FONTAN CIRCULATION How does the blood go round

FONTAN CIRCULATION How does the blood go round?

FONTAN CIRCULATION Systemic venous-pulmonary vascular bed 85 cm. s-1 15 cm. s-1 Redington et al. Br Heart J 1990

FONTAN CIRCULATION Pulmonary endothelial function Reduced NO production with low pulsatile stretch/shear N=15, p<0. 005 PVRI (Wu. M 2) l (Busse & Fleming. J Vasc Res 1998. Hakim. Am J Physiol 1994) Khambadkone et al. Circulation 2003: 107; 3204 -8

FONTAN CIRCULATION Pulmonary endothelial function Greater NO responsiveness if PBF pre-Fontan l Higher PVR predicted lower functional class l l Role of NO donor/sildenafil? Kambadkone et al. Circulation 2003

FONTAN CIRCULATION RV Morphology 237 The Journal of Thoracic and Cardiovascular Surgery. 2002 Volume 123 Surgery for Congenital Heart Disease Predictors of outcome after the Fontan operation: Is hypoplastic left heart syndrome still a risk factor? J. William Gaynor, MD Nancy D. Bridges, MD Mitchell Cohen, MD William T. Mahle, MD William M. De. Campli Objective: This study was undertaken to evaluate factors in early mortality and morbidity after the Fontan procedure between January 1, 1992, and December 31, 1999.

FONTAN CIRCULATION RV Morphology Gentles et al. JTCVS 1997; 114: 376 -91

FONTAN CIRCULATION RV Morphology

FONTAN CIRCULATION Systolic function LV – n=19 RV – n=17 Normal – n=13 Cheung et al. Heart 2005

FONTAN CIRCULATION Systolic function Ees Ea 14 * p<0. 01 **p<0. 001 ** 12 Normal Pressure 10 Mustard 8 ** 6 Ea 4 2 0 Volume Fontan * * Ea Ees Ea/Ees Khambadkone et al. Circulation 2002; 106: II-358

FONTAN CIRCULATION Diastolic function? Increased τ Penny et al. CITY 1990

FONTAN CIRCULATION Diastole: Incoordinate relaxation Penny et al. Br Heart J 1991 ; 66: 375 -78

FONTAN CIRCULATION Diastole: Wall motion abnormalities Fogel et al. Am J Physiol 1995; 269: H 1132 -52

FONTAN CIRCULATION Incoordinate relaxation 27 patients (7 RV) undergoing Fontan procedure l Preoperative relaxation abnormality (prolonged τ) only independent predictor of length of ICU and hospital stay l Border et al. JTCVS 2003; 126: 1760 -4

FONTAN CIRCULATION Diastole: Incoordinate relaxation Penny et al. Br Heart J 1991 ; 66: 375 -78

FONTAN CIRCULATION Diastole: Ventricular stiffness Normal aging Approximate 2 mm. Hg rise in LVEDP every decade after 4 th l Increased if volume load or systemic hypertension l

FONTAN CIRCULATION Diastole: increased stiffness? l Diastolic performance assessed ~8 years apart l IVRT flow in 70% l Shortened IVRT l P<0. 01 Faster e-wave deceleration Cheung et al. Heart 2000

FONTAN CIRCULATION Diastolic compliance Ea mm. Hg/ml Pressure EDPVR Volume Pressure Khambadkone et al. Circulation 2002; 106: II-358

FONTAN CIRCULATION

FONTAN CIRCULATION

FONTAN CIRCULATION ACE inhibition Enalapril and exercise l l l 18 patients (age 14+6 years) 4 -19 years post Fontan Randomised DB, PC, X-over study of enalapril for 10 weeks Graded treadmill exercise Kouatli et al. Circulation 1997; 96: 1507 -12

FONTAN CIRCULATION ACE inhibition l l l No change in resting Doppler indices, HR, cardiac index or exercise duration Trend to reduced CI and VO 2 Exercise induced increase in cardiac index significantly reduced with treatment Kouatli et al. Circulation 1997

FONTAN CIRCULATION Conclusions l Intrinsic abnormalities in all forms of ‘Single ventricle’ l l Systolic function usually preserved Adverse effects of relaxation abnormalities amplified by later reduction in ventricular compliance RV may be more susceptible to late Fontan failure Ventricular fibrosis may be a therapeutic target