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Introduction:Evidence suggested minimal advantage of performing coil embolization in aortopulmonary collateral arteries (APCA) before the Fontan procedure, whereas advanced imaging modality demonstrated that APCA flow in bidirectional cavopulmonary shunt (BCPS) circulation accounted for over 30% of the aortic blood flow and highlighted its possible benefits. As ventricles with diastolic dysfunction might not operate additional volume loading, we hypothesized that the benefit of APCA embolization before the Fontan procedure particularly depends on the preoperative ventricular diastolic property.Methods:During pre-Fontan cardiac catheterization, the cardiovascular property was evaluated in 33 BCPS patients. The impact of APCA embolization on the postoperative course and hemodynamic parameters were analyzed in relation to the pre-Fontan cardiovascular property.Results:The Fontan procedure was performed at the age of 2.5?0.6 years. Embolization was performed using vascular coils for 24 (71%) patients until contrast delivered from the ascending aorta could not detect the pulmonary artery. Compared to patients without embolization, those with embolization had similar age, pulmonary arterial pressure, cardiac index, and central venous pressure both before and after the Fontan procedure. While the duration of pericardial drainage in those with embolization was shorter than those without (p=0.011), intensive care unit (ICU) stay, hospital stay, and duration of chest drainage were similar in the two groups. After adjusting for diastolic stiffness beta by analysis of variance, APCA embolization was associated with shorter ICU stay (p=0009), hospital stay (p=0.016), and duration of pericardial drainage (p=0.086). Interestingly, the duration of chest drainage was more strongly affected by diastolic stiffness beta than coil embolization (p=0.056).Conclusions:The impact of APCA embolization on the postoperative course after the Fontan procedure is affected by the ventricular diastolic property. Studies on rationale of beneficial effect and candidate selection should be performed to maximize the cost-benefit balance.

Introduction:Impaired preload reserve coupled with augmented venous congestion is increasingly subject to therapies to prevent cardiovascular remodeling and end organ failure in the Fontan circulation. As the atrial rhythm is often disrupted and replaced by alternative rhythm in the Fontan circulation, atrioventricular synchronicity might be compromised, and affect Fontan physiology. We hypothesized that the atrioventricular synchronization ameliorates Fontan circulation.Methods:Catheter-based hemodynamic study was performed in 32 Fontan patients at baseline and after atrial pacing with minimum possible heart rate (HR). Variation of atrioventricular conduction time (AVCT) was measured and its impact on hemodynamics was analyzed. Thirty patients with biventricular circulation were enrolled as control and their relationships between AVCT and hemodynamics were compared with those of Fontan patients.Results:Under atrial pacing (baseline: 101?16 bpm, pacing: 119?17 bpm), cardiac index increased whereas stroke volume index (SVI) mildly decreased which was attributed to increased effective arterial elastance with similar end-systolic elastance. While changes in SVI and end diastolic volume index (EDVI) were statistically similar, AVCT in the Fontan group markedly increased as compared with controls (p=0.0040). Consistent with the finding that short AVCT is associated with dyssynchronicity of atrial and ventricular pressure rises, SVI in 44% of Fontan patients increased as compared with 29% in controls. Indeed, AVCT increase with pacing was positively correlated with increasing EDVI (p=0.044) as well as SVI (p=0.0015) in the Fontan patients, whereas it was negatively correlated in controls (p=0.042), suggesting enhanced importance of securing AVCT in the Fontan circulation. After adjusting for HR (p=0.017, ?=-0.43) by analysis of covariance, AVCT increase (p=0.0026, ?=0.57) strongly contributed to increased SVI in the Fontan patients.Conclusions:Securing AVCT by atrial pacing helped optimization of AV synchronicity as evident by secured EDVI and SVI in part of Fontan patients. Heart rate optimization coupled with securing AVCT might be the therapeutic option to counteract impaired preload reserve in the Fontan circulation.