An unusual case of permanent junctional reciprocating tachycardia: Successful ablation at the mitral annulus-aorta junction

A unique location of the accessory pathway in a child with permanent junctional reciprocating tachycardia

Permanent junctional reciprocating tachycardia (PJRT) is a rare supra ventricular tachycardia (SVT) due to an accessory pathway (AP), characterized by slow and decremental retrograde conduction, which is predominantly seen in infants and children. Although the typical site of AP in PJRT is a right posteroseptal region around or just within the coronary sinus (CS), atypical sites of AP have been described. We report a rare case of PJRT in a 7-year-old girl with an AP located in the superio-paraseptal (Para-Hsian) region that was successfully ablated through a non-coronary sinus.

Arrhythmias Involving Variants of Accessory Pathways

In some cases, atrioventricular reentrant arrhythmias are sustained by accessory pathways with peculiar electrophysiologic properties related to their specific anatomy. Most of these fibers, which may be responsible for variants of ventricular preexcitation, show decremental conduction properties due to a nodelike aspect or a peculiar tortuous anatomic route across the atrioventricular groove. Moreover, some fibers do not actively sustain any reentrant circuit and can be only involved as bystander in other arrhythmias. Although rare, these accessory pathway variants should be properly diagnosed using noninvasive and invasive methods to guide catheter ablation procedures when needed.

Unusual variants of pre-excitation: From anatomy to ablation: Part III-Clinical presentation, electrophysiologic characteristics, when and how to ablate nodoventricular, nodofascicular, fasciculoventricular pathways, along with considerations of permanent junctional reciprocating tachycardia

The recognition of the presence, location, and properties of unusual accessory pathways for atrioventricular conduction is an exciting, but frequently a difficult, challenge for the clinical cardiac arrhythmologist. In this third part of our series of reviews, we discuss the different steps required to come to the correct diagnosis and management decision in patients with nodofascicular, nodoventricular, and fasciculo-ventricular pathways. We also discuss the concealed accessory atrioventricular pathways with the properties of decremental retrograde conduction that are associated with the so-called permanent form of junctional reciprocating tachycardia. Careful analysis of the 12-lead electrocardiogram during sinus rhythm and tachycardias should always precede the investigation in the catheterization room. When using programmed electrical stimulation of the heart from different intracardiac locations, combined with activation mapping, it should be possible to localize both the proximal and distal ends of the accessory connections. This, in turn, should then permit the determination of their electrophysiologic properties, providing the answer to the question "are they incorporated in a tachycardia circuit?". It is this information that is essential for decision-making with regard to the need for catheter ablation, and if necessary, its appropriate site.

Permanent junctional reciprocating tachycardia in a patient with an atypically located accessory pathway in the left lateral mitral annulus

Permanent junctional reciprocating tachycardia (PJRT) is an uncommon form of atrioventricular reentrant tachycardia due to an accessory pathway characterized by slow and decremental retrograde conduction. The majority of accessory pathways in PJRT are located in the posteroseptal zone. Few cases of atypical location have been described. We report a case of PJRT in a 72-year-old woman in whom the accessory pathway was located in the left lateral region and treated by radiofrequency catheter ablation.

A rare cause of vomiting in a 5-year-old girl

A 5-year-old previously healthy girl presented to the emergency department (ED) with vomiting for 6 days. Her activity level was normal but her parents described progressive exercise intolerance with frequent recreational breaks approximately 2 days prior to presentation. In addition, the child complained of mild abdominal discomfort that began 24 hours prior to her presentation. She had no diarrhea or changes in her diet or oral intake; she had no dysuria or changes in urination. She had no cough, shortness of breath, dizziness, vision changes, falls, or decreased coordination.

Electrophysiologic characteristics of ventricular arrhythmias arising from the aortic mitral continuity-potential role of the conduction system

INTRODUCTION

Catheter ablation of ventricular arrhythmia (VA) at the fibrous aortic mitral continuity (AMC) has been described, yet the nature of the arrhythmogenic substrate remains unknown.

METHODS

Procedural records of 528 consecutive patients undergoing ablation of VA at Mayo Clinic, Rochester, MN, were reviewed. The electrocardiographic and electrophysiologic characteristics of patients with successful ablation at the AMC were analyzed to characterize the underlying arrhythmogenic substrate.

RESULTS

Of the 21 patients (mean age 53.2 ± 13.4 years, 47.6% male) who underwent ablation of VA at the AMC with acute success, prepotentials (PPs) were found at the ablation sites preceding the ventricular electrogram (VEGM) during arrhythmias in 13 (61.9%) patients and during sinus rhythm in 7 (53.8%) patients. VAs with PPs were associated with a significantly higher burden of premature ventricular complexes (PVCs; 26.1 ± 10.9% vs. 14.9 ± 10.1%, P = 0.03), shorter VEGM to QRS intervals (9.0 ± 28.5 milliseconds vs. 33.1 ± 8.8 milliseconds, P = 0.03), lower pace map scores (8.7 ± 1.6 vs. 11.4 ± 0.8, P = 0.001), and a trend toward shorter V-H intervals during VA (32.1 ± 38.6 milliseconds vs. 76.3 ± 11.1 milliseconds, P = 0.06) as compared to those without PP. A strong and positive correlation was found between V-H interval and QRS duration during arrhythmia in those with PPs (B = 2.11, R(2) = 0.97, t = 13.7, P < 0.001) but not in those without PPs.

CONCLUSION

Local EGM characteristics and relative activation time of the His bundle suggest the possibility of conduction tissue as the origin for VA arising from the fibrous AMC. Specific identification and targeting of PPs when ablating VAs at this location may improve procedural success.

A rare case of permanent junctional reciprocating tachycardia ablated on the roof of the left atrium

Left-sided anteroseptal accessory pathways that course through the aortomitral fibrous continuity are some of the rarest types of accessory pathways. At this region the atrium and ventricle are separated by their greatest distance because of the intervening aortic valve. These pathways often have a long circuitous course that may involve the root and cusps of the aortic valve. Prior reports have demonstrated the feasibility of ablating these pathways along the anteroseptal mitral annulus, the left ventricular outflow tract, or in the left or noncoronary cusps of the aortic valve. We describe a case of a concealed decremental anteroseptal accessory pathway that was ablated on the roof of the left atrium remote from the mitral or aortic valve annuli. This report indicates that when an appropriate site for ablation of a left-sided anteroseptal accessory pathway is not found close to a valve annulus, these pathways may be amenable to ablation by targeting their atrial insertion site.