Abstract 1943: The Effects of Pulmonary Valve Replacement in Adult Patients with Tetralogy of Fallot
Introduction: In adult patients with tetralogy of Fallot, pulmonary valve regurgitation may cause right ventricular failure and lethal arrhythmias. Electrocardiography and cardiac magnetic resonance imaging (CMR) may identify which of these patients are vulnerable to ventricular arrhythmias. We studied the effects of pulmonary valve replacement on the electrocardiogram, right ventricular volume and the relation of these measurements with arrhythmias.
Methods: Thirty Fallot patients (age 32 ± 9 years, 19 male) eligible for pulmonary valve replacement were studied with cardiac magnetic resonance imaging (CMR) before and 6 months after pulmonary valve replacement. Electrocardiograms obtained during initial and follow-up CMR were analyzed and the occurrence of ventricular arrhythmias was studied for 5.5 ± 1.9 years after pulmonary valve replacement.
Results: Pulmonary valve replacement reduced right ventricular end-diastolic volume (RV EDV) from 322 ± 87 to 215 ± 57 ml (P ± 0.0001). QRS duration decreased from 158 ± 34 to 153 ± 32 ms (P = 0.002). The spatial QRS-T angle normalized from 117 ± 34 to 100 ± 35°, P = 0.0004 (normal < 105°). QT dispersion did not change significantly. T-wave amplitude decreased from 376 ± 121 to 329 ± 100 μV (P = 0.01) and T-wave area decreased from 43 ± 15 to 38 ± 13 μV·s (P = 0.02). Changes in T-wave amplitude and -area were most prominent in the right precordial leads overlying the RV. Three patients had sustained ventricular arrhythmias and one patient died suddenly during follow-up. All these patients had a QRS duration > 160 ms. The specificity for the prediction of arrhythmias could be improved by combining the QRS duration with a RV EDV > 220 ml, a QRS-T angle > 100° or a QT dispersion > 60 ms.
Conclusion: Pulmonary valve replacement in Fallot patients with dilated right ventricles has beneficial electrocardiographic and structural effects. The combination of the QRS duration with RV volume or a repolarization measure may be used to identify patients with potentially lethal arrhythmias.