Atrioventricular nodal reentrant tachycardia and persistent left superior vena cava: A tough nut to crack. Successful ablation with transseptal approach

High-density electro-anatomical activation mapping to guide slow pathway modification in patients with persistent left superior vena cava

BACKGROUND

Slow pathway (SP) mapping and modification can be challenging in patients with persistent left superior vena cava (PLSVC) due to anatomical variance of Koch's triangle (KT) and coronary sinus (CS) dilatation. There is a lack of studies using detailed 3-dimensional (3D) electro-anatomical mapping (EAM) to investigate conduction characteristics and guide ablation targets in this condition.

OBJECTIVES

To describe a novel technique of slow pathway mapping and ablation in sinus rhythm using 3D EAM in patients with PLSVC after validation in a cohort with normal coronary sinus anatomy.

METHODS

Seven patients with PLSVC and dual AV node physiology who underwent slow pathway modification with the use of 3D EAM were included. Twenty-one normal heart patients with AV nodal re-entrant tachycardias formed the validation group. High-resolution, ultra-high-density local activation timing (LAT) mapping of the right atrial septum and proximal coronary sinus in sinus rhythm was performed.

RESULTS

SP ablation targets were consistently identified by an area in the right atrial septum with the latest activation time and multi-component atrial electrogram (EGM) adjacent to a region with isochronal crowding (deceleration zone). In PLSVC patients, these targets were located at or within 1 cm of the mid anterior CS ostium. Ablation in this area led to successful SP modification reaching standard clinical endpoints with a median of 43 sec of radio frequency energy or 14 mins of cryoablation without complications.

CONCLUSION

High-resolution activation mapping of Koch's triangle in sinus rhythm can facilitate localisation and safe slow pathway ablation in patients with PLSVC.

Imaging evaluation of a persistent left superior vena cava and its importance in electrophysiologic procedures

Accurate characterization of thoracic vascular structures is essential to safe, efficient, and successful cardiac electrophysiologic procedures. Here we describe a case of persistent left superior vena cava incidentally discovered during an elective cryoablation of atrial fibrillation procedure to illustrate possible diagnostic modalities to identify vascular abnormalities.

Cryoablation for atrioventricular nodal re-entrant tachycardia associated with persistent left superior vena cava

Catheter ablation for atrioventricular nodal re-entrant tachycardia (AVNRT) in patients with persistent left superior vena cava (PLSVC) is challenging because of anatomical abnormalities of Koch's triangle associated with the enlarged coronary sinus ostium. We present the Case of successful ablation in a patient with PLSVC using the cryoablation technique. The ablation was successfully performed without damaging the conduction system by virtue of “cryomapping” and “cryoadhesion.” Cryoablation is a safe and efficacious alternative to radiofrequency catheter ablation for the treatment of AVNRT associated with PLSVC.

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Catheter ablation for AVNRT in patients with PLSVC is challenging

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We performed successful ablation in a PLSVC patient with the cryoablation technique

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Ablation was successfully performed without damaging the conduction system

Catheter ablation via the left atrium for atrioventricular nodal reentrant tachycardia: A narrative review

Background

Since 1996, it has been recognized that catheter ablation for atrioventricular nodal reentrant tachycardia (AVNRT) may require an approach through the left atrium.

Objective

The purposes are to present a case report and to provide a comprehensive narrative review on this topic.

Methods

A literature review of all articles that provided detailed information on patients who underwent catheter ablation via the left atrium for AVNRT was performed. The primary search queried PubMed using Medical Subject Headings (MeSH) terms "atrioventricular nodal reentrant tachycardia" and "left." The secondary search was performed by manual review of reference lists and Google Scholar citations of manuscripts retrieved by the primary search. The review was limited to the English language.

Results

The searches yielded 30 articles that described 79 patients. A case report was added. Therefore, the final review consisted of 80 patients. The prevalence of left atrial ablation for patients with AVNRT undergoing catheter ablation at tertiary care centers was approximately 1%. Failed right atrial ablation, with or without coronary sinus ablation, was the most common indication for left atrial ablation. Pooled data from 3 cohort studies estimated the acute success rate for radiofrequency ablation of the slow pathway at the septal or inferoparaseptal segments of the mitral valve annulus after failed right-sided ablation to be 90%. There were no reports of atrioventricular block requiring permanent pacemaker implantation.

Conclusion

Catheter ablation of the slow pathway via the left atrium is an important technique for AVNRT cases that are refractory to conventional ablation.

Ablation of atrioventricular-nodal-reentrant- tachycardia in a patient with left-sided superior vena cava and dilated coronary sinus

Atrioventricular (AV)-nodal-reentrant-tachycardia is a rare association in a patient with persistent left-sided superior vena cava and dilated coronary sinus. There are a few inherent difficulties in ablation in this condition, viz., difficulty in localization of good site for ablation and difficulty in stabilization of the ablation catheter at the designated site, making it difficult to produce transmural lesions and increasing risk of producing AV block. We hereby present a case highlighting the difficulties and possible solutions for them.