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Sinus node dysfunction is a common problem and adversely impacts patients who have undergone the Fontan operation. In Fontan patients with an adequate junctional escape rhythm, the benefit of atrial pacing to restore atrioventricular synchrony remains unclear. Data were collected retrospectively on all Fontan patients with junctional rhythm who underwent atrial pacing during cardiac catheterization. Hemodynamics were obtained at baseline and after atrial pacing for 5–10 min. Seven patients, mean age 10 years (3–21) were studied. The type of Fontan was extracardiac in 6 and lateral tunnel in one. Patients were paced at 10 bpm faster than their junctional rate. With pacing, there was a significant decrease in left atrial pressure from (mean ± SEM) 8.8 ± 2.6 to 5.5 ± 2.9 mmHg (p = 0.02), a significant increase in cardiac index from 2.7 ± 0.8 to 3.5 ± 1 L/min/m2 (p = 0.01) and pulmonary blood flow from 2.1 ± 0.6 to 2.7 ± 0.7 L/min/m2 (p = 0.001), and no significant change in pulmonary artery pressure, from 13.4 ± 2.8 to 12.4 mmHg ± 3.6 (p = 0.06) or pulmonary vascular resistance from 2.1 ± 0.86 to 3.25 ± 1.9 WU × M2 (p = 0.1). In Fontan patients with junctional rhythm, atrial pacing decreased the left atrial pressure, increased cardiac output and did not significantly change the pulmonary artery pressure. Our study supports further investigation into the utility of prophylactic atrial pacemaker implantation in Fontan patients with significant durations of JR on ambulatory monitoring.

Background: Pulmonary hypertension is a rare disease that can have many long-term consequences, including death. Cardiac catheterization is the gold standard for measuring right ventricular systolic pressures (RVSP), but is invasive and has potentially deadly complications. Non-invasive echocardiographic parameters used to identify and monitor pulmonary hypertension only crudely approximate RVSP. The aim of this study was to create a quantifiable measure of RVSP using septal positioning that is easy to perform, reproducible with low inter-reader variability, and can accurately …

Acute Hemodynamic Effects of Pacing in Patients With Fontan Physiology: A Prospective StudyBrent J. Barber, Anjan S. Batra, Grant H. Burch, Irving Shen, Ross M. Ungerleider, John W. Brown, Mark W. ...

Background Carvedilol is a medication with both β-receptor and α-receptor blocking properties that has been approved for the treatment of heart failure in adults. Little is known about its safety, efficacy, pharmacokinetics, and dosing profile in children. Methods The primary objective of this study is to evaluate the efficacy of carvedilol administered twice daily for 8 months in terms of its effect compared with placebo on a composite measure of clinical outcomes in children with symptomatic systemic ventricular systolic dysfunction and heart failure. The secondary objectives are to determine the effect of carvedilol on individual components of a composite of clinical outcomes (hospitalizations for worsening heart failure, all-cause mortality and cardiovascular hospitalizations, all cause mortality, heart failure symptoms, and patient and physician global assessment); determine the effect of carvedilol on echocardiographic indices of ventricular function and remodeling; characterize the pharmacokinetics of carvedilol in pediatric patients with heart failure; characterize the effects carvedilol on neurohormonal systems; and provide data for the selection of an optimal titration schedule and daily dose of carvedilol in children with heart failure. This study will enroll 150 children between birth and 17 years of age with chronic symptomatic heart failure caused by systemic ventricular systolic dysfunction. Conclusion This study will determine whether carvedilol improves symptoms in children with heart failure as a result of systemic ventricular systolic dysfunction. The study also will provide information on echocardiographic changes of ventricular performance and neurohormonal levels in children with heart failure before and after treatment with carvedilol, in addition to pharmacokinetics of carvedilol in children. (Am Heart J 2002;144:383-9.)

Platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) have been implicated in myointimal proliferative arteriopathy, a lesion seen in monocrotaline-induced pulmonary hypertension (MIPH). The purpose of this study was to examine the expression of PDGF and bFGF in the lungs of rats given monocrotaline and to examine the effects of amrinone on the hearts and lungs of these rats. Twenty-four 26-day-old rats were randomized to receive either monocrotaline (approximately 3.6 mg/kg/d) or no monocrotaline and concomitantly to receive either amrinone (100 mg/kg/d) or no amrinone for 21 days. Lungs were examined for immunohistochemical evidence of PDGF and bFGF, and hearts were examined for effects of pulmonary hypertension and amrinone. Immunohistochemical staining of lungs showed no evidence of PDGF except in bronchioles. bFGF staining was similar between groups (no monocrotaline 25%, monocrotaline 27%, monocrotaline and amrinone 22%), and the staining was confined to the arterial walls. Rats given monocrotaline showed significantly greater right ventricular (RV) weight (0.13 +/- 0.02 g versus 0.23 +/- 0.04 g [mean +/- SD], P < 0.001), right ventricular/left ventricular (RV/LV) weight ratio (0.29 +/- 0.06 versus 0.59 +/- 0.1, P < 0.001), and lung/body weight ratio (0.006 +/- 0.001 versus 0.01 +/- 0.003, P < 0.05) than controls. Rats given monocrotaline and amrinone were not significantly different from rats given only monocrotaline with regard to RV weight, RV/LV weight ratio, or lung/body weight ratio. We conclude that the vasculopathy seen in MIPH is not associated with the presence of PDGF or bFGF, suggesting that other growth factors may mediate this process. The course of MIPH is not altered by amrinone.

ObjectivesThis study sought to develop a method to adjust for case mix complexity in catheterization for congenital heart disease to allow equitable comparisons of adverse event (AE) rates.BackgroundThe C3PO (Congenital Cardiac Catheterization Project on Outcomes) has been prospectively collecting data using a Web-based data entry tool on all catheterization cases at 8 pediatric institutions since 2007.MethodsA multivariable logistic regression model with high-severity AE outcome was built using a random sample of 75% of cases in the multicenter cohort; the models were assessed in the remaining 25%. Model discrimination was assessed by the C-statistic and calibration with Hosmer-Lemeshow test. The final models were used to calculate standardized AE ratios.ResultsBetween August 2007 and December 2009, 9,362 cases were recorded at 8 pediatric institutions of which high-severity events occurred in 454 cases (5%). Assessment of empirical data yielded 4 independent indicators of hemodynamic vulnerability. Final multivariable models included procedure type risk category (odds ratios [OR] for category: 2 = 2.4, 3 = 4.9, 4 = 7.6, all p < 0.001), number of hemodynamic indicators (OR for 1 indicator = 1.5, ≥2 = 1.8, p = 0.005 and p < 0.001), and age

Objective: Aortic valvotomy is widely used for the treatment of congenital aortic stenosis in children. We sought to evaluate whether the predominant post-valvotomy physiology, aortic insufficiency (AI) or aortic stenosis (AS) independently affected patient outcome. Methods: From 1972‐2002, 57 children with congenital aortic stenosis underwent valvotomy. We divided age-matched patients with residual lesions based on their predominant pathology into three groups: Group I (nZ14), patients with moderate AI; Group II (nZ14), patients with moderate AS, and Group III (nZ14), patients with combined AI and AS. Fifteen patients with severe AI or mild residual lesions following valvotomy were excluded from analysis. Results: mean freedom from aortic valve replacement (AVR) was 11.2G1.7 years in Group I and 21.5G3.9 years in Group II, PZ0.05. AVR was required in 11 patients (79%) in Group I vs. only 5 (36%) in Group II, PZ0.05. Group III was intermediate, with 9 (64%) requiring AVR. At the time of AVR, patients with aortic stenosis had significantly higher fractional shortening % than those with insufficiency or combined lesions, (Group 1: 38.2G7.9 vs. Group II: 46.3G5.5 vs. Group III: 39.2G3.7, PZ0.007). Patients in Group II also had less severely dilated ventricles (mm) than those in the other groups, (Group 1: 50.2G12.5 vs. Group II: 39.5G8.3 vs. Group III: 49.0G8.1, PZ0.030). Conclusions: patients with predominant AI following valvotomy are more likely to need AVR sooner than those with residual stenosis without AI. Therefore, cautious use of repeat valvotomy using maneuvers to avoid AI (small balloons), may prolong freedom from aortic valve replacement in those patients with significant residual AS. q 2004 Elsevier B.V. All rights reserved.

Objective: Placement of oversized pulmonary ventricle‐pulmonary artery conduits is routinely performed to decrease conduit failure in children. However, this practice has recently been challenged as somatic outgrowth may not be the main determinant of allograft failure in children. Our objective was to determine whether placement of oversized homografts for extracardiac pulmonary ventricle (PV) outflow tract reconstruction improves longevity in young children. Methods: We reviewed 102 consecutive PV‐PA conduits inserted in 70 patients less than 18 years between 1984 and 2003. Conduits placed in an anatomic position (nZ23) as part of a Ross operation, were excluded. Conduits were initially stratified into two age groups: Group 1, those placed in patients %10 years, and Group 2, those placed in patients O10 years. Normalization of conduit size to patient’s body surface area at the time of insertion (z-value) was then performed to divide the conduits into oversized (O/S) and non-oversized (NO/S) groups. Determinants of conduit failure and allograft longevity were then compared between groups. Results: Seventy-nine extracardiac conduits were placed, and 57 of these were in patients under 10 years of age. The majority had a diagnosis of tetralogy of Fallot (nZ38), truncus arteriosus (nZ19), pulmonary atresia with ventricular septal defect (nZ12), or D-TGA with pulmonary stenosis and ventricular septal defect (nZ7). Thirty-seven conduits were oversized (O/S) based on z-value, and 42 were non-oversized (NO/S), and the mean age at initial homograft placement was 7.0G7.5 years. Overall, oversizing conferred no significant advantage with respect to actuarial freedom from homograft replacement at 1, 5, or 10 years (96, 79, and 21%, O/S vs 93, 60, and 24%, NO/S), PZ0.44. Oversizing was more frequent in Group 1 than Group 2 (53 vs 32%), and conduit failure was also more frequent with 49% requiring reoperation during the study period vs 38% in Group 2. In the subset of patients %10 years, both homograft explantation rate (50% O/S vs 48% NO/S) and median interval to conduit failure were similar between the O/S and NO/S patients (7.1 vs 4.8 years), PZ0.340. Risk factors for conduit failure identified in multivariable regression analysis included the presence of pulmonary artery branch stenosis, lack of previous definitive repair, a diagnosis of pulmonary atresia, the need for percutaneous intervention. Conclusions: There is no significant benefit to placement of an oversized PV‐PA homograft in this series of patients from a single institution. Even in young patients with rapid somatic growth, normalizing extracardiac allografts to BSA provides excellent conduit longevity and outcomes. q 2005 Elsevier B.V. All rights reserved.

We describe a 5-year-old boy with Fontan physiology and a ventricular pacemaker who developed severe plastic bronchitis. Evaluation by cardiac catheterization revealed profoundly altered hemodynamics, which improved with atrial pacing. Following implantation of an atrial pacemaker, which restored atrioventricular (A-V) synchrony, the patient’s hemodynamics greatly improved and his plastic bronchitis resolved.

Balloon angioplasty or early surgical correction is recommended once coarctation of the aorta has been diagnosed. Medical management is not a long-term option. The rate of restenosis is higher in infants and children than in adults, but the incidence of residual or late hypertension increases with age at initial intervention. Current angioplasty and stent placement techniques have reduced the rate of aneurysm formation and expanded the types of complex anatomic configurations amenable to nonsurgical intervention. Patients require long-term follow-up for restenosis and late or residual hypertension. Coarctation treatment is straightforward in patients with simple isolated coarctation. In neonates with associated lesions and diffuse arch hypoplasia, aggressive (albeit higher-risk) arch-enlargement procedures can be done at the time of open-heart correction of intracardiac defects. Changes in aortic compliance, vascular reactivity, and vascular homeostasis mechanisms in patients who have late surgery are associated with a higher incidence of residual hypertension.

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