BACKGROUND: Patients with corrected tetralogy of Fallot (cTOF) have an increased risk of ventricular tachycardia (VT) and sudden death, but known risk factors have a limited prognostic value. Additionally, little is known about electrophysiological and electro-anatomical parameters of the right ventricle (RV) in these patients. METHODS: Ambispective, longitudinal and observational study of patients with cTOF undergoing electro-anatomical mapping of RV at the University Hospital Vall d'Hebron between March 2006 and December 2016. RESULTS: 43 patients (67% men, mean age 34.1 ± 10.0 years) were included and divided into two groups according to the absence (group A, n = 28) or presence (group B, n = 15) of clinical or induced VT. Group B had a higher HV interval (60.9 ± 15.1 vs 48.5 ± 7.9 ms, p = 0.001), a superior percentage of HV ≥ 55 ms (73% vs 19%, p = 0.001), a longer RV activation time (133.0 ± 34.8 vs 109.8 ± 27.8 ms, p = 0.017) and a higher prevalence of double potentials (DP) (93% vs 54%, p = 0.015). Patients with complex ventricular ectopic beats showed a greater extent of scar tissue (voltage <0.5 mV) in the whole RV (area 30.7 ± 12.1 vs 20.1 ± 15.6 cm2, p = 0.054 and percentage 13.1 ± 6.0 vs 7.3 ± 5.6%; p = 0.035) and in the RV outflow tract (RVOT) (area 22.3 ± 12.6 vs 15.6 ± 14.2 cm2, p = 0.033 and percentage 11.5 ± 5.1 vs 5.7 ± 4.9%, p = 0.010). The QRS interval showed a positive correlation with the total scar area (r = 0.35, p = 0.027) and the RV activation time (r = 0.67, p <0.001). In the DP group, the QRS interval (166.1 ± 25.4 vs 147.8 ± 24.3 ms, p = 0.004), the RV activation time (126.6 ± 34.6 vs 99.9 ± 19.4 ms, p = 0.003) and the scar tissue extension (25.6 ± 16.4 vs. 15.3 ± 12.2 cm2, p = 0.038) were higher. It was documented an association between hemodynamic variables of RV and left ventricular (LV) and RV electrophysiological parameters: a) Worse RV ejection fraction (EF) in those patients with HV ≥ 55 ms (40.1 ± 9.4 vs 47.3 ± 7.4%, p = 0.025); b) Correlation between scar extension and indexed telediastolic volume (VTDi) of RV (total scar area r = 0.48, p = 0.003 and RVOT scar area r = 0.54, p = 0.001), telediastolic diameter (DTD) of RV (RVOT scar area r = 0.38, p = 0.017), RV systolic function (total scar area and tricuspid tissue Doppler [DTI] r = – 0.40, p = 0.019; total scar area and RVEF r = – 0.58, p < 0.001 and RVOT scar area and RVEF r= – 0,58, p < 0.001), and LVEF (total scar area r = – 0.56, p = 0.001 and RVOT scar area r = – 0.54, p = 0.001) and c) Correlation between RV activation time and RV dilation (DTD r = 0.36, p = 0.024 and VTDi r = 0.45, p = 0.005) and RV systolic dysfunction (Tricuspid annular plane systolic excursion r = – 0.47, p = 0.002, tricuspid DTI r = – 0.43, p = 0.011 and RVEF r = – 0.45, p = 0.005). Five patterns of RV activation have been identified. Patients with QRS <120 ms showed an onset of activation in the apex and an ending in the anterior RVOT. The other patterns could not be predicted by QRS duration or morphology.
| Date of Award | 25 Apr 2017 |
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| Original language | Spanish |
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| Supervisor | Angel Moya Mitjans (Director) & Maria Pilar Tornos Mas (Tutor) |
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