Slow pathway modification for atrioventricular node re-entrant tachycardia: fast junctional tachycardia predicts adverse prognosis

Abstract

Objective-To examine the cycle length of the junctional tachycardia often seen during successful slow pathway ablation for atrioventricular (AV) node re-entrant tachycardia, to determine whether shorter cycle lengths predict imminent atrioventricular block. Design-Retrospective analysis of consecutive patients undergoing slow pathway modification. Intracardiac recordings were analysed after digital storage to determine the development of junctional tachycardia, its duration and maximum, minimum, and mean cycle length, occurrence of heart block, persistent slow pathway conduction, or later confirmed recurrence of AV node re-entrant tachycardia. Setting-Regional cardiac centre. Patients-136 consecutive patients undergoing electrophysiological study found to have typical "slow-fast" AV node re-entrant tachycardia and subject to 137 slow pathway modification procedures. Results-During successful temperature feedback controlled radiofrequency energy application, junctional tachycardia developed in 133 of 137 procedures. During ablation, 10 patients had evidence of AV block (first degree in seven patients and third degree in three), and 17 others had retrograde junctional atrial (JA) block. In these 27 patients, the junctional tachycardia was rapid, with a minimum (SD) cycle length 291 (47) ms. Conduction recovered quickly in all but two patients, one of whom required permanent pacing. Junctional tachycardia with normal AV and JA conduction in the other 111 patients was of a significantly slower minimum cycle length (537 (123) ms; p < 0.0001). Conclusions-Fast junctional tachycardia with cycle lengths under 350 ms seen during slow pathway modification is a predictor of conduction block, suggesting proximity to the compact node. Radiofrequency energy application should be terminated immediately to prevent development of AV block. An "auto cut oV" facility for cycle lengths shorter than 350 ms could be built into radiofrequency ablation systems to increase safety. (Heart 2001;85:44-47)

First year experience of a new established electrophysiology laboratory

“…As a classic knowledge, acute procedural success is over 95% and recurrence rate is between 2-5% in patients who were diagnosed as AVNRT and underwent slow pathway ablation. [4][5][6][7][8][9][10][11] In our laboratory, excluding two patients who were left for cryoablation at a second session, acute success rate for slow pathway ablation was 100%. In addition, recurrence rate was also comparable with classic rate 2%.…”

Transvenous radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia and its pitfalls: A rationale for cryoablation?

“…Junctional tachycardia is frequently observed during RF ablation, probably due to thermal injury of the compact AV node and/or the perinodal tissue forming the input of fast and slow pathway into the AV node [4,21]. A relatively fast rate of this junctional tachycardia with loss of VA conduction is associated with an increased risk of inadvertent AV block with a positive predictive value of 19% [21].…”

“…If transient AV block occurs during or immediately after the application, and the block still persists at the end of the procedure, it is accompanied by a high incidence of permanent AV block requiring a definitive pacemaker implantation [7,[21][22][23]. Junctional tachycardia is frequently observed during RF ablation, probably due to thermal injury of the compact AV node and/or the perinodal tissue forming the input of fast and slow pathway into the AV node [4,21].…”

Prąd uszkodzenia pęczka Hisa i czynny rytm węzłowy — rozważania kliniczne i techniczne

“…In some procedural circumstances active rhythm precedes permanent harm to some particular elements of cardiac tissue. As an example, during radiofrequency ablation of slow pathway of atrioventricular node a rapid, active nodal rhythm often precedes impairment of compact AV node, a hub that receives stimuli from both fast and slow pathway -resulting in complete AV block [6]. Similarly the accelerated ventricular rhythm with the morphology of the native QRS complex is usually a good predictor of radiofrequency ventricular tachycardia ablation procedure success [7].…”