Re-entrant Atrioventricular Node Tachycardia Clinical Trial
Official title:
Safety and Efficacy Aspects of a Standardized Stepwise Anatomical Approach for Atrio-Ventricular Nodal Re-entrant Tachycardia Ablation
This proposal aims to evaluate safety and efficacy aspects of a new protocol for AVNRT
ablation, using a stepwise anatomical approach.
The investigators hypothesize that the use of a standardized electro-anatomical guided
strategy, using a sequential approach as follows:
1. Right-side postero-septal tricuspid annulus
2. Coronary sinus
3. Left-side postero-septal mitral annulus
For slow pathway AVNRT ablation is safe and efficient, increasing the chance of a successful
ablation in difficult cases, while reducing the need of re-do procedures and the risk for
high-degree atrio-ventricular block.
The investigators aim to define and implement a new standardized protocol for AVNRT ablation
while at the same time assessing the efficacy and safety of coronary sinus and left-side
approaches for slow-pathway ablation.
Atrio-ventricular nodal reentrant tachycardia (AVNRT) is the most common form of
supraventricular tachycardia in adults. The substrate of AVNRT is dual nodal
atrio-ventricular (AV) physiology represented by the presence of slow (SP) and fast pathway
(FP) conduction. Selective radiofrequency (RF) ablation of the slow AV nodal pathway can
cure the arrhythmia with acute success rates varying from 95 to 98% and low recurrence rates
during long-term follow-up.
The compact AV node sends two posterior extensions with node-like tissue distributed towards
the coronary sinus and tricuspid annulus (right posterior extension) and towards the mitral
annulus (left posterior extension). Earlier literature suggested that the right posterior
nodal extension is involved in the tachycardia circuit of most patients with AVNRT (slow
pathway input). The tachycardia circuit may rarely involve the left posterior nodal
extension, in which case a left-sided ablation procedure is needed. The right-sided approach
is sufficient for the majority of cases and represents today the standard protocol for AVNRT
ablation.
Lee et Al., in view of current anatomical and electrophysiological knowledge concerning the
AV node, proposed the following sequential approach for SP ablation:
I. the isthmus between tricuspid annulus and coronary sinus ostium (the usual site of slow
pathway), II. the tricuspid edge of coronary sinus ostium (by moving the ablation catheter
tip slightly in and out of the coronary sinus), III. the septum lower than coronary sinus
ostium, moving higher up on the half of Koch's triangle along the septum, IV. one or two
burns inside the first few centimeters of the coronary sinus, V. left side of the septum
(last).
The investigators hypothesize that the use of a standardized electro-anatomical guided
strategy, using a sequential approach as follows:
1. Right-side postero-septal tricuspid annulus
2. Coronary sinus
3. Left-side postero-septal mitral annulus
for slow pathway AVNRT ablation is safe and efficient, increasing the chance of a successful
ablation in difficult cases, while reducing the need of re-do procedures and the risk for
high-degree atrio-ventricular block.
The protocol will be applied in all patients undergoing slow pathway ablation for typical
AVNRT. Those with unsuccessful right-sided attempt and who undergo coronary sinus and
left-sided ablation attempt will be eligible for registry inclusion.
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Observational Model: Cohort, Time Perspective: Prospective