Characterization of the Nodal Slow Pathway in Patients With Nodal Reentrant Tachycardia: Clinical Implications for Guiding Ablation (original) (raw)
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Journal of Cardiovascular Electrophysiology, 1996
Koch's Triangle in AVNRT. Introduction: The dimension of Koch's triaiiftle in patients with AV nodal reentrant tachycardia has not been well described. Understanding the dimension and anatomical distance related to Koch\ triangle might be useful in avoiding accidental AV block during ablation of the slow pathway. The purposes of this study were to define the dimension of Koch^s triangle and its related anatomical distance and correlate these parameters with the successful ahlation sites in patients with AV nodal reentrant tachycardia.
Electroanatomically estimated length of slow pathway in atrioventricular nodal reentrant tachycardia
Heart and Vessels, 2013
The length of the slow pathway (SP-L) in atrioventricular (AV) nodal reentrant tachycardia (NRT) has never been measured clinically. We studied the relationship among (a) SP-L, i.e., the distance between the most proximal His bundle (H) recording and the most posterior site of radiofrequency (RF) delivery associated with a junctional rhythm, (b) the length of Koch's triangle (Koch-L), (c) the conduction time over the slow pathway (SP-T), measured by the AH interval during AVNRT at baseline, and (d) the distance between H and the site of successful ablation (SucABL-L) in 26 women and 20 men (mean age 64.6 ± 11.6 years), using a stepwise approach and an electroanatomic mapping system (EAMS). SP-L (15.0 ± 5.8 mm) was correlated with Koch-L (18.6 ± 5.6 mm; R 2 = 0.1665, P \ 0.005), SP-T (415 ± 100 ms; R 2 = 0.3425, P = 0.036), and SucABL-L (11.6 ± 4.7 mm; R 2 = 0.5243, P \ 0.0001). The site of successful ablation was located within 10 mm of the posterior end of the SP in 38 patients (82.6 %). EAMS-guided RF ablation, using a stepwise approach, revealed individual variations in SP-L related to the size of Koch's triangle and AH interval during AVNRT. Since the site of successful ablation was also correlated with SP-L and was usually located near the posterior end of the SP, ablating anteriorly, away from the posterior end, is not a prerequisite for the success of ablation procedures.
Journal of Cardiovascular Electrophysiology, 1997
Methods and Results: Forty consecutive patients wbo underwent successful ablation of the slow pathway were prospective subjects for tbe study. Isoproterenol was used to enhance conduction and to differentiate interactive mechanisms. Potential electrotonic interactions were assessed by comparing patients with and tbose without residual dual AV node pbysiology after slow patbway ablation. Paired and unpaired f tests were used wben appropriate. P < 0.05 was considered statistically significant. In the entire study population, heart rates were not significantly different before and after slow pathway ablation (RR = 770 ± 114 msec before and 745 ± 99 msec after, P = 0.07). Anterograde fast pathway conduction properties were unchanged after slow pathway ablation (effective refractor> period, 348 ± 84 msec before and 336 ± 86 msec after, P = 0.13; shortest 1:1 conduction, 410 ± 93 msec before and 4(>0 ± 82 msec after, P = 0.39). Retrograde fast patbway cbaracteristics also were similar before and after ablation. Neither anterograde nor retrograde last patbway conduction properties during i.soproterenol infusion were changed by slow pathway ablation. When tbe study population was further divided into patients with (n = 13) or without (n = 27) residual dual AV node pbysiology, no significant change was detected in fast pathway function in either group after slow patbway ablation.
Atrioventricular node properties in patients with accessory pathways
1996
A study during the era of surgical ablation suggested that atrioventricular (AV) nodal conduction is faster in patients with accessory pathways than in controls. In the present study, AV nodal characteristics were studied in 30 patients who underwent radiofrequency ablation of an accessory pathway and compared to 23 control patients. Sinus cycle length, AH and HV intervals, AV block cycle length, ventriculoatrial (VA) block cycle length, AV nodal effective refractory period, and VA effective refractory periods were measured in control and postablation accessory pathway patients before and after autonomic blockade with 0.04 mg/kg of atropine and 0.2 mg/kg of propranolol. The mean sinus cycle length in the control and accessory pathway groups did not differ significantly at baseline (798 +_ 211 and 766 __ 156 msec, respectively) or after autonomic blockade (654 _+ 98 and 649 _+ 108 msec, respectively). The mean AH interval in the accessory pathway group (77 _+ 15 msec) was significantly shorter than in the control group (91 ___ 22 msec; p < 0.05) at baseline; however, there was no difference after autonomic blockade. No other significant differences were observed between the accessory pathway and control groups. These results demonstrate that AV nodal properties of patients with accessory pathways are not significantly different from controls and suggest that previously reported differences may have been due to selection bias. (AM HEART J 1996;131:716-9.) In a study performed during the era of surgical ablation of accessory pathways, it was demonstrated that patients who had undergone surgical division of one or more accessory pathways exhibited atrioventricular (AV) node conduction at significantly shorter paced atrial cycle lengths compared to controls in published data. 1,2 It was concluded that the AV
Pacing and Clinical Electrophysiology, 1994
The present study examined histohgical changes induced by catheter guided radiofrequency current in a patient with AV nodal reentrant tachycardia who underwent cardiac transplantation 1 week after ablation ofthe slow pathway. During the electrophysiology study AV nodal conduction curves were discontinuous and AV nodal reentry was induced. At the conclusion of the procedure there was no evidence of slow pathway function. Histologica! sections from the explanted heart demonstrated a sharply demarcated atrial lesion (5x5x4 mm) extending from the septal portion ofthe tricuspid annuhs to the posterior border of the AV node. The lesion did not encompass the compact AV node. These observations support the hypothesis that the slow pathway is comprised of atrial approaches to the AV node and is distinct from the compact AV node. (PACE, Vol. 17, February 1994) histology, radiofrequency energy, AV node, slow pathway Address for reprints: Bruce
Pacing and Clinical Electrophysiology, 2008
We report a patient with two distinct atrioventricular (AV) nodal slow pathways, participating in two different AV nodal reentrant tachycardias-one eliminated from the right, the other only after ablation on the left side of the posterior septum. The case provides support for the concept of the posterior AV nodal extensions-a biatrial structure in most hearts-representing the anatomic basis of slow pathway conduction.
European Heart Journal, 2001
Aims The objective of this prospective study was to assess risk factors for the development of atrioventricular block following slow pathway modification in patients with atrioventricular nodal reentrant tachycardia and a pre-existing prolonged PR interval. Methods and Results Of 346 consecutive patients with atrioventricular nodal reentrant tachycardia undergoing slow pathway modification, 18 patients (62 7 years; five females) were found to have a prolonged PR interval prior to ablation. Total elimination of the functional slow pathway was assumed if the antegrade effective refractory period following slow pathway modification was longer than the cycle length of atrioventricular nodal reentrant tachycardia. To detect atrioventricular node conduction disturbances, 24-h Holter recordings were performed 1 day prior to slow pathway modification, and 1 day, 1 week, 1, 3 and 6 months after the procedure. Six patients developed late atrioventricular block. The incidence of delayed atrioventricular block following successful slow pathway modification was higher in patients with, compared to patients without, prolonged PR interval at baseline (6/18 vs 0/328, P<0•001). In the former group, the antegrade effective refractory period was longer in patients with, compared to those without, a delayed atrioventricular block (492 150 ms vs 332 101 ms, P<0•05). The incidence of delayed atrioventricular block was higher in patients with total elimination of the slow pathway compared to patients without (5/7 vs 1/11, P<0•01). Conclusions Slow pathway modification in patients with atrioventricular nodal reentrant tachycardia and a prolonged PR interval is highly effective. However, there is a significant risk of development of delayed atrioventricular block, particularly when the procedure results in total elimination of the slow pathway.