Ventricular-Pulmonary Vascular Coupling after the Total Cavopulmonary Anastomosis (Fontan)

Transcription

1 Ventricular-Pulmonary Vascular Coupling after the Total Cavopulmonary Anastomosis (Fontan) 6th International Neonatal & Childhood Pulmonary Vascular Disease Conference Fontan Physiology Single ventricular pump Series of resistors Ventricle Systemic arterial bed Pulmonary arterial bed Ventricular Morphology - Dominant LV - Dominant RV - Indeterminate - HLHS - HRHS Background - Balanced ventricles Univentricular atrioventricular connection Biventricular atrioventricular connection -Before -During -After each stage RV Morphology 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. DeCampli The Journal of Thoracic and Cardiovascular Surgery Volume 123 Objective: This study was undertaken to evaluate factors in early mortality and morbidity after the Fontan procedure between January 1, 1992, and December 31,

2 RV morphology Gentles et al. JTCVS 1997;114: Systolic function RVEF lower than LVEF (Every paper ever written) Lower ejection fraction/shape change in TA (Br Heart J 1988;60:324-31) Abnormal circumferential wall stress over 2 years Normalised if Fontan <10 years (Sluysmans et al. Circulation 1992;86: ) Force-frequency relationships The systemic vessels LV n=19 RV n=17 Normal n=13 Cheung et al. Heart 2005 Thicker veins Thinner arteries Unrelated to hemodynamics, ACE use, type of Fontan Sarkola et al. In press Heart & Vessels

3 Ventriculo-Vascular coupling Ventricular-Vascular coupling Pressure Ea Ea Ees Volume * ** * ** * p<0.01 **p<0.001 Normal Mustard Fontan * * Ea Ees Ea/Ees Khambadkone et al. Circulation 2002;106:II-358 Senzaki et al. Circulation 2002;105: Ventricular-Vascular coupling Ventricular-Vascular coupling Senzaki et al. Circulation 2002;105: Senzaki et al. Circulation 2002;105:

4 ACE inhibition Enalapril and exercise 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: ACE inhibition 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 Low preload reserve Diastolic dysfunction Pulmonary vascular bed 4

5 Preload reduction - Diastole Acute preload reduction Maintained shortening Constant LV mass Similar geometric change with BCVS Acute transition Increased τ Rychik et al JACC 1996 Penny et al CITY 1991 Wall motion abnormalities Inward AoVC AVVo motion during IVR 10% preop 80% postop Penny et al. Br Heart J 1991;66:456-9 Wall motion abnormalities Fogel et al. Am J Physiol 1995;269:H

6 Incoordinate relaxation 27 patients (7 RV) undergoing Fontan procedure Preoperative relaxation abnormality (prolonged τ) only independent predictor of length of ICU and hospital stay Border et al. JTCVS 2003;126: Increased ventricular stiffness 16 (11 RV) patients undergoing Fontan procedure Ventricular stiffness (β) from pressure area (intraop TEE) loops CT drainage and LOHS correlated with pre and postop β Garofalo et al. Circulation 2006;114: Incoordinate relaxation LV Pressure - dimension loops Incoordinate and stiff Penny et al. Br Heart J ;66: cm 6

7 Poor LV compliance Normal aging Approximate 2 mmhg rise in LVEDP every decade after 4th Increased if volume load or systemic hypertension Late changes Diastolic performance assessed ~8 years apart IVRT flow in 70% Shortened IVRT Faster e-wave deceleration Z-score z-score of E of wave IVRT DT P<0.03 P<0.01 Cheung et al. Heart

8 Diastolic compliance Pressure Ea EDPVR Normal 0.8 Mustard 0.6 Fontan EDPVR Pressure Volume Khambadkone et al. Circulation 2002;106:II-358 At peak exercise mean pulmonary arterial pressure increased from 10 to 18 mmhg (max = 8 to 27) PCWP increased from 6 to 10 mmhg (max = 7 to 19) Fontan Physiology Single ventricular pump Series of resistors Systemic arterial bed Systemic venous-pulmonary vascular bed Ventricle Pulmonary arterial bed 85 cm.s cm.s -1 -ve Ventricle +ve Lungs Redington et al. Br Heart J

9 Systemic venous-pulmonary vascular bed Hepatic veins Hsai TY et al. Circulation 2000 Lars Sondegard 2001 Pulmonary endothelial function Reduced NO production with low pulsatile stretch/shear (Busse & Fleming. J Vasc Res Hakim. Am J Physiol 1994) Pre NO N=15, p<0.005 Post NO Khambadkone et al. Circulation 2003:107; Pulmonary endothelial function Greater NO responsiveness if PBF pre-fontan Higher PVR predicted lower functional class Role of NO donor/sildenafil? Kambadkone et al. Circulation 2003 Conclusions Intrinsic abnormalities in some forms of Single ventricle Systolic function usually preserved Adverse relaxation abnormalities amplified by early and late reduction in compliance Abnormal systemic vascular properties Abnormal pulmonary vascular bed 9

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