Acute right ventricular restrictive physiology after repair of tetralogy of Fallot: association with myocardial injury and oxidative stress.
BACKGROUND
Acute right ventricular (RV) restrictive physiology after tetralogy of Fallot repair results in low cardiac output and a prolonged stay in the intensive care unit (ICU). However, its mechanism remains uncertain.


RESULTS
In the first 24 hours after tetralogy of Fallot repair (n=11 patients), serial prospective measurements were performed of cardiac troponin T, indexes of NO production (NO(2)(-) and NO(3)(-) combined as NOx), and iron metabolism and antioxidants. RV diastolic function was assessed by transthoracic Doppler echocardiography. Patients who had a long stay in the ICU were characterized by restrictive RV physiology (nonrestrictive group [n=7]: 3.0+/-0.6 days [mean+/-SD]; restrictive group [n=4]: 10.7+/-3.1 days). Troponin T peak concentration and the area under its concentration-time curve (AUC) were higher in the restrictive RV group (peak: restrictive group 17. 0+/-2.8 microg/L, nonrestrictive group 10.4+/-4.6 microg/L, P<0.03; AUC: restrictive group 268.8+/-73.6 microg. h(-1). L(-1), nonrestrictive group 136.2+/-48.3 microg. h(-1). L(-1), P<0.03). Plasma NOx/creatinine concentrations were higher in the restrictive group than the nonrestrictive group at 2 hours after bypass (restrictive group 1.3+/-0.4, nonrestrictive group 0.8+/-0.2; P=0. 04) but were similar by 24 hours. Iron loading peaked 2 to 10 hours after bypass and was more severe in the restrictive group (peak transferrin saturation: restrictive group 83.9+/-13.0%, nonrestrictive group 58.3+/-16.2%, P=0.05; minimum total iron-binding capacity: restrictive group 0.59+/-0.21%, nonrestrictive group 0.76+/-0.06%, P=0.04; minimum iron-binding antioxidant activity to oxyorganic radicals: restrictive group 9. 5+/-22.4%, nonrestrictive group 50.6+/-11.4%, P=0.01).


CONCLUSIONS
After tetralogy of Fallot repair, acute restrictive RV physiology is associated with greater intraoperative myocardial injury and postoperative oxidative stress with severe iron loading of transferrin.
Chaturvedi
R R
RR
Department of Paediatric Cardiology, Royal Brompton Hospital, National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London. UK.
Shore
D F
DF
Lincoln
C
C
Mumby
S
S
Kemp
M
M
Brierly
J
J
Petros
A
A
Gutteridge
J M
JM
Hooper
J
J
Redington
A N
AN
D002675:Child, Preschool; D003971:Diastole; D006801:Humans; D007223:Infant; D007431:Intraoperative Complications / Q000209:etiology*; D007501:Iron / Q000378:metabolism; D019190:Iron Overload / Q000209:etiology; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D011446:Prospective Studies; D013771:Tetralogy of Fallot / Q000503:physiopathology / Q000601:surgery*; D020107:Troponin T / Q000097:blood; D018497:Ventricular Dysfunction, Right / Q000209:etiology*
D020107:Troponin T; D009569:Nitric Oxide; D007501:Iron