Heart rate turbulence in adults with repaired tetralogy of Fallot

• Published in: International journal of cardiology 2009-07, Vol.135 (3), p.308-314
• Main Authors: Davos, Constantinos H, Moutafi, Antonia C, Alexandridi, Anastasia, Petropoulou, Evdokia, Varela, Emily, Chamakou, Aikaterini C, Francis, Darrel P, Kilner, Philippe J, Piepoli, Massimo F, Gatzoulis, Michael A
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Factors; Aged; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Arrhythmia; Autonomic nervous system; Biological and medical sciences; Cardiac dysrhythmias; Cardiology. Vascular system; Cardiovascular; Emergency and intensive care: neonates and children. Prematurity. Sudden death; Female; Heart; Heart Rate - physiology; Humans; Intensive care medicine; Male; Medical sciences; Middle Aged; Predictive Value of Tests; Sudden death; Surgery; Tetralogy of Fallot; Tetralogy of Fallot - mortality; Tetralogy of Fallot - physiopathology; Tetralogy of Fallot - surgery; Turbulence; Young Adult
• ISSN: 0167-5273; 1874-1754
• DOI: 10.1016/j.ijcard.2008.03.096

Abstract Background Tetralogy of Fallot (ToF) patients face an increased risk of sudden cardiac death late after repair. Heart rate turbulence (HRT) indices are well-known predictors of sudden cardiac death. We aimed to estimate whether HRT is impaired in repaired ToF patients compared to healthy controls and relate those HRT parameters to already recognized prognostic markers. Methods Continuous ECG recordings were performed in 19 patients late after ToF repair (36.3 ± 12.4 years, 26.6 ± 7.1 years after repair) and 20 age-matched healthy controls (40.8 ± 8.1 years). Turbulence slope (TS) and onset (TO), frequency and time domain heart rate variability parameters and QRS duration were estimated. Volumes of the right (RV) and left ventricle (LV) and ejection fraction (EF) were assessed by cardiovascular magnetic resonance imaging. Cardiopulmonary exercise testing was used to estimate peak oxygen consumption (VO2 ) and VE/VCO2 slope. Results TS (15.95 ± 9.41 vs 28.73 ± 12.24 ms/RRI, p = 0.0007) and TO (− 0.98 ± 2.06% vs − 3.45 ± 3.25%, p = 0.007) were found to be significantly different between ToF patients and controls. TO correlated with LVEF ( r = 0.47, p < 0.05), LVSVi ( r = 0.50, p = 0.03), RVEF ( r = 0.53, p = 0.02), peak VO2 ( r = 0.50, p = 0.05), VE/VCO2 slope ( r = − 0.55, p = 0.03) and with heart rate variability frequency domain indices (log LF, r = 0.47, p = 0.04, log HF, r = 0.56, p = 0.01). Conclusion HRT indices are impaired in ToF patients late after surgical repair compared to healthy controls and relate to coexisting haemodynamic, ventilatory and autonomic impairment. A clinical prognostic role of HRT may be speculated, which warrants further investigation.