Transcatheter Interventions in Adult Congenital Heart Disease.

Congenital heart disease (CHD) is the most common congenital birth defect with an incidence of 1 in 100. Current survival to adulthood is expected in 9 out of 10 children with severe CHD as the diagnostic, interventional, and surgical success improves. The adult CHD (ACHD) population is increasingly diverse, reflecting the broad spectrum of CHD and evolution of surgical techniques to improve survival. Similarly, transcatheter interventions have seen exponential growth and creativity to reduce the need for repeat sternotomies. This article focuses on newer data and evolving techniques for transcatheter interventions specific to certain ACHD populations.

Multicenter Outcomes of Catheter Ablation for Atrioventricular Reciprocating Tachycardia Mediated by Twin Atrioventricular Nodes.

OBJECTIVES: This study sought to describe the electrophysiologic properties and catheter ablation outcomes for atrioventricular reciprocating tacchycardia via twin atrioventricular nodes (T-AVRT). BACKGROUND: Although catheter ablation for T-AVRT is an established entity, there are few data on the electrophysiological properties and outcomes of this procedure. METHODS: An international, multicenter study was conducted to collect retrospective procedural and outcomes data for catheter ablation of T-AVRT. RESULTS: Fifty-nine patients with T-AVRT were identified (median age at procedure, 8 years [interquartile range: 4.4-17.0 years]; 49% male). Of these, 55 (93%) were diagnosed with heterotaxy syndrome (right atrial isomerism in 39, left atrial isomerism in 8, and indeterminate in 8). Twenty-three (39%) had undergone Fontan operation (12 extracardiac, 11 lateral tunnel). After the Fontan operation, atrial access was conduit or baffle puncture in 15 (65%), fenestration in 5 (22%), and retrograde in 3 (13%). Acute success was achieved in 43 (91%) of 47 attempts (targeting an anterior node in 23 and posterior node in 24). There was no high-grade AV block or change in QRS duration. Over a median of 3.8 years, there were 3 recurrences. Of 7 patients with failed index procedure or recurrent T-AVRT, 6 (86%) were associated with anatomical hurdles such as prior Fontan or catheter course through an interrupted inferior vena cava-to-azygous vein continuation (P = 0.11). CONCLUSIONS: T-AVRT can be targeted successfully with low risk for recurrence. Complications were rare in this population. Anatomical challenges were common among patients with reduced short and long-term efficacy, representing opportunities for improvement in procedural timing and planning.

Successful radiofrequency perforation and balloon decompression of cor triatriatum sinister using novel technique, a case series.

Cor triatriatum sinister (CTS) is a rare congenital cardiac anomaly representing <0.1% of all congenital cardiac malformations. It is characterized by the presence of a left atrial (LA) membrane that leads to left ventricular inflow obstruction. Uncorrected, obstructed CTS may have significant sequelae such as pulmonary hypertension or arrhythmias. Transcatheter balloon decompression has been described as a successful alternative to surgical resection of the obstructing membrane. Our review of the literature revealed no reported cases utilizing radiofrequency (RF) energy to perforate the CTS membrane prior to balloon decompression. This manuscript describes two patients with CTS who were treated successfully with a transcatheter technique using RF energy to perforate the obstructing membrane prior to balloon angioplasty and decompression of the LA.

Clinical and electrophysiological properties of atrial tachycardia after pediatric heart transplantation.

BACKGROUND: Pediatric heart transplant recipients are at an elevated risk for development of atrial tachycardia (AT); however, the underlying mechanisms and long-term outcomes are unclear. OBJECTIVE: We hypothesized that occurrence of AT in pediatric heart transplant recipients would be associated with a higher frequency of adverse events during follow-up. METHODS: A single-center retrospective review of all pediatric heart transplant recipients with suspected AT between 1997 and 2017 was performed. Unaffected controls were matched with cases for age and transplant era. Clinical characteristics and long-term outcomes were compared between groups. RESULTS: Of 294 heart transplant recipients, 13 with AT at electrophysiology study (4.4%) were identified and compared with 29 controls. The most common mechanism was focal (11), followed by atrial flutter (two), and electrical reconnection of a surgical atrial anastomosis (two). Focal AT was only observed in the right atrium or atrial septum, and was frequently found on or near the crista terminalis. Relative to controls, cases exhibited more frequent clinical evidence of rejection (9/13 vs 10/29, P  =  0.037). For patients with AT, there was a higher rate of death/retransplant among cases (log-rank P  =  0.022), which remained significant in multivariate analysis. CONCLUSION: In this cohort, the most common form of AT after pediatric heart transplantation was focal, with predilection for sites near the crista terminalis. Transplant patients with AT experienced a higher rate of clinical rejection and the composite end-point of retransplantation or death relative to unaffected controls.