminated the inducibility of the tachycardia, by retrograde conduction block over the slow pathway. This is the fi rst report of a fast-slow AVNRT, with successful ablation of the slow pathway from a noncoronary sinus of Valsalva. (Int Heart J 2014; 55: 84-86) Key words: Supraventricular tachycardia, Atrioventricular nodal tachycardia, Slow pathway ablation, Noncoronary cusp S low pathway ablation is a curative treatment for atrioventricular (AV) nodal reentrant tachycardia (NRT), and is usually performed with lesions created in the inferior or mid segment of the triangle of Koch.1-3) We describe a rare, atypical AVNRT successfully treated by ablation of a slow pathway from a noncoronary aortic cusp. Case ReportAn 81-year-old man who had a history of multiple episodes of paroxysmal supraventricular tachycardia underwent electrophysiologic studies and a catheter ablation procedure. A 12-lead electrocardiogram during tachycardia showed a long RP tachycardia with biphasic P waves in leads II, III, and aVF. Atrial extrastimulation elicited no dual anterograde AV nodal conduction. Decremental ventriculoatrial conduction and maximum 1:1 conduction at a rate of 110 ppm were observed, with the earliest atrial activation site in the bundle of His region, consistent with retrograde AV nodal conduction (Figure 1). A narrow QRS tachycardia documented previously was reproducibly induced by atrial extrastimulation at a coupling interval of 400 ms to 290 ms and ventricular overdrive pacing (Figure 1). During tachycardia with stable 1:1 AV conduction, the earliest atrial activation was recorded at the bundle of His, as was observed during ventricular overdrive pacing. Retrograde VA conduction could not be evaluated by ventricular extrastimulus due to incessant tachycardia easily induced by ventricular basic stimulation. Wenckebach periodicity with a similar atrial activation sequence was also frequently observed during ongoing tachycardia, excluding the diagnosis of AV reentrant tachycardia. A 4-mg bolus injection of adenosine triphosphate (ATP) reproducibly terminated the tachycardia after a last ventricular event, following incremental prolongation of the atrial cycle length. Ventricular extrastimuli delivered during the tachycardia did not reset the atrial cycle, though ventricular overdrive pacing at a cycle length slightly shorter than that of the tachycardia reset the atrial cycles and terminated the tachycardia (Figure 2). Presuming the presence of dual AV nodal conduction, the electrophysiological observations shown in Figure 2 are exp...

Atypical Fast-Slow Atrioventricular Nodal Reentrant Tachycardia Incorporating a “Superior” Slow Pathway

“…I, II, V 1 , and V 6 are surface ECG; HBE1-2 and 9-10 are distal to proximal HB region; and CS9-10 to 1-2 are proximal to distal coronary sinus (CS) recording. Reprinted from Kaneko et al 4 with permission of the publisher. Copyright © 2014, the International Heart Journal Association.…”

Multiple Shifts of the Earliest Retrograde Atrial Activation Site Along the Tricuspid Annulus During the Fast-Slow Form of Atrioventricular Nodal Reentrant Tachycardia by Radiofrequency Modification

“…2) Recent studies on a series of patients with anterior subtypes were subsequently confirmed to be the superior type of fast-slow AVNRT incorporating a superior SP located near the His bundle. [3][4][5] Furthermore, atypical AVNRT with eccentric retrograde left-sided activation was identified following mapping over the triangle of Koch. 6,7) In addition, several reports indicate multiple fast-slow forms of AVNRT may be associated with anatomically different SPs.…”

“…However, ablation in the region was sometimes ineffective; hence, other approaches were considered due to SP's spatial heterogeneity. [2][3][4][5][6][7][8][9] Several previous reports demonstrated the potential existence of anatomically different multiple SPs, as well as successful ablation sites, such as para-septal regions around the triangle of Koch or the left atrial mitral annulus along the coronary sinus. 8,9) However, retrograde SP bound by the tricuspid annulus has not yet been described adequately.…”

Atypical Fast-Slow Atrioventricular Nodal Reentrant Tachycardia Using a Slow Pathway Extending to the Superoanterior Right Atrium

“…2,5) Therefore, AV block during the tachycardia and VA block during the ventricular pacing of the tachycardia could coexist according to LCP conductivities. 7) Retrograde conduction via the FP during the ventricular pacing of the tachycardia also seemed to be masked according to LCP conductivities. Even if the retrograde wavefront passed via the LCP and penetrated into the FP, it might collide with the antegrade wavefront within the FP.…”