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BACKGROUND Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common type of supraventricular tachycardia (SVT). Similar to other cardiac tests and interventions, gender bias may influence clinical decision making in providing appropriate care for AVNRT patients. We assessed for gender differences in the diagnosis and management of AVNRT patients who underwent catheter ablation. METHODS Patients who underwent catheter ablation for AVNRT were included. We explored the gender difference on various clinical parameters such as the time from SVT symptoms, SVT diagnosis, and first electrophysiology consult to time of catheter ablation. RESULTS Among 140 patients screened, 116 patients met the inclusion criteria, including 67.2% women. Median time from symptoms onset to SVT diagnosis was 18.5 months (interquartile range [IQR] 4.0-58.5) in women versus 4.0 months (0.75-34.7) in men, P = .005. Once SVT was diagnosed, women took a median of 12.5 months (IQR 3.0-57.0) to proceed with ablation versus 3.0 months (1.0-7.0) for men, P ≤ .001. It took a longer time from the first electrophysiology consultation to ablation: 54.5 days (20.75-144.75) for women versus 20.5 days (6.0-46.25) for men, P = .008. Overall, it took 60.0 months (IQR 12.8-132.0) for women to have an ablation from initial symptoms onset versus 15 months (IQR 4.6-48.0) for men, P = .001. Prior to ablation, women had 3.78 ± 3.79 (mean ± SD) emergency department visits for SVT versus men 1.52 ± 1.72 and women tried 1.28 ± 0.82 medications versus men 0.76 ± 0.68, P

Radiofrequency (RF) ablation of the slow pathway (SP) in atrioventricular nodal reentry tachycardia (AVNRT) is occasionally complicated with atrioventricular block (AVB) often predicted by junctional beats (JB) with loss of ventriculo-atrial (VA) conduction.We analyzed retrospectively 153 patients undergoing ablation of SP for typical AVNRT. Patients were divided into two age groups: 127 ≤ 70 years and 26 70 years. We analyzed the interval between the atrial electrogram in the His-bundle position and the distal ablation catheter [A(H)-A(RFd)] and between the distal ablation catheter and the proximal coronary sinus catheter [A(RFd)-A(CS)] before RF applications with and without JB. We evaluated if these intervals can be used as predictors of JB incidence and also of JB with loss of VA conduction. We also assessed if age influences the risk of loss of VA conduction.The A(H)-A(RFd) and A(RFd)-A(CS) intervals were significantly shorter in RF applications causing JB than those without JB (33 ± 11 ms vs 39 ± 9 ms, P 0.001, 14 ± 9 ms vs 20 ± 7 ms, P 0.001, respectively). The A(H)-A(RFd) and A(RFd)-A(CS) intervals were also significantly shorter in RFs causing JB with VA block than those with VA conduction (29 ± 11 ms vs 35 ± 11 ms, P 0.001, 8 ± 8 ms vs 17 ± 8 ms, P 0.001, respectively). Patients 70 years had shorter intervals (36 ± 11 ms vs 29 ± 8 ms, P = 0.012, 17 ± 8 ms vs 13 ± 7 ms, P = 0.027, respectively), while VA block was more common in this age group.The A(H)-A(RFd) and A(RFd)-A(CS) intervals can be used as markers for predicting JB occurrence as well as impending AVB. JB with loss of VA conduction occur more often in older patients possibly due to a higher position of SP.

Background Transcatheter cryoablation is a well-established technique for the treatment of atrioventricular nodal reentry tachycardia (AVNRT) in children. Nevertheless, atrioventricular nodal slow-pathway conduction may recur after an acutely successful procedure. The aim of this study was to evaluate the long-term outcome of acutely successful AVNRT cryoablations in pediatric patients in case of focal cryolesion and in case of need for High-Density Linear Lesion (HDLL) cryoablation due to focal failure. Methods Sixty-nine consecutive pediatric patients (30 males, mean age 12.4 ± 3.2 years; range: 5.4-18.0 years) underwent 3D-guided cryoablation for AVNRT at our institution from July 2013 to November 2014. When a focal cryoablation was acutely unsuccessful, a 3D-guided HDLL was created delivering multiple overlapping cryolesions/cryoenergy applications from the ventricular side of the tricuspid annulus to the atrial side, including the site of focal cryoablation if transiently successful. Results No permanent cryoablation-related complications occurred. Acute success rate was 98.5% (68 out of 69): in 55.9% (38 out of 68) with focal-lesion and in 44.1% (30 out of 68) with HDLL. Mean follow-up was 25.3 months and AVNRT recurrence rate was 13.2% (nine out of 68): 5.2% (two out of 38) with focal lesion and 23.3% (seven out of 30) with HDLL (P = 0.036). Conclusions In cryoablation of AVNRT in children, the need for a more aggressive protocol (HDLL), due to the failure of focal ablation, is strictly related to higher recurrence rates. Indeed, AVNRT recurrences after cryoablation in children seem to be due to a larger and deeper substrate rather than due to the type of energy used.

Background There are limited adult data suggesting the tachycardia cycle length (TCL) of atrioventricular reentry tachycardia (AVRT) is shorter than atrioventricular nodal reentry tachycardia (AVNRT), though little data exist in children. We sought to determine if there is a difference in TCL between AVRT and AVNRT in children. Methods A single-center retrospective review of children with supraventricular tachycardia (SVT) from 2000 to 2015 was performed. Inclusion criteria: Age ≤ 18 years, invasive electrophysiology study (EPS) confirming AVRT or AVNRT. Exclusion criteria: Atypical AVNRT, congenital heart disease, antiarrhythmic medication use at time of EPS. Data were compared between patients with AVRT and AVNRT via t-test, χ2 test, and linear regression. Results A total of 835 patients were included (12 ± 4 years, 52 ± 31 kg, TCL 321 ± 55 ms), 539 (65%) with AVRT (270 Wolff-Parkinson-White, 269 concealed pathways) and 296 (35%) with AVNRT. Patients with AVRT were younger (11.7 ± 4.1 years vs 13.0 ± 3.6 years, P < 0.001) and smaller (49 ± 22 kg vs 57 ± 43 kg, P < 0.001). In the baseline state, the TCL was shorter in AVRT than AVRNT (329 ± 51 ms vs 340 ± 60 ms, P = 0.04). In patients requiring isoproterenol to induce SVT, there was no difference in TCL (290 ± 49 ms vs 297 ± 49 ms, P = 0.26). When controlling for age, there was no difference in TCL between AVRT and AVNRT at baseline or on isoproterenol. The regression equation for TCL in the baseline state was TCL = 290 + 4 (age), indicating the TCL will increase by 4 ms above a baseline of 290 ms for each year of life. Conclusions When controlling for age, there is no difference in the TCL between AVRT and AVNRT in children. Age, not tachycardia mechanism, is the most significant factor in predicting TCL.

A 53-year-old man with previous aortic valve surgery presented with paroxysmal narrow complex tachycardia, induced by exercise. His PR interval was greater than 400 ms when in sinus rhythm and atrioventricular nodal reentry tachycardia (AVNRT) was diagnosed with invasive electrophysiological studies. Single echoes were repeatedly inducible with single-paced extrastimuli. Cryotherapy was then used to ablate the fast pathway using single echoes to monitor anterograde slow pathway and retrograde fast pathway function during ablation. PACE 2012; 35:e47–e51)

Infants and small children with atrioventricular (AV) nodal disease frequently require pacing in order to maintain an adequate heart rate. The maintenance of AV synchrony is physiologically optimal in this setting. Unfortunately, small size and congenital anomalies often preclude the placement of standard transvenous dual chamber pacing systems. We report the case of a small child with a pre-existing dual chamber epicardial pacing system and subsequent ventricular lead dysfunction who underwent implantation of a new single chamber transvenous system which was programmed in VVT (triggered) mode in order to maintain AV synchrony.

This article describes the additional use of incremental atrial burst pacing (A1A1) and double atrial extrastimulation with a predefined fast pathway conducted A2 (A1A2A3), rather than single atrial extrastimulation (A1A2) only, to characterize typical atrioventricular nodal reentrant tachycardia (AVNRT). The authors noted an additional 32% of patients had multiple anterograde AV nodal physiology demonstrated when A1A1 or A1A2A3 protocols were deployed compared to more conventional A1A2 protocols. The A2H2max (449 +/- 147 vs 339 +/- 94 ms) and A3H3max (481 +/- 120 vs 389 +/- 85 ms) were higher in 31 patients where multiple jumps in the AV nodal conduction curve were obtained (group 1) compared to 192 patients where only single jump was obtained (group 2) (both P0.01). Postablation, the degree of reduction of A2H2max (49%) and A3H3max (50%) in group 1 was greater than in group 2 (38% and 42%, respectively, P0.05). In seven of group 1 patients in whom A1A2A3 stimulation was required to reveal multiple jumps, the A2H2max remained unchanged after ablation (237 +/- 89 vs 214 +/- 59, P0.05). A3H3max was the only parameter that shortened significantly after ablation. Generally, successful ablation resulted in loss of multiple discontinuities in A1A1/A1H1 or A2A3/A3H3 curves. In conclusion, a combination of A1A2, A1A1, and A1A2A3 are required to fully elucidate AVNRT. Significant shortening of AHmax or loss of multiple jumps after ablation indicates successful elimination of AVNRT in these patients.

of Atrioventricular Nodal Reentry Tachycardia? Introduction: Current AHA/ACC guidelines state that junctional rhythm (JR) is an acceptable endpoint in patients undergoing radiofrequency ablation (RFA)for narrow complex tachycardia in the presence of dual AV nodal physiology, but in the absence of inducible AVNRT. Only limited data are available on the utility of JR as a marker of successful slow pathway ablation. We sought to further characterize the sensitivity, specificity, and predictive value of JR in AVNRT ablation. Methods: A retrospective analysis was performed of 387 consecutive patients with documented narrow complex tachycardia referred for ablation, with dual AV nodal physiology and inducible AVNRT at electrophysiological study. RFA of slow pathway was performed, with the presence or absence of JR recorded for each application and inducibility tested using atrial stimulation protocol and isoproterenol. Results: Successful ablation was achieved in 385 of 387 patients using a total of 1,861 applications of radiofrequency energy. JR occurred in 692 applications, giving a sensitivity and specificity of JR as an indicator of successful ablation of 99.5% and 79.1% and a positive predictive value of 55.5%. Conclusions: This study confirms That successful ablation of slow pathway seldom occurs in the absence of JR. Although JR almost invariably occurs with successful ablation, its lack of specificity and low positive predictive value questions the use of it as an endpoint in AVNRT ablations, and the guidelines should reflect this.

Atrioventricular nodal reentry tachycardia (AVNRT) is an uncommon mechanism of supraventricular tachycardia in neonates in whom orthodromic reciprocating tachycardia (ORT) predominates. We report three patients with structurally normal hearts who presented with neonatal ORT, documented by transesophageal electrophysiology studies at 2 to 3 weeks of age. At follow-up study at 8-12 months of age, no infant had inducible ORT, suggesting spontaneous regression of congenital accessory pathways; however, each had inducible tachycardia consistent with the typical form of AVNRT. The clinical significance of this finding is unknown and warrants further study.