title: Cryoablation of AVNRT when sustained tachycardia cannot be induced.
abstract: BACKGROUND
  Inducibility of sustained tachycardia is preferred prior to cryoablation for atrioventricular nodal reentrant tachycardia (AVNRT).
  
  
  METHODS
  The Pediatric Electrophysiology Database of a single institution was retrospectively reviewed for patients with clinical sustained (≥ 30 seconds of symptoms) AVNRT documented by noninvasive means who underwent cryoablation for AVNRT to determine if intermediate-term success with cryoablation for AVNRT can be achieved without inducibility of sustained AVNRT during electrophysiology study (EPS).
  
  
  RESULTS
  There were no differences between patients with sustained (≥ 30 seconds of tachycardia) AVNRT (N = 67) and patients with nonsustained (ns, ≥ 3 beats and <30 seconds of tachycardia) AVNRT at EPS (N = 16). Acute success was achieved without PR prolongation in all patients. Although duration of follow-up was shorter for the sustained group than the nonsustained group (2.7 ± 1.6 years vs 3.8 ± 1.4 years, P = 0.008), recurrence rate was similar (6% vs 6.3%, P = 0.6). In patients with only nonsustained AVNRT at EPS, supportive findings for procedural effectiveness seen: (1) Dual atrioventricular node physiology (DAVNP) was eliminated in 14/14, (2) the fast pathway effective refractory period (FPERP) decreased after ablation in 10/11, (3) sustained slow pathway conduction was eliminated in 8/8 including both patients without discrete DAVNP prior to ablation, and (4) FPERP increased during lesion formation in 10/10.
  
  
  CONCLUSIONS
  Intermediate-term success can be achieved with cryoablation of ns AVNRT. Attention should be paid to supportive indicators of damage to slow pathway.
authors: Division of Pediatric Cardiology, The Steven and Alexandra Cohen Children's Medical Center of New York, New Hyde Park, New York 11040, USA. PSunthar@NSHS.edu
authors: Patcharapong
authors: P
authors: Suntharos
authors: Andrew D
authors: AD
authors: Blaufox
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018780:Body Surface Potential Mapping / Q000706:statistics & numerical data*; D015897:Comorbidity; D003452:Cryosurgery; D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D016896:Treatment Outcome