Unusual Atrioventricular Reentry Tachycardia in Congenitally Corrected Transposition of Great Arteries: A Novel Site for Catheter Ablation

A short RP tachycardia in congenitally corrected transposition. What is the mechanism?

A 51-year-old female with congenitally corrected transposition of great arteries (CCTGA), situs solitus, dextrocardia, atrial septal defect and persistent left superior vena cava underwent electrophysiology study for recurrent palpitations with documented narrow complex, short RP tachycardia. With a catheter in the region of the anterior mitral annulus, a His signal was recorded and HV interval was 35 msec. Tachycardia was induced with a ventricular extrastimulus. During the tachycardia there was 1:1 ventriculo-atrial conduction and central atrial activation with a VA interval of 20 msec. The recorded His signal could be seen after the QRS. What is the mechanism of the tachycardia?

Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia in Patients With Congenital Heart Disease

Atrioventricular (AV) nodal reentrant tachycardia represents the most common regular supraventricular arrhythmia in humans, and catheter ablation of the so called slow AV nodal pathway has been effectively performed for decades. In patients with congenital heart disease, a combination of different factors makes catheter ablation of AV nodal reentrant tachycardia substrate particularly challenging, including abnormal venous access to intracardiac structures, abnormal intracardiac anatomy, potentially deviant and often unpredictable sites of the specific conduction system, loss of traditional anatomic landmarks, and congenital cardiac surgery that may complicate the access to the AV nodal area. Published experiences have confirmed the efficacy and the relative safety of such procedures when performed by experts, but the risk of complications, in particular AV block, remains non-negligible. A thorough knowledge and understanding of anatomic and electrical specificities according to underlying phenotype are essential in addressing these complex cases. Considering the major consequences associated with AV block in patients with complex congenital heart disease, particularly those without low risk access for transvenous ventricular pacing (eg, single ventricle physiology or Eisenmenger syndrome), the individual risk-benefit ratio should be carefully evaluated. The decision to defer ablation may be the wisest approach in selected patients with either infrequent or hemodynamically tolerated arrhythmias, or when the location of the AV conduction pathways remains uncertain. This narrative review aims to synthetize existing literature on catheter ablation of AV nodal reentrant tachycardia in congenital heart disease, to present main features of common associated pathologies, and to discuss approaches to mapping and safely ablating the slow AV nodal pathway in challenging cases.

Mechanical Support With Impella During Malignant Arrhythmia Ablation: A Case Report on the Growing Trend in the Electrophysiology Laboratory

Congenitally corrected transposition of the great arteries is a rare form of congenital heart disease in which the persistence of the right ventricle as the systemic ventricle leads to heart failure, tricuspid valve insufficiency, and arrhythmia. Supraventricular arrhythmias are especially common in these patients. We discuss the anesthetic management of a 33-year-old patient with congenitally corrected transposition of the great arteries who required a ventricular assist device to maintain cardiac output during ablation of supraventricular tachyarrythmia. A witnessed pulseless cardiac arrest and resuscitation during a previous episode of supraventricular tachycardia prompted the elective insertion of the Impella catheter after induction of anesthesia for the ablation procedure.

Congenitally corrected transposition of great vessels with infundibular pulmonary stenosis with ventricular septal defect, presenting with atypical atrioventricular nodal reentrant tachycardia: a rare association

Congenitally corrected transposition of great vessels (CCTGV) is a rare congenital heart disease (CHD) accounting for <1% of CHDs. CCTGV with infundibular pulmonary stenosis (PS) with ventricular septal defect (VSD) is part of Fallot’s physiology. It is known to be associated with bradyarrhythmias like atrioventricular (AV) blocks, and acquired complete AV block occurs at a rate of 2% per year. Patients can have left-sided accessory pathways, which may cause atrioventricular reentrant tachycardia (AVRT). Tachyarrhythmias like atrioventricular nodal reentrant tachycardia (AVNRT) are very rare in such patients. A 30-year-old woman, a known case of CCTGV with PS with VSD, not corrected surgically and not on any drugs, presented with the syndrome of paroxysmal supraventricular tachycardia without hemodynamic compromise. Electrocardiogram showed atypical AVNRT. She was pharmacologically cardioverted to normal sinus rhythm with adenosine. CTGV with PS with VSD known to be associated with AV blocks, and preexcitation can sometimes present with atypical AVNRT.

Introduction to the Congenital Heart Defects: Anatomy of the Conduction System

The position and course of the conduction system in congenital heart disease are intricately tied to the underlying congenital malformation. Although only subtle differences exist between the anatomy of the conduction axis for simple congenital heart lesions and normal anatomy, almost every patient with congenital heart disease harbors some important anatomic variation. This article summarizes the body of literature by retaining original classical concepts and by attempting to translate the available knowledge into useful points for the congenital heart disease specialist. This discussion spans the entire spectrum of simple to complex congenital heart disease.