Mechanism and Ablation of Arrhythmia Following Total Cavopulmonary Connection

Circ Arrhythm Electrophysiol. 2015 Jan 12. pii: CIRCEP.114.001758. [Epub ahead of print]

Mechanism and Ablation of Arrhythmia Following Total Cavopulmonary Connection.

Correa R1Sherwin ED1Kovach J1Mah DY1Alexander ME1Cecchin F1Walsh EP1Triedman JK1Abrams DJ2.

Comment: This study addresses identification of the mechanisms of arrhythmia following TCPC as well as assessing feasibility, safety and success of ablation.  52 patients were identified, 48 of whom were intracardiac and 4 extracardiac, 2 of whom had undergone surgical conversion from atriopulmonary Fontan and arrhythmia surgery.  Patients had EP studies for palpications, syncope, documented arrhythmia, cardiac arrest, and asymptomatic ventricular pre-excitation.  Eighty arrhythmia substrates were identified.  There were 25 macroreentrant atrial circuits in 17 patients, 14 of which were cavotricuspid or cavomitral isthmus dependent.  There were 8 focal atrial tachycardias in 5 patients; 6 foci were in the intracardiac tunnel.  Thirteen AVNRT patterns were seen in 8 patients.  Orthodromic AVRT was seen in 4 patients, 2 of whom had manifest pre-excitation.  Twin AV nodes were involved in 4 tachycardias in 3 patients.  Twenty-one atrial arrhythmias were induced in 14 patients that could not be mapped in sufficient detail to define the mechanism.  Ventricular tachycardia was found in 5 patients, all of whom had no atrial arrhythmias found.  Five patients had no inducible arrhythmias despite documented atrial tachycardia in 3 of them.  32 of the 52 patients had ablations with 76% success, 9% partial success and 9% failure.  Of the patients with follow up data, 50% had arrhythmia recurrence.  Despite this, there was a decrease in arrhythmia severity in the short term and a trend to decrease in the longer term, even in patients with arrhythmia recurrence.  This study elucidates the broad variety of tachycardias in patients with TCPC and demonstrates that successful ablation can be performed.