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OBJECTIVES: When extracorporeal membrane oxygenation (ECMO) is used in the setting of severe myocardial dysfunction, left ventricular end-diastolic and left atrial pressure can rise to extremely high levels. Decompression of the left atrium in this setting is essential for resolution of pulmonary edema and recovery of left ventricular function. We sought to evaluate whether adequate left atrial decompression can be achieved via percutaneous placement of a transseptal left atrial drain incorporated in the ECMO venous circuit. DESIGN: Retrospective case series. SETTING: Tertiary care center pediatric intensive care unit and cardiac catheterization laboratory. PATIENTS: Seven patients (age 8 months to 28 yrs) with cardiac failure on venoarterial ECMO with left atrial hypertension. INTERVENTIONS: All patients underwent left atrial decompression with transseptal puncture and placement of a drain (8- to 15-Fr) incorporated into the ECMO venous circuit. Catheterization and ECMO records and echocardiograms were reviewed, as were the clinical course and outcome for each patient. MEASUREMENTS AND MAIN RESULTS: The median time from ECMO cannulation to left atrial decompression was 11 hrs. Average initial left atrial pressure was 31 mm Hg. Successful drain placement was achieved in seven patients with no major procedural complications. Echocardiographic improvement in left atrial dilation was achieved in five patients (71%). Inability to decompress the left atrium was fatal in two patients. Four patients were decannulated (57%), and three survived to hospital discharge (43%). Larger sheath size and higher flow rate correlated with a greater likelihood of success. CONCLUSIONS: Adequate decompression of the left atrium can be achieved by transseptal placement of a left atrial drain incorporated into the ECMO circuit. This technique represents a reasonable alternative to blade or balloon atrial septostomy for patients requiring left atrial decompression. [ABSTRACT FROM AUTHOR]

Patients with a single ventricle heart who had Fontan palliation (S/P Fontan) are at increased risk for acquired morbidity. Insulin resistance (IR) is a predictor of cardiac morbidity and mortality. A single-center, cross-sectional study using S/P Fontan and controls was designed to assess IR S/P Fontan. Group comparisons were made in IR via the Quantitative Insulin Index (QUICKI) and the natural log-transformed homeostasis model assessment, ln (HOMA-IR), without/with adjusting for age. A total of 89 patients (59 Fontan and 30 controls) were included. Fontan patients showed a significant decrease in QUICKI (0.34 ± 0.03 vs 0.37 ± 0.02) and an elevation of ln (HOMA-IR) (0.82 ± 0.62 vs 0.24 ± 0.44) compared to controls (both p < 0.0001); this remained significant even adjusting for age. With older age, there was a significant, progressive decrease in QUICKI (p = 0.01) and an increase in ln (HOMA-IR) (p = 0.02) S/P Fontan. Analysis excluding Fontan patients with obesity still showed a significant reduction of QUICKI and an elevation of ln (HOMA-IR) in Fontan patients compared to controls when adjusting for age (both p < 0.05). Using QUICKI, IR was present in 41 (69.5%) Fontan patients vs. 3 (10%) controls (p < 0.0001) and using HOMA-IR, IR was present in 32 (54.2%) vs 5 (16.7%) controls (p = 0.001). Fontan patients had significantly more IR compared to controls and the prevalence of IR increases with age. Since IR is known to correlate with long-term morbidity and mortality and can be ameliorated by therapies, we believe it is critical that IR be identified as early as possible in Fontan patients., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Prolonged pleural drainage is a common complication in patients after Fontan palliation and is associated with short- and long- term morbidities. Among many potential etiologies, prolonged drainage has an inflammatory component, but there are no descriptions of cytokines in Fontan pleural drainage to date. This study aimed to examine the inflammatory make-up of Fontan pleural drainage. This prospective age-range-matched cohort study recruited 25 patients undergoing Fontan procedure and 15 bi-ventricular patients undergoing cardiopulmonary bypass (CPB). Chest tube samples were taken on postoperative day (POD) 1-4, 7, and 10. Cytokines were measured using Bio-Plex Assays. Univariate comparisons were made in patient characteristics and cytokine levels. Median age was 3.7 y (IQR 2.8-3.9) for controls and 2.5 y (IQR 2.1-2.9) in Fontan patients (p = 0.02). Median drainage duration and daily volume was higher in Fontan patients (both p < 0.001). Inflammatory cytokines (IL-17A, IFN-y, MIP-1β, and TNF-α) were higher in Fontan patients than controls (all p < 0.02). There was an increase in pro-inflammatory cytokines (IL-8, MIP-1β, and TNF-α) from POD1 to the last chest tube day (LCD) in Fontan patients (all p < 0.0001) and a decrease in the anti-inflammatory cytokine IL-10 (p = 0.001). There was no difference in cytokine concentration from POD1 to LCD among controls. There was a significant association with the cytokine concentration of TNF-α on POD1 and duration of chest tube drainage (p < 0.05). Inflammatory cytokine levels in the pleural fluid of Fontan patients are higher compared to bi-ventricular controls and rise over time where controls do not. This suggests ongoing localized inflammation that is not a result of CPB alone and may be an important contributor to pleural drainage in patients after the Fontan procedure.

Epicardial fat produces multiple proinflammatory cytokines and is associated with adverse cardiovascular events. Inflammation and resultant endothelial dysfunction may play a role in progressive myocardial dysfunction among adults with single ventricle physiology after Fontan palliation, but the potential impact of increased epicardial fat volume (EFV) has not been studied. This study sought to determine if there is greater EFV in Fontan patients compared with a group of repaired tetralogy of Fallot (rTOF) patients. We retrospectively measured EFV manually on cardiac magnetic resonance imaging in Fontan patients, ≥15 years, and 1:1 age, sex, and body mass index-matched patients with rTOF. EFV was indexed to body surface area. A random subset of studies was re-measured to assess intra- and interobserver reliability. Fontan patients (n = 63, median age 21.6 years, 51% male, mean body mass index 24.2 ± 5.6 kg/m 2 ) had a larger indexed EFV compared with matched rTOF patients (75.3 ± 29.2 ml/m 2 vs 60.0 ± 19.9 ml/m 2 , p = 0.001). In Fontan patients, indexed EFV was inversely correlated with ventricular ejection fraction (r = -0.26, p = 0.04) and cardiac index (r = -0.33, p = 0.01). Intra- and interobserver reliabilities of the indexed EFV measurements in both groups were excellent (intraclass correlation coefficient ranges from 0.93 to 0.97). In conclusion, indexed EFV is higher in Fontan patients compared with patients with rTOF and is associated with lower ventricular ejection fraction and cardiac index. Increased EFV could play a role in the failing Fontan circulation, but longitudinal studies are necessary to establish any causative role., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Although surgical patch arterioplasty is the conventional therapy for branch pulmonary artery (PA) stenosis, limited data exist on long-term outcomes. We examined the incidence of and risk factors for reintervention after surgical arterioplasty for branch PA stenosis in biventricular congenital heart disease., Methods: This retrospective cohort study included patients with 2-ventricle physiology who underwent patch arterioplasty for PA stenosis at a single high-volume congenital heart center during a 10-year period. Freedom from surgical or percutaneous reintervention for recurrent PA stenosis was evaluated. Univariate and multivariable Cox regression analyses were performed to determine risk factors for reintervention., Results: Among 135 patients, the median age at patch arterioplasty was 0.9 years. Survival to hospital discharge (or 30 days postoperatively) was 96%. During a median follow-up period of 4.0 years, reintervention for PA stenosis occurred in 38 of 115 patients (33%) at a median time to reintervention of 1.4 years. The overall 10-year reintervention rate was 54%. In univariate analysis, age less than 30 days at initial arterioplasty, congenital PA stenosis (vs acquired), and bilateral PA stenosis (vs unilateral) were significantly associated with reintervention. In multivariable analysis, neonatal age (adjusted hazard ratio, 3.6; p = 0.002) and bilateral PA stenosis (adjusted hazard ratio, 2.8; p = 0.005) remained independently associated with reintervention., Conclusions: Long-term reintervention for recurrent PA stenosis after patch arterioplasty is common. Patients with bilateral PA stenosis or age younger than 30 days at the time of the index pulmonary arterioplasty are at higher risk for reintervention. These patients may benefit from frequent monitoring or novel approaches to repair., (Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: We sought to identify a time during cardiac ejection when the instantaneous pressure gradient (IPG) correlated best, and near unity, with peak-to-peak systolic ejection gradient (PPSG) in patients with congenital aortic stenosis. Noninvasive echocardiographic measurement of IPG has limited correlation with cardiac catheterization measured PPSG across the spectrum of disease severity of congenital aortic stenosis. A major contributor is the observation that these measures are inherently different with a variable relationship dependent on the degree of stenosis., Design: Hemodynamic data from cardiac catheterizations utilizing simultaneous pressure measurements from the left ventricle (LV) and ascending aorta (AAo) in patients with congenital valvar aortic stenosis was retrospectively reviewed over the past 5 years. The cardiac cycle was standardized for all patients using the percentage of total LV ejection time (ET). Instantaneous gradient at 5% intervals of ET were compared to PPSG using linear regression and Bland-Altman analysis., Results: A total of 22 patients underwent catheterization at a median age of 13.7 years (interquartile range [IQR] 10.3-18.0) and median weight of 51.1 kg (IQR 34.2-71.6). The PPSG was 46.5 ± 12.6 mm Hg (mean ± SD) and correlated suboptimally with the maximum and mean IPG. The midsystolic IPG (occurring at 50% of ET) had the strongest correlation with the PPSG ( PPSG = 0.97(IPG50%)-1.12, R 2  = 0.88), while the IPG at 55% of ET was closest to unity ( PPSG = 0.997(IPG55%)-1.17, R 2  = 0.87)., Conclusions: The commonly measured maximum and mean IPG are suboptimal estimates of the PPSG in congenital aortic stenosis. Using catheter-based data, IPG at 50%-55% of ejection correlates well with PPSG. This may allow for a more accurate estimation of PPSG via noninvasive assessment of IPG., (© 2017 Wiley Periodicals, Inc.)

Objectives: To describe our 20-year experience with intraoperative pulmonary artery (PA) stent placement and evaluate long-term patient outcomes, specifically the need and risk factors for reintervention., Background: Intraoperative PA stent placement is an alternative to surgical patch arterioplasty and percutaneous angioplasty or stent placement to treat branch PA stenosis., Methods: We performed a retrospective review of all intraoperative PA stents placed at our institution from 1994-2013. Patient and stent characteristics and outcome data were collected. Risk factors associated with reintervention were identified using univariate cox regression analysis., Results: Eighty-one PA stents were placed in 68 patients. The procedural complication rate was 4.4%. During a median follow-up period of 6 years (interquartile range [IQR] 0.9-12.7), 30 patients (44%) underwent reintervention on the stented PA with a median time to first reintervention of 2.6 years (IQR 0.7-4.4 years). The first reintervention was surgical in 30% and catheter-based in 70%. Risk factors for reintervention included age < 18 months (Hazard ratio [HR] 2.97, P = 0.005) and body surface area < 0.47 m 2 (HR 3.20, P = 0.003) at the time of stent implantation, and the presence of multiple aortopulmonary collaterals in patients with tetralogy of Fallot (HR 4.61, P = 0.003)., Conclusions: Intraoperative PA stent implantation is a safe and effective alternative to percutaneous stent implantation and offers several advantages, including the ability to implant adult-size stents in small patients while avoiding injury to peripheral vessels, to position stents to facilitate future percutaneous stent redilation, and to access the PAs directly, which eliminates radiation exposure. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Aim: The intent of the present study was to evaluate changes in ventricular function with percutaneous closure of atrial septal defect (ASD), as it is associated with alterations in ventricular loading and function. Transcatheter occlusion of ASD imparts acute changes in volume loading of the left ventricle (LV) that obscures measurement of ventricular function by load-dependent indices. To differentiate between changes in ventricular loading and function, load-independent indices of ventricular function must be utilized., Methods: During transcatheter occlusion of ASD, subjects underwent measurement of LV pressure and volume by the conductance catheter method. Load-dependent indices of ventricular function included: systolic and diastolic pressures, +dP/dtmax , and -dP/dtmax . Load-independent indices included: elastance and tau, the preload-independent time constant ofisovolumic relaxation. To obtain elastance, afterload was augmented by phenylephrine bolus pre- and post-device occlusion., Results: In total, 29 patients (age 2-79 years) underwent ASD device occlusion (device size 12-38 mm, median 28 mm). Load-dependent indices were obtained in all, and satisfactory pressure-volume loops in 11. At baseline, LV end-diastolic pressure was 5-23 mmHg (13 ± 5 mmHg) and tau was 31 ± 6 ms. Postclosure of the ASD, LV systolic and diastolic pressures rose by 10 ± 11 mmHg and 5 ± 3 mmHg, respectively (P < 0.05), and +dP/dtmax rose from 1,288 ± 313 mmHg/sec to 1,415 ± 465 mmHg/sec (P < 0.05), but -dP/dtmax was unchanged. Elastance significantly improved (9.4 ± 8.3 mmHg/mL vs. 13.0 ± 7.3 mmHg/mL, P < 0.05) and tau was unchanged., Conclusions: Transcatheter occlusion of ASD is associated with acute improvement in load-independent indices of systolic function in this cohort, without significant worsening of the preload-independent index of diastolic function., (© 2014, Wiley Periodicals, Inc.)

Objective:   To evaluate the impact of antioxidant therapy on functional health status in Fontan-palliated patients. Design.  Prospective, randomized, double-blind, placebo-controlled trial., Patients:   Fifty-three generally asymptomatic Fontan patients., Interventions:   Patients were randomized to receive either high-dose ascorbic acid (vitamin C) or placebo for 4 weeks., Outcome Measures:   Peripheral vascular function, as measured with endothelium-dependent digital pulse amplitude testing (EndoPAT), and exercise capacity were assessed before and after study drug treatment. Primary outcome measures included the EndoPAT index and peripheral arterial tonometry (PAT) ratio, both validated markers of vascular function. Secondary outcome measures included peak oxygen consumption and work., Results:   Twenty-three vitamin C- and 21 placebo-assigned subjects completed the protocol (83%). Median age and time from Fontan completion were 15 (interquartile range [IQR] 11.7-18.2) and 11.9 years (IQR 9.0-15.7), respectively. Right ventricular morphology was dominant in 30 (57%). Outcome measures were similar between groups at baseline. Among all subjects, vitamin C therapy was not associated with a statistical improvement in either primary or secondary outcome measures. In subjects with abnormal vascular function at baseline, compared with placebo, vitamin C therapy more frequently resulted in normalization of the EndoPAT index (45% vs. 17%) and PAT ratio (38% vs. 13%)., Conclusions:   Short-term therapy with vitamin C does not alter endothelial function or exercise capacity in an asymptomatic Fontan population overall. Vitamin C may provide benefit to a subset of Fontan patients with abnormal vascular function., (© 2011 Wiley Periodicals, Inc.)

Fetal cardiac intervention for critical aortic stenosis (AS) with evolving hypoplastic left heart syndrome is performed in an attempt to maintain a biventricular circulation postnatally. The procedure has been hindered by technical challenges and poor candidate selection. We report here the novel use of a pressure guidewire during aortic valvuloplasty in a fetus at 21 weeks' gestation with critical AS and evolving hypoplastic left heart syndrome. Use of a pressure guidewire during fetal cardiac intervention offers several potential advantages over existing protocols. This technique augments fetal ultrasound as it relates to operator awareness of catheter and wire position (with continuous monitoring of pressure waveforms), improves on intraprocedural fetal hemodynamic monitoring and responsiveness to resuscitation, and provides a rich new data set of invasive fetal hemodynamics. This data set offers tremendous potential with regards to improving candidate selection and postintervention prognostication. In addition, we provide the first, to our knowledge, characterization of intracardiac pressures in a human fetus with congenital heart disease. Given the realized and potential benefits associated with this technique, use of a pressure guidewire may become standard of care for all fetal cardiac interventions.

Fontan patients have a reduced exercise capacity, primarily owing to limitations in the ability to augment pulmonary blood flow and stroke volume. To date, the mechanism of peak exercise pulmonary blood flow restriction has not been elucidated. We performed a single-center, prospective, crossover trial of supine and upright exercise in Fontan patients and healthy controls to determine the mechanisms of exercise limitation in the Fontan-palliated patient. A total of 29 Fontan patients and 16 control subjects completed the protocol. The duration of exercise, percentage of predicted peak oxygen consumption (VO(2)) and peak work were reduced in the Fontan group, regardless of posture (p < or = 0.03). The percentage of predicted oxygen pulse, a surrogate for pulmonary stroke volume, was not increased with supine posture in the Fontan cohort (upright, 82.3 + or - 18.8% vs supine, 82.4 + or - 19.7%; p = 0.6). In both groups, the percentage of predicted peak VO(2) was lower with supine exercise than with upright exercise (p < or =0.002). Diastolic dysfunction was present in 57% of the Fontan patients and was associated with a reduced percentage of predicted peak VO(2) (p = 0.04) and supine peak work (p = 0.008). Six Fontan patients who underwent supine exercise with indwelling catheters failed to demonstrate the expected decrease in pulmonary vascular resistance characteristically seen with peak exercise (at rest, 2.8 + or - 0.7 mm Hg/L/min/m(2) vs at peak, 2.8 + or - 0.9 mm Hg/L/min/m(2); p = 0.9). In conclusion, supine exercise in Fontan patients does not result in an increased VO(2) or oxygen pulse, suggesting that inadequate venous return might not be the primary limitation of exercise capacity in this population. Diastolic dysfunction and relatively excessive peak exercise pulmonary vascular resistance might be more important factors in Fontan exercise limitation., (Copyright 2010 Elsevier Inc. All rights reserved.)

The role of increased sympathetic nervous system (SNS) activity in the pathogenesis of obesity hypertension and insulin resistance is controversial. Eight dogs were instrumented and fed a high-fat diet (HFD) for 6 weeks. Dogs were evaluated for changes in weight, blood pressure, insulin resistance, and norepinephrine (NE) kinetics using a two-compartment model. The HFD resulted in weight gain, hypertension, and insulin resistance. During the 6 weeks of the HFD, although plasma NE concentration trended toward increasing (P=.09), SNS, assessed by NE kinetic studies, significantly increased (P=.009). Within 1 week of starting the HFD, NE release into the extravascular compartment (NE(2)) increased from 3.44+/-0.59 microg/mL to 4.87+/-0.80 microg/mL (P<.01) and this increase was maintained over the next 5 weeks of the HFD (NE(2) at week 6 was 4.66+/-0.97 microg/mL). In addition to the increased NE(2) there was also a significant increase in NE clearance (P=.04). There were significant correlations between the increase in NE(2) and both the development of insulin resistance and hypertension. This study supports the hypothesis that activation of the SNS plays a pivotal role in the metabolic and hemodynamic changes that occur with weight gain induced by HFD.

Background: During the past 15 years, closure of a secundum atrial septal defect (ASD) has moved from a surgical to a percutaneous transcatheter approach. Few long-term studies of the efficacy and safety of closure of an ASD by an Amplatzer septal occluder (ASO) exist., Methods: To examine the long-term results of secundum ASD closure using the ASO, data on 94 patients who underwent secundum ASD closure with the ASO between 1998 and 2002 were available and reviewed. Data regarding residual shunt, chest pain, palpitations, arrhythmias, headaches, transient ischemic attacks, cerebrovascular accidents, and mortality were collected., Results: Seven (7.4%) subjects had residual shunts immediately following ASO placement. During follow-up, 4 residual shunts closed for a complete closure rate of 97%. Eighteen (19%) patients reported chest pain during the follow-up period. Twenty-three patients (24%) reported palpitations during the follow up period, 7 were documented arrhythmias, including supraventricular tachycardia, atrial fibrillation, and premature ventricular beats. Migraine headaches were new-onset in 4 patients. Migraine cessation occurred in 2 patients after secundum ASD closure. One child died from a cerebral vascular event 18 months following device placement. Only 1 patient developed mild aortic insufficiency., Conclusion: These data indicate that for up to 120 months of patient follow-up, the ASO continues to be a safe device. Residual shunts and arrhythmias have low incidence post-ASO placement. Given the mortality in one high-risk patient, further investigation into anti-platelet therapy after device placement is warranted.

A 4-year-old female with hypoplastic left heart syndrome and Fontan palliation presented with severe neurologic impairment from thrombosis of the superior vena cava (SVC). She underwent successful SVC thrombectomy with the X-SIZER Thrombectomy Catheter System, followed by balloon angioplasty. She demonstrated rapid improvement in her neurologic deficits after the procedure. This represents the first published use of the X-SIZER in a child and its first published use for SVC thrombectomy., (Copyright (c) 2006 Wiley-Liss, Inc.)

Infants with hypoplastic left heart syndrome (HLHS) and restrictive or intact atrial septum (rAS) present with cyanosis, pulmonary edema, and are critically ill. A previous report from our institution on emergent Norwood for HLHS with rAS showed 10% survival. We hypothesized that transcatheter left atrial (LA) decompression in HLHS with rAS would safely and effectively relieve LA hypertension, improve oxygenation, and improve Norwood survival. Between 1996 and 2004, 30 patients with HLHS and rAS underwent cardiac catheterization for pre-Norwood intervention. Twenty-eight atrial septostomies were performed: 23 static balloon dilations, 4 Rashkind septostomies, and 1 intra-atrial stent. Two procedures were aborted due to perforation (n = 1) or inability to enter the LA (n = 1). Eight total patients required surgical septectomy, for a failure rate of 27%. There were no catheter-related mortalities, although two patients died within 36 hr of the procedure after surgical septectomy. Major complications occurred in three patients (10%)--atrial perforations requiring intervention. Mean atrial septal defect gradient fell from 16.7 +/- 4.9 to 6.3 +/- 3.4 mm Hg (P < 0.001; n = 18). Mean LA pressure dropped from 21.8 +/- 5.5 to 13.1 +/- 6.5 mm Hg (P < 0.001; n = 16). Mean PaO(2) rose from 29.5 +/- 9.1 to 36.5 +/- 5.1 torr (P < 0.001; n = 23). Seventeen of 30 patients (57%) survived to discharge from Norwood. Thirteen have undergone hemi-Fontan and nine Fontan. Sixteen of 22 successful decompressions (73%) survived to discharge. Transcatheter decompression of the LA for patients with HLHS and rAS can be performed safely, reduces the transatrial gradient, and improves oxygenation. Catheter intervention improves survival compared to historical controls undergoing emergent Norwood.

Background: The surgical repair of aortic coarctation in infants has evolved over time. This study evaluates our current approach utilizing extended end-to-end anastomosis without prosthetic material to enlarge all areas of aortic arch hypoplasia., Methods: The Michigan Congenital Heart Center database was reviewed for infants who underwent repair of isolated aortic coarctation from January 1, 1990, to January 1, 2000., Results: Eighty-three infants underwent surgical repair of isolated coarctation during this decade. Median age at repair was 21 days (range, 2 to 365). Repair was performed through thoracotomy in 72 patients. Because of severe transverse arch hypoplasia, the remaining 11 infants underwent median sternotomy with circulatory arrest. There were 2 deaths: 1 due to pulmonary hypertension in a patient with alveolar capillary dysplasia and 1 late death due to pneumonia in a patient with noncardiac anomalies. Neither patient had residual coarctation. Technique-related complications of bronchial compression, chylothorax, and vocal cord paralysis were noted in 4 patients. Follow-up data were available for 66 patients (80%) with mean follow-up duration of 4.5 years (SD +/- 3.1). Reintervention was required in 4 patients (6%). One underwent reoperation after 1 month, and 3 underwent balloon angioplasty within 7 months of initial repair. The remaining 61 patients are asymptomatic, on no antihypertensive medications, and have aortic arch gradients less than 15 mm Hg. One developed subaortic stenosis necessitating resection., Conclusions: Tailored surgical repair for aortic coarctation has a low rate (6%) of residual and recurrent coarctation even when performed in infants. Mortality and morbidity are low.

Development of aortopulmonary collaterals during the course of surgical palliation for single-ventricular anatomy has been linked to adverse outcomes following Fontan palliation. We investigated the hemodynamic significance of aortopulmonary collaterals during presurgical cardiac catheterization of patients with single-ventricle surgically palliated anatomy. Thermal indicator dilution studies were performed to determine degree of shunt. A total of 52 patients were studied and the data were analyzed. Measurements by thermal indicator dilution correlated significantly with qualitative angiographic grading of aortopulmonary collaterals. However, the hemodynamic significance of these aortopulmonary collaterals, as measured by thermal indicator dilution, did not correlate with postoperative outcome variables. This study demonstrated that thermal indicator dilution measurement holds promise for hemodynamically quantifying the significance of aortopulmonary shunts in surgically palliated single-ventricular patients. However, the degree of recirculation from aortopulmonary collaterals does not correlate with outcome after Fontan surgery in this patient cohort.

Echocardiographic indexes of left ventricular (LV) diastolic function were assessed in 18 patients before and after device closure of secundum atrial septal defects. The tissue Doppler early diastolic peak annular velocity (Ea) and color M-mode velocity of propagation (Vp), indexes of relaxation, seemed to be load independent and were not affected by the change in LV filling hemodynamics, whereas the mitral inflow peak E-wave velocity and E/Ea ratio were more load dependent, with a resultant increase after the closure of large atrial shunts.

Oral L-arginine therapy reverses endothelial dysfunction and attenuates high blood pressure in hypertensive cardiac transplant recipients. L-arginine corrects derangements in the vascular endothelial nitric oxide (NO)-dependent signaling pathway. Our data support the concept that cardiac transplant recipients use excess endogenous NO from L-arginine supplementation to buffer increased vascular oxidant stress.

In dogs fed a high-fat diet, we determined whether there was a direct relation between obesity-induced insulin resistance and obesity-induced hypertension. Thirty-six adult mongrel dogs were chronically instrumented and assigned to receive either a high-fat diet alone (n=7) or a high-fat diet combined with a low-sodium diet plus furosemide (n=6), prazosin plus atenolol (n=7), clonidine (n=10), or aspirin (n=6). Blood pressure, heart rate, and body weight were measured daily. Insulin resistance was assessed with a single-dose euglycemic hyperinsulinemic clamp (2 mU x kg(-1) x min(-1)) before and after 1, 3, and 6 weeks of the high-fat diet. The low-salt diet plus furosemide, prazosin plus atenolol, and clonidine treatments prevented the hypertension associated with feeding the dogs a high-fat diet. Only clonidine treatment totally prevented the development of insulin resistance, and high-dose aspirin, known to prevent insulin resistance by inhibition of the activity of IkappaB kinase-beta, decreased the degree of insulin resistance by almost 70%. However, aspirin had no effect on the development of hypertension. We conclude that obesity-induced hypertension and obesity-induced insulin resistance are not directly related. In addition, there is a suggestion that insulin resistance in this experimental model is mediated through the central and or peripheral alpha2-adrenoceptors, whereas hypertension is mediated through the alpha1- and or beta-adrenoceptors.

Purpose: Congenital aortic valve stenosis is a common problem in pediatric cardiology. The catheter peak to peak systolic gradient is the accepted standard used for prognosis and intervention, but noninvasive correlation in pediatric patients is frequently associated with underestimation or overestimation of this gradient. The purpose of this study was to compare different noninvasive measurements with simultaneous catheter gradients to identify which best predicts the catheter peak to peak gradient., Methods: Twenty-five simultaneous Doppler and catheter measurements of aortic stenosis gradient were performed in 14 children (all 14 before valvuloplasty and 11 after valvuloplasty). Noninvasive estimates of pressure gradient were compared with catheter measurements with linear regression and Bland-Altman analysis., Results: The Doppler peak instantaneous pressure gradient overestimated the catheter peak to peak gradient but correlated well with the catheter peak instantaneous gradient. The Doppler mean systolic gradient correlated well with the catheter peak to peak gradient at low gradients and underestimated higher catheter gradients but agreed well at all levels with the catheter mean gradient. The modification of a catheter-derived correlation equation produced good correlation with the catheter peak to peak gradient (slope, 1.14; intercept, -1.8; R, 0.92), as did the use of estimated pressure recovery (slope, 1.04; intercept, 5.0; R, 0.94), calculated from a defined fluid mechanic equation., Conclusion: The catheter peak to peak gradient can be accurately estimated noninvasively using estimated pressure recovery or correlation equations incorporating Doppler measurements.

During the past decade, there has been a surge of interest in childhood and adolescent hypertension. The current review summarizes work published during the past year in the following areas: prenatal and early postnatal causes of hypertension; new information on the genetics of childhood hypertension; the relation of obesity, insulin resistance, and diabetes to hypertension; the use of ambulatory blood pressure monitoring to evaluate childhood hypertension; and advances in drug therapy for children with hypertension. The information obtained during the past year has improved our understanding of the pathogenesis, diagnosis, and treatment of childhood hypertension.

The publications of 2000 and 2001 stress how interventional pediatric cardiology has moved from angioplasty to device placement. This review summarizes the important articles during the past year that evaluated the safety and efficacy of atrial septal defect devices, patent ductus occluders, and stents to treat coarctation of the aorta. The past year has also seen the emergence of old technologies that have been modified and expanded for new applications. The three areas of old technology reviewed are (1) using balloon angioplasty to palliate low birth weight infants with critical coarctation, (2) using coronary interventions in the pediatric patient, and (3) using balloon pulmonary angioplasty to treat patients with chronic thromboembolic pulmonary hypertension. Finally, this review describes the development of a new interventional technique, transcatheter implantation of a pulmonary valve, and outlines how real-time MRI in the next decade likely will replace x-ray fluoroscopy as the primary diagnostic and interventional imaging tool for the pediatric cardiologist.

Late cardiovascular complications after operative repair of coarctation of the aorta include systemic hypertension, premature coronary artery disease, aortic valve abnormalities, aortic aneurysm, and recoarctation. We report the outcome in 274 subjects greater-than-or-equal50 years after coarctation repair. Operative repair of simple coarctation was performed on 274 patients at the University of Minnesota Hospital between 1948 and 1976. Twenty patients (7%) died in the immediate postoperative period. Of the 254 survivors, 2 were lost to follow-up, 45 (18%) died at a mean age of 34 years, and 207 (81%) were alive greater-than-or-equal50 years after the original operation. Coronary artery disease and perioperative deaths at the time of a second cardiac operation accounted for 17 of the 45 late deaths. Predictors of survival were age at operation and blood pressure at the first postoperative visit. Of the 207 long-term survivors, 92 (48%) participated in a clinical cardiovascular evaluation. Thirty-two of the 92 subjects had systemic hypertension that was predicted by age at operation, blood pressure at the first postoperative visit, and paradoxic hypertension at operative repair. New cardiovascular abnormalities detected at follow-up evaluation included evidence of a previous myocardial infarction, cardiomyopathy, atrial fibrillation, moderate to severe left ventricular outflow tract obstruction, moderate aortic valve regurgitation, recoarctation, and ascending aortic dilation. Thus, long-term survival is significantly affected by age at operation, with the lowest mortality rates observed in patients who underwent surgery between 1 and 5 years of age. More than 1/3 of the survivors developed significant late cardiovascular abnormalities.

The association between obesity and hypertension is well recognized. However, the exact mechanisms whereby obesity causes hypertension are complex and multifactorial. The current article summarizes some of the known mechanisms responsible for obesity hypertension.

Objective: Our objective was to describe in children the relation of fatness and insulin resistance to the risk factors associated with the insulin resistance syndrome and to compare fasting insulin with the euglycemic insulin clamp as a measure of insulin resistance in children., Study Design: This was a random selection of participants after blood pressure screening of 12,043 students in the fifth through eighth grades. Euglycemic insulin clamp studies with an insulin infusion rate of 1 mU/kg/min and a variable infusion of 20% glucose to maintain euglycemia, that is, plasma glucose at 5.6 mmol/L. Insulin sensitivity (M(lbm)) is defined as the amount of glucose required to maintain euglycemia (milligrams of glucose infused per kilogram lean body mass per minute)., Results: Body mass index was significantly correlated with fasting insulin and significantly inversely correlated with M(lbm). Fasting insulin was significantly correlated with systolic blood pressure in both sexes, all lipids, except high-density lipoprotein-cholesterol in males and triglycerides and high-density lipoprotein-cholesterol in females, but after adjustment was done for body mass index, it was significantly related only to triglycerides. M(lbm) was significantly correlated only with triglycerides and high-density lipoprotein-cholesterol, and this did not change after adjustment was done for body mass index. A clustering effect for the risk factors was seen in children in the lowest quartile of M(lbm) (highest degree of insulin resistance) compared with children in the highest quartile of M(lbm) (lowest degree of insulin resistance)., Conclusions: As defined by M(lbm), there is an early association of insulin resistance, independent of body fat, with the risk factors. There is a significant relation between fasting insulin, as an estimate of insulin resistance, and the risk factors, but this is significantly influenced by body fatness. The clustering of risk factors according to level of M(lbm) suggests that adult cardiovascular disease is more likely to develop in children with the greatest degree of insulin resistance.

Reported experience with the transseptal approach to the left atrium for delivery of radiofrequency energy in the young patient is limited. To compare two approaches for radiofrequency ablation (RFA) in the left atrium we reviewed our experience from January 1, 1991, through February 1, 1999, in 154 procedures performed on 136 patients (mean age 12.2 years). The patients were grouped by either the retrograde aortic route (R, n = 30) or the transseptal atrial route (T, n = 106). No significant differences were found in age, weight, height, supraventricular tachycardia cycle length, or electrocardiograph characteristics (manifest vs concealed accessory pathway) between the two approaches. Comparison of the transseptal group to the retrograde aortic group revealed a significant difference in the number of catheters (mean = 4 R vs 3 T, p < 0.0001), total fluoroscopic time (71.3 min R vs 43.0 min T, p = 0.0007), diagnostic fluoroscopic time (40.2 min R vs 16.6 min T, p < 0.0001), ablation fluoroscopic time (44.7 min R vs 25.3 min T, p = 0.019), and procedure time (5.0 hours R vs 4.1 hours T, p < 0.0001). No significant difference was found in success rate, number of radiofrequency applications, or major complication rate. These data suggest that although outcomes and major complication rates are similar for the two groups, the use of fewer catheters and shorter fluoroscopic times warrant consideration of the transseptal atrial approach in young patients.

Objectives: We sought to examine the incidence and possible factors for inducible intra-atrial reentrant tachycardia (IART) in a group of patients after two stages of the Fontan sequence but before the operation., Background: Intra-atrial reentrant tachycardia occurs in 10% to 40% of patients after the Fontan operation. No data are available regarding the potential for IART after the first two stages of the Fontan sequence but before the operation., Methods: The IART induction protocol included programmed extrastimulation and rapid atrial pacing, with and without isoproterenol., Results: The median age of the study group (n = 44, 27 males) was 1.7 years (range 1.2 to 5.2). Forty patients were in sinus rhythm. Twelve patients (27%) had inducible, sustained (>1 min) IART. Three patients (8%) had inducible, nonsustained IART. Bivariate analysis revealed that patients with sustained IART were significantly older at their second operation (median 0.54 vs. 0.40 years, p = 0.05). Multivariate logistic modeling revealed that older age (> or =0.55 years) at the second palliative operation (p = 0.04), older age (> or =1.95 years) at evaluation before the Fontan sequence (p = 0.04) and female gender (p = 0.03) were independently associated with sustained IART. A trend toward a greater frequency of sustained IART was seen in those patients with moderate or severe atrioventricular valve regurgitation (p = 0.07) and in those with resection of the atrial septum (p = 0.06)., Conclusions: The rate of inducible, sustained IART in a group of patients before the Fontan operation is 27% and is associated with older age at the time of second-stage palliation, older age at pre-Fontan evaluation and female gender.

We have recently used the Amplatzer septal occluder to close Fontan fenestrations. Between June 1998 and December 1999, 13 patients underwent transcatheter occlusion of their Fontan fenestrations. Systemic blood flow decreased significantly without a concomitant decrease in pulmonary blood flow. All residual shunts detectable by oximetry were at sites separate from those into which occlusion devices were implanted. One patient developed severe tricuspid regurgitation following the procedure requiring surgical removal of the device. At the last follow-up, all patients were doing well clinically. There were no shunts detectable through or around the devices by echocardiography. Our experience indicates that the location of the fenestration within the Fontan baffle is critical to avoiding device interference with other intracardiac structures. The Amplatzer septal occluder offers an effective means of transcatheter closure of Fontan baffle fenestrations. Although more experience is needed, our current follow-up data suggest that long-term outcomes will be favorable. Cathet. Cardiovasc. Intervent. 51:301-304, 2000., (Copyright 2000 Wiley-Liss, Inc.)

Aim: To review human and animal data describing the complex interrelation between obesity hypertension, salt-sensitivity and insulin resistance., Data Synthesis: The first part of the article reviews the information available in the literature defining obesity hypertension as a salt sensitive form of hypertension and that links obesity hypertension to the presence of insulin. The second part reviews the four factors frequently cited as possible causes for this sodium retention: insulin resistance, alteration in the renin-angiotensin system, altered vascular responsiveness and alterations in the sympathetic nervous system. Special emphasis is given in an attempt to explain how each of these four factors can change pressure-natriuresis., Conclusions: There is clearly a strong relationship between obesity hypertension, sodium sensitivity and insulin resistance. The exact mechanism responsible for linking these three conditions is still unknown. However, there is ample evidence to suggest that insulin resistance, altered vascular responsiveness, altered function of the renin-angiotensin aldosterone system and altered function of the sympathetic nervous system are important in these three conditions. Further investigation is warranted to completely elucidate the complex relationship between insulin resistance, obesity hypertension and sodium sensitivity.

The extant nomenclature for therapeutic cardiac catheter interventions is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.