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BACKGROUND: Despite a rigorous screening process, including cardiac catheterization, a subset of patients with a single right ventricle (SRV) demonstrates suboptimal short-term outcomes after the Fontan operation. The goal of this study was to perform a comprehensive assessment of diastolic function in pre-Fontan patients with an SRV using invasive reference-standard measures and determine their associations with post-Fontan outcomes. METHODS AND RESULTS: Children aged 2 to 6 years with SRV physiology undergoing pre-Fontan heart catheterization were recruited prospectively. Patients were divided into those who had an optimal or suboptimal outcome. A suboptimal outcome was defined as length of stay ≥14 days or heart transplant/cardiac death in first year after Fontan. Patients underwent pressure-volume loop analysis using reference-standard methods. The measure of ventricular stiffness, ß, was obtained via preload reduction. Cardiac magnetic resonance imaging for extracellular volume and serum draws for matrix metalloproteinase activity were performed. Of 19 patients with an SRV, 9 (47%) had a suboptimal outcome. Mean age was 4.2±0.7 years. Patients with suboptimal outcomes had lower ventricular stiffness (0.021 [0.009-0.049] versus 0.090 [0.031-0.118] mL-1; P=0.02), lower extracellular volume (25% [28%-32%] versus 31% [28%-33%]; P=0.02), and lower matrix metalloproteinase-2 (90 [79-104] versus 108 [79-128] ng/mL; P=0.01) compared with patients with optimal outcomes. The only invasive measure that had an association with suboptimal outcome was ß (P=0.038). CONCLUSIONS: Patients with an SRV with suboptimal outcome after the Fontan operation had lower ventricular stiffness and evidence of maladaptive extracellular matrix metabolism compared with patients with optimal outcome. This appears to be a novel phenotype that may have important clinical implications and requires further study.

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Patients with Fontan circulation insidiously develop congestive hepatopathy related to chronically reduced cardiac output and central venous hypertension, also known as Fontan-associated liver disease (FALD). Fontan pathway obstruction is increasingly detected and may accelerate FALD. The impact of conduit stent angioplasty on FALD is unknown. Retrospective, single-center review of patients with Fontan circulation who underwent conduit stent angioplasty at cardiac catheterization over 5-year period. Demographics and cardiac histories were reviewed. Labs, liver ultrasound elastography, echocardiogram, hemodynamic and angiographic data at catheterization were recorded pre- and post-stent angioplasty. Primary outcome was change in hepatic function via MELD-XI scores and liver stiffness (kPa), with secondary outcomes of ventricular function, BNP, and repeat catheterization hemodynamics. 33 patients underwent Fontan conduit stent angioplasty, 19.3 ± 7.0 years from Fontan operation. Original conduit diameter was 19.1 ± 1.9 mm. Prior to angioplasty, conduit size was reduced to a cross-sectional area 132 (91, 173) mm2 and increased to 314 (255, 363) mm2 post-stent. Subjects' baseline median MELD-XI of 11 (9, 12) increased to 12 (9, 13) at 19 ± 15.5 months post-angioplasty (n = 22, p = 0.053). There was no significant change in liver stiffness at 12.1 ± 8.9 months post-angioplasty (n = 15, p = 0.13). Median total bilirubin significantly increased (1.4 [0.9, 1.8]), from baseline 1.1 [0.7, 1.5], p = 0.04), as did median BNP (41 [0, 148] from baseline 34 [15, 79]; p = 0.02). There were no significant changes in ventricular function or repeat invasive hemodynamics (n = 8 subjects). Mid-term follow-up of Fontan subjects post-conduit stent angioplasty did not show improvements in non-invasive markers of FALD.

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Progressive ventricular dysfunction is not uncommon in patients with univentricular hearts as they age. In the acute setting vasoactive support can be employed, but is not always sufficient and patients occasionally require mechanical support. We report the successful implantation and subsequent challenges of a percutaneous Abiomed Impella ventricular assist device as a rescue therapy for a 15-year old-patient with Fontan circulation and severe ventricular dysfunction after cardiac arrest.

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BACKGROUND: Pediatric heart transplant recipients are at risk for increased left ventricular (LV) diastolic stiffness. However, the noninvasive evaluation of LV stiffness has remained elusive in this population. The objective of this study was to compare novel echocardiographic measures of LV diastolic stiffness versus gold-standard measures derived from pressure-volume loop (PVL) analysis in pediatric heart transplant recipients. METHODS: Patients undergoing left heart catheterization were prospectively enrolled. PVLs were obtained via conductance. The end-diastolic pressure-volume relationship was obtained via balloon occlusion. The stiffness constant, ß, was calculated. Echocardiographic measures of diastolic function were derived from spectral and tissue Doppler and two-dimensional speckle-tracking. Ventricular volumes were measured using three-dimensional echocardiography. The novel echocardiographic estimates of ventricular stiffness included E:e'/end-diastolic volume (EDV) and E:early diastolic strain rate/EDV. RESULTS: Of 24 children, 18 were heart transplant recipients. Six control patients had hemodynamically insignificant patent ductus arteriosus or coronary fistula. The mean age was 9.1 ± 5.6 years. Median end-diastolic pressure was 9 mm Hg (interquartile range, 8-13 mm Hg). Lateral E:e'/EDV (r = 0.59, P < .01), septal E:e'/EDV (r = 0.57, P < .01), and (E:circumferential early diastolic strain rate)/EDV (r = 0.54, P < .01) correlated with ß. Lateral E:e'/EDV displayed a C statistic of 0.93 in detecting patients with abnormal LV stiffness (ß > 0.015 mL-1). A lateral E:e'/EDV of >0.15 mL-1 had 89% sensitivity and 93% specificity in detecting an abnormal ß. CONCLUSIONS: Echocardiographic estimates of ventricular stiffness may be accurate compared with the gold standard in pediatric heart transplant recipients. The clinical usefulness of these noninvasive measures in assessing LV stiffness merits further study in children.

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Aims: The relationship between echocardiographic measures of left ventricular (LV) systolic function and reference-standard measures have not been assessed in children. The objective of this study was to assess the validity of echocardiographic indices of LV systolic function via direct comparison to a novel composite measure of contractility derived from pressure-volume loop (PVL) analysis. Methods and results: Children with normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. A composite invasive composite contractility index (ICCI) was developed using data reduction strategies to combine four measures of contractility derived from PVL analysis. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Conventional and speckle-tracking echocardiographic measures of systolic function were measured. Of 24 patients, 18 patients were heart transplant recipients, 6 patients had a small patent ductus arteriosus or small coronary fistula. Mean age was 9.1 ± 5.6 years. Upon multivariable regression, longitudinal strain was associated with ICCI (ß = -0.54, P = 0.02) while controlling for indices of preload, afterload, heart rate, and LV mass under baseline conditions. Ejection fraction and shortening fraction were associated with LV mass and load indices, but not contractility. Conclusion: Speckle-tracking derived longitudinal strain is associated ICCI in children with normal loading conditions. Longitudinal measures of deformation appear to accurately assess LV contractility in children.

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Hybrid Norwood palliation is gaining acceptance as an alternative to open Norwood palliation in high-risk neonates with hypoplastic left heart syndrome. Aortic dissection after hybrid Norwood palliation is a rare but ominous complication that has not been reported.

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OBJECTIVE: Speckle tracking echocardiography (STE) may be a useful modality for assessing ventricular performance in patients with single ventricle physiology. However, STE's ability to accurately assess ventricular performance in this population is unknown. The objective of this study was to perform a preliminary comparison of STE measures of myocardial deformation to reference standard measures of function derived from pressure-volume loop (PVL) analysis. DESIGN: This was a secondary analysis of a prospective study investigating PVLs in patients with Fontan physiology. PVLs were recorded using microconductance catheters. PVL indices included end-systolic elastance (Ees), arterial elastance (Ea), ventriculo-arterial coupling (Ea/Ees), and the isovolumic relaxation time constant (tau). Patients were included if they had an echocardiogram within 1 month of their catheterization. STE was performed retrospectively using vendor independent software. RESULTS: Seventeen patients had echocardiograms available for analysis, 12 were right ventricular (RV) dominant. The median age was 8 years (IQR 5-17 years). Circumferential strain (r=-.72, P≤.01) and strain rate (r=-.61, P=.04) correlated with Ea/Ees in those with RV-dominant morphology. Longitudinal strain rate correlated with Ees in those with LV-dominant morphology (r=-.98, P≤.01). Longitudinal EDSR correlated with tau in those with LV-dominant morphology (r=-.90, P=.04). CONCLUSIONS: In this limited sample, circumferential measures of deformation correlated with PVL measures better in patients with RV morphology, while longitudinal measures correlated better with PVL measures in patients with LV morphology. Further validation and investigation into the clinical usefulness of these measures are warranted.

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Neonates with hypoplastic left heart syndrome and high-risk factors for an open Norwood procedure may benefit from a hybrid stage I procedure. The presence of a giant patent ductus arteriosus prevents safe deployment of the ductus arteriosus stent. We describe a new technique that involves banding the patent ductus arteriosus, therefore allowing stent implantation during hybrid stage I palliation.

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BACKGROUND: The accuracy of echocardiography in evaluating left ventricular contractility has not been validated in children. The objective of this study was to compare echocardiographic measures of contractility with those derived from pressure-volume loop (PVL) analysis in children. METHODS: Patients with relatively normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. The gold-standard measure of contractility, end-systolic elastance (Ees), was obtained via balloon occlusion of one or both vena cavae. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Single-beat estimations of echocardiographic Ees were calculated using four different methods. These estimates were calculated using a combination of noninvasive blood pressure readings, ventricular volumes derived from three-dimensional echocardiography, and Doppler time intervals. RESULTS: Of 24 patients, 18 patients were heart transplant recipients, and six patients had small patent ductus arteriosus or small coronary fistulae. The mean age was 9.1 ± 5.6 years. The average invasive Ees was 3.04 ± 1.65 mm Hg/mL. Invasive Ees correlated best with echocardiographic Ees by the method of Tanoue (r = 0.85, P < .01), with a mean difference of -0.07 mm Hg/mL (95% limits of agreement, -2.0 to 1.4 mm Hg/mL). CONCLUSIONS: Echocardiographic estimates of Ees correlate well with gold-standard measures obtained via conductance catheters in children with relatively normal loading conditions. The use of these noninvasive measures in accurately assessing left ventricular contractility appears promising and merits further study in children.

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UNLABELLED: Sildenafil has been reported to improve exercise capacity in Fontan patients, but the physiologic mechanisms behind these findings are not completely understood. The objective of this study was to study the acute effect of sildenafil on pressure-volume loop (PVL) measures of ventricular function in Fontan patients. Patients after Fontan operation who were presenting for a clinically indicated catheterization were enrolled. Patients were randomized in a double-blinded fashion to receive placebo (n = 9) or sildenafil (n = 10) 30-90 min prior to catheterization. PVLs were recorded using microconductance catheters at baseline and after infusion of dobutamine (10 mcg/kg/min). The primary outcome was change in ventriculoarterial (VA) coupling. For the entire cohort, VA coupling trended toward improvement with dobutamine (1.4 ± 0.4 to 1.8 ± 0.9, p = 0.07). End-systolic elastance showed improvement (2.6 ± 0.9 to 3.8 ± 1.4 mmHg m(2)/ml, p < 0.01) with dobutamine infusion. The cohorts had similar VA coupling at baseline (p = 0.32), but the sildenafil cohort trended toward having less of an improvement in VA coupling with dobutamine stress (p = 0.06). There were no differences between PVL measures of systolic or diastolic function between treatment groups, both at baseline and after dobutamine infusion. Patients with Fontan circulation had improved contractility and trended toward improvement in VA coupling with dobutamine stress. Acute sildenafil administration was not associated with improved PVL measurements of ventricular function in this population. These results suggest that clinical improvements seen with administration of sildenafil in Fontan patients are not associated with an acute improvement in ventricular function. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov ; Clinicaltrials.gov Identifier: NCT01815502.

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BACKGROUND: Low superior vena cava (SVC) blood flow has recently been identified as a marker for bidirectional superior cavopulmonary connection (SCPC) failure and death. Prior innominate vein occlusion is considered a significant anatomic risk factor for SCPC failure. We therefore evaluated the outcomes of infants who underwent SCPC with known upper-body venous obstruction. METHODS: Between February 1995 and June 2014, SCPC was carried out in 8 patients who had either a single SVC with known prior occlusion of the innominate vein (n = 6) or bilateral SVCs without a bridging vein with occlusion of one SVC (n = 2). The cause of the occlusion was an indwelling catheter in 5 patients. These patients were compared with 8 patients with normal upper-body venous drainage who underwent SCPC. Patients were evaluated for preoperative risk factors (including SVC size, pulmonary artery size, Nakata index, pulmonary vascular resistance), operative factors, and clinical outcomes to determine the impact of prior upper-body venous occlusion on SCPC failure or death. RESULTS: There were no significant differences in preoperative risk factors between the two groups, except for a significantly lower Nakata index in the study group with a trend toward smaller pulmonary artery branch size. There were no SCPC takedowns or mortalities. There was no significant difference in postoperative length of stay (median of 7 days [range, 5 to 32 days] versus 5 days [range, 4 to 32 days]; p = 0.17. Study patients had a lower mean systemic oxygen saturation at discharge, 81% versus 85% (p = 0.05). In the study group, at a median follow-up of 42 months, 3 patients underwent successful Fontan completion and 5 are still awaiting Fontan completion. CONCLUSIONS: Although patients with prior upper-body venous obstruction may have lower systemic oxygen saturations at hospital discharge, they do not demonstrate an increased SCPC failure or mortality rate. Innominate vein occlusion or its equivalent in patients with bilateral SVCs should not preclude the performance of SCPC. Physiologic rather than anatomic evaluation of preoperative systemic venous return may be more useful to predict outcome after SCPC.

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OBJECTIVES: This project evaluated the implementation of use of the StatLock stabilization device (Bard Access Systems, Inc, Salt Lake City, Utah) for peripherally inserted central catheters (PICCs) in pediatric cardiology patients. The aim was to implement the use of the StatLock device and evaluate its effects on the following 4 outcomes: incidence of dislodgement, infection, catheter dwell time, and the number of catheter replacements. The primary goal was to determine whether the StatLock device offered advantages over tape and sutures. METHODS: A quality improvement design was used to evaluate whether the use of the StatLock stabilization device for PICC securement on 30 pediatric cardiology patients decreased the number of PICC complications compared with 30 historical comparison patients. RESULTS: The comparison group had a significantly higher number of catheter dislodgements (n = 16; 59.3%) than the StatLock group (n = 8; 30.8%; P = .035). The comparison group did not have a significantly higher number of catheter replacements (n = 16; 59.3%) than the StatLock group (n = 10; 34.5%; P = .10). No significant differences were found in the rate of infection or in the catheter dwell time between the 2 groups (StatLock group, mean ± SD = 33.13 ± 22.71 days; comparison group, mean ± SD = 28.10 ± 24.83 days; P > .20). CONCLUSIONS: Use of the StatLock device resulted in better outcomes when compared with the use of sutures, and it provided a more effective way to stabilize and secure PICCs.

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OBJECTIVE: To compare the interstage cardiac catheterization hemodynamic and angiographic findings between shunt types for the Pediatric Heart Network Single Ventricle Reconstruction trial. The trial, which randomized subjects to a modified Blalock-Taussig shunt (MBTS) or right ventricle-to-pulmonary artery shunt (RVPAS) for the Norwood procedure, demonstrated the RVPAS was associated with a smaller pulmonary artery diameter but superior 12-month transplant-free survival. METHODS: We analyzed the pre-stage II catheterization data for the trial subjects. The hemodynamic variables and shunt and pulmonary angiographic data were compared between shunt types; their association with 12-month transplant-free survival was also evaluated. RESULTS: Of 549 randomized subjects, 389 underwent pre-stage II catheterization. A smaller size, lower aortic and superior vena cava saturation, and higher ventricular end-diastolic pressure were associated with worse 12-month transplant-free survival. The MBTS group had a lower coronary perfusion pressure (27 vs 32 mm Hg; P<.001) and greater pulmonary blood flow/systemic blood flow ratio (1.1 vs 1.0, P=.009). A greater pulmonary blood flow/systemic blood flow ratio increased the risk of death or transplantation only in the RVPAS group (P=.01). The MBTS group had fewer shunt (14% vs 28%, P=.004) and severe left pulmonary artery (0.7% vs 9.2%, P=.003) stenoses, larger mid-main branch pulmonary artery diameters, and greater Nakata indexes (164 vs 134, P<.001). CONCLUSIONS: Compared with the RVPAS subjects, the MBTS subjects had more hemodynamic abnormalities related to shunt physiology, and the RVPAS subjects had more shunt or pulmonary obstruction of a severe degree and inferior pulmonary artery growth at pre-stage II catheterization. A lower body surface area, greater ventricular end-diastolic pressure, and lower superior vena cava saturation were associated with worse 12-month transplant-free survival.

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BACKGROUND: A modification to the Norwood procedure involving a right ventricle-to-pulmonary artery (RV-PA) shunt may improve early postoperative outcomes. Concerns remain about the effect of the right ventriculotomy required with this shunt on long-term ventricular function. METHODS: Between January 2000 and April 2005, 76 patients underwent the Norwood procedure, 35 with a modified Blalock-Taussig shunt (mBTS) and 41 with a RV-PA shunt. Patients were monitored until death or September 1, 2009, with an average follow-up of 6.8 years. Cardiac catheterization, echocardiograms, perioperative Fontan courses, and need for cardiac transplantation were compared between groups. RESULTS: Cumulative survival was 63% (22 of 35) in the mBTS group vs 78% (32 of 41) in the RV-PA group (p = 0.14). Pre-Fontan echocardiography revealed poorer ventricular function in RV-PA patients (p = 0.03). Cardiac transplantation was required in 6 of 32 (19%) patients with a prior RV-PA shunt vs 1 of 23 (4%) in the mBTS group (p = 0.06). This results in an almost identical cumulative transplant-free survival between groups; 60% (21 of 35) in the mBTS group and 63% (26 of 41) in the RV-PA group (p = 0.95). CONCLUSIONS: Neither shunt offers a clear survival advantage through an average follow-up of 6.8 years. The RV-PA shunt results in impaired late ventricular function that may result in an increased need for cardiac transplantation.

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Three-dimensional (3D) transesophageal echocardiography (TEE) has numerous potential applications in the care of patients with congenital heart disease (CHD). However, there were few data examining its utility in this setting. The aim was to describe the initial experience and feasibility of this modality at a tertiary CHD center. Twenty-seven 3D-TEE studies using the x7-2t live 3D matrix TEE transducer with an iE33 echocardiographic scanner (Philips Medical Systems, Bothell, Washington) were attempted. The utility of this method was examined in the 3 settings of interventional catheterizations (n = 16), intraoperative studies (n = 4), and diagnostic studies (n = 7). The probe was successfully inserted in 26 of 27 patients (weight 22.6 to 110 kg). In conclusion, the current matrix-array 3D-TEE probe was found to have a wide variety of clinical applications in a CHD center.

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BACKGROUND: Traditional palliation of infants with biventricular hearts and inadequate pulmonary blood flow is a modified Blalock-Taussig shunt. The aim of this report is to assess the results of an alternative, right ventricle-to-pulmonary artery (RV-PA) shunt. METHODS: Between August 2004 and July 2007, 10 infants with biventricular hearts and inadequate pulmonary blood flow underwent palliation with an RV-PA shunt. Median age was 9 days (range, 4 to 86), weight was 3.0 kg (1.7 to 4.5), and 4 of 10 patients weighed less than 2.5 kg. Shunts were nonvalved Gore-Tex (W.L. Gore Assoc, Flagstaff, AZ), and size was 6 mm (n = 5) or 5 mm (n = 5). RESULTS: There were no operative deaths. Median oxygen saturation at hospital discharge was 95% (87 to 98). In 2 patients the shunt was partially narrowed with a metal clip; they underwent successful balloon dilation 6 months after shunt placement. Eight patients have undergone two-ventricle repair 6 to 17 months after shunt placement. At the time of complete repair, oxygen saturation was 86 +/- 1% and weight was 7.7 +/- 1.7 kg. Repairs included a valved RV-to-PA conduit, 14 to 16 mm in diameter. There was one interstage death. CONCLUSIONS: The RV-PA shunt provides successful palliation in infants with biventricular heart disease and inadequate pulmonary blood flow. It can be used in low birth weight infants and allows significant growth with protection of oxygen saturation prior to complete repair. Partial clipping of the shunt with subsequent balloon dilation is an option to prolong palliation. These results compare favorably with those of a modified Blalock-Taussig shunt or single stage complete repair.

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