Long-term results of atrial maze surgery in patients with congenital heart disease.

AIMS: Recurrent atrial tachycardia is common after repair of many types of congenital heart disease, and surgical ablation with a maze procedure represents a potential treatment strategy. The objective of this study is to report a single-centre 19 years' experience with maze surgery in congenital heart patients. METHODS AND RESULTS: Patients undergoing maze procedure concomitantly with cardiac surgical procedures were retrospectively analysed. The maze procedure was classified as therapeutic if the patient demonstrated preoperative atrial arrhythmias, or as prophylactic if done because the patient was considered high risk for post-operative arrhythmias. Acute outcomes and longer-term freedom from atrial arrhythmias were analysed. Maze surgery was performed in 166 patients: 137 in the therapeutic group, and 29 in the prophylactic group. The most common congenital heart lesion was single ventricle for the therapeutic group (27%) and Ebstein's anomaly for the prophylactic group (76%). Surgery consisted of a right atrial maze in 63%, left atrial maze in 4%, and bilateral maze in 33%. There were no direct complications or mortality related to the maze procedure itself. For the therapeutic group, freedom from arrhythmias was 82% and 67% at 1 and 5 years post-maze. Younger age at the time of surgery correlated with a lower long-term recurrence risk. CONCLUSION: Maze procedure at the time of an elective anatomic surgery is reasonably effective to prevent and treat atrial arrhythmias in patients with congenital heart disease at short- and mid-term, with low morbidity and mortality.

Analyses of the Mode of Termination During Diagnostic Ventricular Pacing to Differentiate the Mechanisms of Supraventricular Tachycardias.

OBJECTIVES: The goal of this study was to determine the diagnostic yield of analyzing the mode of termination during ventricular overdrive pacing (VOP) to differentiate the mechanisms of supraventricular tachycardias (SVTs). BACKGROUND: The majority of the diagnostic criteria for VOP rely on successful entrainment, but termination of SVTs is common during VOP. METHODS: We studied 225 SVTs with a 1:1 atrioventricular relationship, including 34 atrial tachycardias, 67 orthodromic reciprocating tachycardias (ORTs) (including 4 ORTs using accessory pathways [APs] with decremental properties), and 124 atrioventricular nodal re-entrant tachycardias. The total pacing prematurity (TPP) needed to reset or terminate the SVT was calculated by using a simplified method, and the post-pacing interval minus the tachycardia cycle length (PPI - TCL) was predicted from the TPP. RESULTS: VOP terminated 87 SVTs (39%). No atrial tachycardias were terminated by VOP in this study. SVT termination occurred after (n = 71) or before (n = 16) atrial resetting. The predicted PPI - TCL was highly correlated with the measured PPI - TCL (r = 0.96; p < 0.001). The TPP had diagnostic accuracy equivalent to the predicted PPI - TCL. The TPP was measurable irrespective of the termination mode and correctly diagnosed ORTs with decremental APs. All ORTs using septal APs and no atrioventricular nodal re-entrant tachycardias had a TPP <125 ms. Considering other criteria evaluable in terminated SVTs, a combined criteria of a TPP <125 ms and atrial capture/termination within the fusion period were specific for ORTs using free-wall APs, except for left anterolateral/lateral sites. CONCLUSIONS: The termination analyses were useful for differential diagnoses of SVTs terminated during VOP.

Follow-up of a modified Fontan randomized trial for intraatrial reentrant tachycardia prophylaxis.

OBJECTIVE: Atrial arrhythmias represent significant morbidity and risk for mortality in Fontan patients. In a randomized trial involving patients undergoing a lateral tunnel Fontan between 1999 and 2001, Collins et al. investigated the safety and efficacy of a surgical atrial incision aimed at decreasing the incidence of intraatrial reentrant tachycardia (IART). The purpose of this study was to report the late follow-up of the aforementioned trial. DESIGN: All surviving patients previously enrolled in the randomized trial were eligible for this follow-up study. Patients' legal guardians were contacted for informed consent and data were obtained form a retrospective chart review. RESULTS: Of the 39 eligible patients, 29 were recruited: 15 in the intervention and 14 in the control groups. The median follow was 9.0 (1.2) years for the intervention group and 9.3 (1.1) years for the control group (P= .86). At most recent follow-up, there was no statistically significant difference in the demographic, echocardiographic, and electrophysiological data between the two groups. There was no late incidence of the primary outcome, IART. There were nine cases of late-onset sinus node dysfunction (SND): 5/15 in the intervention and 4/14 in the control groups (P= .99). There was only one late pacemaker implantation for early post-op SND. CONCLUSION: At late follow-up 9 years post-Fontan, IART had not occurred in either group. There was no evidence of late-onset complications related to the interventional atrial incision. Further follow-up is warranted for this cohort.