Progression of late postoperative atrial fibrillation in patients with tetralogy of Fallot.

INTRODUCTION: ToF patients are at risk for ventricular deterioration at a relatively young age, which can be aggravated by AF development. Therefore, knowledge on AF development and its timespan of progression is essential to guide treatment strategies for AF. OBJECTIVE: We examined late postoperative AF onset and progression in ToF patients during long-term follow-up after ToF correction. In addition, coexistence of AF with regular supraventricular tachyarrhythmias (SVT) and ventricular tachyarrhythmias (VTA) was analyzed. METHODS AND RESULTS: ToF patients (N  =  29) with AF after ToF correction referred to the electrophysiology department between 2000 and 2015 were included. All available rhythm registrations were reviewed for AF, regular SVT, and VTA. AF progression was defined as transition from paroxysmal AF to (longstanding) persistent/permanent AF or from (longstanding) persistent AF to permanent AF. At the age of 44 ± 12 years, ToF patients presented with paroxysmal (N  =  14, 48%), persistent (N  =  13, 45%) or permanent AF (N  =  2, 7%). Age of AF development was similar among patients who either underwent initial shunt creation (N  =  15, 45 ± 11 [25-57] years) or primary total ToF correction (N  =  14, 43 ± 13 [26-66] years) (P  =  0.785). AF coexisted with regular SVT (N  =  18, 62%) and VTA (N  =  13, 45%). Progression of AF occurred in 11 patients (38%) within 5 ± 5 years after AF onset despite antiarrhythmic drug class II (AAD, P  =  0.052) or III (P  =  0.587) usage. CONCLUSIONS: AF in our ToF population developed at a young age and showed rapid progression. Rhythm control by pharmacological therapy was ineffective in preventing AF progression.

Ten-year outcomes of monomorphic ventricular tachycardia catheter ablation in repaired tetralogy of Fallot.

BACKGROUND: Monomorphic ventricular tachycardia (MVT) is common in adults with repaired tetralogy of Fallot (TOF), and is associated with sudden cardiac death. Management of MVT is not defined, and results of catheter ablation (CA) are limited. AIMS: To evaluate long-term outcomes of MVT CA in repaired TOF. METHODS: Thirty-four patients (mean age 32±10.3 years; 59% male) with repaired TOF underwent CA for symptomatic MVT between 1990 and 2012 in our centre; direct-current ablation (DCA) was used in 6%, radiofrequency followed by DCA in 29% and radiofrequency alone in 65%. RESULTS: Right ventricular (RV) dysfunction was present in 35% and left ventricular (LV) dysfunction in 21%. Mean numbers of clinical and induced MVTs were 1 and 2, respectively. Mean VT rate was 225±95bpm. Ablation targeted a single site (range 1-2), which was RV outflow tract in 85%. Primary success, defined as ventricular tachycardia (VT) termination during CA and final non-inducibility, was obtained in 82%. Seven patients (21%) required redo ablation in the first 3 months (before 2004; DCA). No death related to CA occurred. Mean follow-up time was 9.5±5.2 years. Antiarrhythmic therapy was discontinued in 71%. There were two cases of sudden cardiac death and four VT recurrences. Freedom from death and arrhythmia recurrence was 94% at 5 years, 81% at 10 years and 70% at 20 years. Global survival was 91% at 20 years. Baseline LV ejection fraction<60% was significantly associated with ventricular arrhythmia recurrence (hazard ratio 16.4, 95% confidence interval 1.8-147; P=0.01). CONCLUSIONS: CA can safely address macroreentrant MVT in repaired TOF patients with an acceptable long-term rate of recurrence in this high-risk population. Anatomical classification of isthmuses with electroanatomical mapping provides reproducible endpoints for CA. Attention should be given to LV systolic function in risk assessment and selection of candidates for implantable cardioverter-defibrillator.

Arrhythmias and sudden death among older children and young adults following tetralogy of Fallot repair in the current era: are previously reported risk factors still applicable?

BACKGROUND: Young adult patients (pts) with repaired tetralogy of Fallot (TOF) remain at risk for arrhythmias (Ar) and sudden cardiac death (SCD). Based on past studies with earlier pt subsets, Ar/SCD events were associated with right ventricular (RV) systolic pressures >60 mm Hg, outflow tract gradients >20 mm Hg, and QRS duration >180 ms. However, there are limited recent studies to evaluate these risk factors in the current patient generation. METHODS: Patients with TOF followed over the past 50 years were grouped by presence of any arrhythmias (group 1), absence of arrhythmias (group 2), and presence of SCD or significant ventricular arrhythmias (group 3) and correlated with current pt age, gender, age at repair, repair types, echocardiogram, cardiac magnetic resonance imaging, electrocardiogram/Holter, hemodynamics, and electrophysiology findings. RESULTS: Of 109 pts, 52 were male aged 17-58 years. Of these, 59 (54%) had Ar, two of whom had SCD. These 59 pts were chronologically older at the time of analysis, with repair at an older age and wider QRS duration (78-240, mean 158 ms) when compared with those without Ar. However, there was no correlation with surgical era, surgical repair, gender, RV pressure >60 mm Hg, right ventricular outflow tract gradient >20 mm Hg, or RV end-diastolic volume on CMRI. CONCLUSIONS: Ar/SCD risk continues to correlate with repair age and advancing pt age. QRS duration is longer in these patients but at a shorter interval (mean 158 ms) and less RV pressure (mean 43 mm Hg) than previously reported. In the current TOF patient generation, neither surgical era, type of repair, RV outflow gradient nor RV volume correlate with Ar/SCD. Electrophysiologic testing to verify and identify arrhythmias remains clinically effective.