Differentiate AVNRT from Orthodromic AVRT

Assiut University

Status: Not yet enrolling

Conditions: SVT

Treatments: Diagnostic Test: catheter ablation

Study type: Interventional

Funder types: Other

Identifiers

NCT06671145

AVNRT and orthodromic AVRT

Details and patient eligibility

About

To study new maneuvers to differentiate AVNRT from orthodromic AVRT including VA interval variability at tachycardia induction, SA-VA base and local VA index (difference between local VA interval, measured on the coronary sinus catheter during tachycardia and entrainment, at the site of earliest atrial activity).

Full description

The differentiation of atrioventricular nodal reentrant tachycardia (AVNRT) from atrioventricular reciprocating tachycardia (AVRT) as well as the localization of accessory pathways (APs) is necessary to guide the catheter ablation of supraventricular tachycardia (SVT). However, existing techniques may prove challenging in differentiating atypical forms of AVNRT from AVRT using a septal AP; or localizing AVRT with different septal AP insertion sites.

There are many diagnostic maneuvers during electrophysiological study eg ventriculo atrial interval (VA) during tachycardia, postpacing interval tachycardia cycle length (PPI-TCL) and stimulus atrial ventriculaoatrial interval (SA-VA). It is important to recognize that as with most diagnostic tests, no single observation or maneuver is 100% sensitive or specific. Therefore, it is important to obtain data from multiple observations and maneuvers to verify the diagnosis.

Also, utility of these techniques usually depends on the tachycardia to be sustained, however sometimes tachycardia is rapidly terminating. VA interval at initiation of tachycardia is usually variable and becomes fixed after several beats. This may be explained by differences in retrograde conduction between AVRT and AVNRT which may be better exposed at the time of tachycardia induction, So measuring the number of beats until VA becomes fixed may theoretically help in differentiating AVNRT from AVRT.

Although several reports have demonstrated the usefulness of the SA-VA using right ventricular (RV) apical stimulation (SA-VAapex) to distinguish AVNRT from AVRT, there remains significant overlap in the SA-VA complicating the distinction between these 2 arrhythmias.

Theoretically, stimulation from the RV basal septum (SA-VAbase) would be expected to shorten the SA interval in AVRT because atrioventricular pathways insert in the ventricular base. On the other hand, the SA-VAbase should have the opposite effect on AVNRT because the impulse must first pass from the RV base to the apex to access the right bundle.

Enrollment: 80 estimated patients

Sex: All

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• All patients with documented narrow complex supraventricular tachycardia presented to electrophysiology lab including all age and sex patients (in Assiut university cath. lab) and proved to be AVNRT or orthodromic AVRT.

Exclusion criteria

1. Atrial tachycardia
2. Atrial flutter.
3. Atrial fibrillation.
4. Manifest preexcitation on surface ECG -

Trial design

Primary purpose: Diagnostic

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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80 participants in 2 patient groups

group (1)catheter ablation after diagnosis of Atrioventricular Nodal Reentry Tachycardia

Active Comparator group

Description:

diagnosis Atrioventricular Nodal Reentry Tachycardia before catheter ablation

Treatment:

Diagnostic Test: catheter ablation

group (2) catheter ablation after diagnosis of orthodromic Atrioventricular Reentry Tachycardia

Active Comparator group

Description:

diagnosis of orthodromic Atrioventricular Reentry Tachycardia before catheter ablation

Treatment:

Diagnostic Test: catheter ablation