Arrhythmias and Sudden Death among Older Children and Young Adults Following Tetralogy of F allot Repair in the Current Era: Are Previously Reported Risk Factors Still Applicable?

Abstract

Background Young adult patients (pts) with repaired tetralogy of F allot ( TOF ) remain at risk for arrhythmias ( A r) and sudden cardiac death ( SCD ). Based on past studies with earlier pt subsets, A r/ 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/ H olter, hemodynamics, and electrophysiology findings. Results Of 109 pts, 52 were male aged 17–58 years. Of these, 59 (54%) had A r, 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 A r. 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 A r/ 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 A r/ SCD . Electrophysiologic testing to verify and identify arrhythmias remains clinically effective.