Novel Technique to Evaluate Pulmonary Vascular Resistance in a Patient With Aortopulmonary Window.

We report a case of a 15-month-old female presenting with a large aortopulmonary window during a medical mission. The optimal surgical correction for this patient would be based on an estimation of her pulmonary vascular reactivity. This report details the use of antegrade/retrograde flow ratios using Doppler measurements in the proximal descending aorta at baseline and while receiving 100% oxygen. A large increase in the proportion of retrograde flow under the 100% oxygen condition suggested a reactive pulmonary vascular bed. She underwent a complete repair with patch closure of the aortopulmonary window. A postoperative echocardiographic assessment showed near normal right ventricular pressures.

Coronary artery bypass grafting for Kawasaki disease.

Five patients with a history of Kawasaki disease underwent coronary revascularization at Children's Memorial Hospital (1988-2000). Acute disease occurred at 11 weeks to 5 years of age and revascularization procedures were performed at 8 months to 12 years (mean 6 years; interval from disease onset 5 months to 9 years). Surgical indications included abnormal stress testing with angiographic confirmation of severe coronary artery stenosis (n = 3), severe coronary artery stenosis with echocardiographic evidence of intracoronary thrombus (n = 1), and ischemic electrocardiogram changes and ventricular tachycardia during angiography (n = 1). All revascularization procedures used internal thoracic arteries including one free internal thoracic artery graft. There were no postoperative deaths (follow-up 1 month to 11 years). All patients are asymptomatic. One patient developed myocardial ischemia 4 years postoperatively with occlusion of the circumflex coronary artery (not previously grafted). This was treated successfully with percutaneous coronary angioplasty and stent placement. All grafts are patent with the exception of a single right internal thoracic artery graft which underwent involution 30 months postprocedure with concurrent recannulization of the right coronary artery. Coronary revascularization should be considered in the young patient with severe coronary abnormalities secondary to Kawasaki disease.

Simultaneous transcatheter closure of an atrial septal defect with an amplatzer septal occluder and radiofrequency ablation of an accessory connection.

This report describes the first case of simultaneous transcatheter closure of an atrial septal defect and radiofrequency ablation of an accessory connection. This was performed successfully on an 8-year-old boy and represents an attractive therapeutic alternative to surgical repair in this combination of relatively common cardiac conditions.

The role of stress echocardiography in children.

Exercise and pharmacological stress echocardiography are well-accepted techniques of evaluating coronary artery disease in adults. In children, however, experience with stress echocardiography is limited and continues to evolve. The objective of this focused review was to describe the experience with exercise and dobutamine stress echocardiography in the pediatric population, with an emphasis on technique, current indications, and future directions. Experience is reported in children with prior Kawasaki disease or heart transplant recipients, as well as patients with congenital coronary abnormalities. In addition, stress echocardiography has been used in patients who have undergone coronary artery bypass graft surgery to evaluate short- and long-term graft patterning. Stress echocardiography appears to be a feasible, safe, and useful modality for the noninvasive assessment of flow-limiting stenosis in the pediatric population and can be used serially in the routine follow-up and risk stratification in children at risk for coronary events.

Pediatric coronary artery bypass for Kawasaki congenital, post arterial switch, and iatrogenic lesions.

BACKGROUND: Pediatric coronary artery bypass (PCAB) has been recently employed for expanding indications to treat acquired, congenital, post arterial switch, and other iatrogenic pediatric coronary artery problems. METHODS: Between 1987 and 1998, 3 infants and 13 children (n = 16, mean age 6.1 years, range 2 months-18 years) underwent one or more internal thoracic artery (ITA) to coronary artery (CA) bypass grafts for Kawasaki disease (n = 4), congenital lesions (n = 3), post arterial switch (n = 4), and other iatrogenic obstructions (n = 5). Proximal left main CA arterioplasty was performed concurrently with ITA-CA bypass in 4 patients. RESULTS: Survival is 93.8%. All bypass grafts in surviving patients are patent 2 months-11 years postoperation. The 11 elective patients are well (NYHA I-II). The 5 emergent operations were performed in 2 infants and 3 adolescents who had poor ventricular function prior to ITA-CA bypass due to iatrogenic injuries in 3, congenital critical left main stenosis in 1, and intraoperative iatrogenic coronary injury in 1. The 3 adolescents fared worse, resulting in death in the first, cardiac transplantation in the second, and full recovery in the third. The 2 infants have steadily improving ventricular function. CONCLUSIONS: ITA-CA bypass can be successfully performed in infants and children for expanding elective and life-saving indications with excellent results. Poor preoperative ventricular function often persists, especially in those older children with iatrogenic injuries, and may result in death or cardiac transplantation.

Dobutamine stress echocardiography: experience in pediatric heart transplant recipients.

BACKGROUND: Transplant coronary arteriopathy causes late death and is difficult to detect noninvasively. Dobutamine stress echocardiography is being used for risk stratification in adult recipients at some transplant centers, thus we investigated its role in a pediatric population. METHODS: We performed 46 stress echo studies (mean age = 11.8 years; mean years post transplantation = 4.3). An atropine/dobutamine protocol (5-40 mcg/kg/min) was used to attain a predicted target heart rate. Serial echocardiographic images were acquired at baseline and at each increment of dobutamine and recovery, and were digitized online. Data were correlated with endomyocardial biopsy (n = 23), coronary angiography (n = 26) or autopsy (n = 6). All studies were well tolerated. RESULTS: Target heart rate was achieved in 41/46 (89%) studies. The mean heart rate significantly increased from 95 to 169 beats/min and mean systolic blood pressure from 123 to 153 mm Hg (p<.05). The mean peak pressure-rate product was 23,041 beats-mm Hg/min. Coronary arteriopathy was confirmed in 5 patients by angiography (n = 3) explanted heart (n = 1) or autopsy (n = 4). In this group, abnormalities included a new reversible wall motion abnormality (n = 2), left ventricular cavity dilation with stress (n = 3), ischemia (n = 2), increased mitral insufficiency (n = 1) and marked diastolic dysfunction (n = 1). A positive study predicted death or graft failure (p< .0005). CONCLUSIONS: Echocardiographic abnormalities during stress correlated with coronary arteriopathy in this small cohort of patients; however, larger multi-center studies are warranted to assess the utility of dobutamine stress echocardiography for risk stratification for coronary disease in pediatric transplant recipients.

Supraarterial decompression myotomy for myocardial bridging in a child.

A 10-year-old boy presented with a history of exertional chest pain. An electrocardiogram demonstrated an inferior apical myocardial infarction. Cardiac catheterization revealed myocardial bridging of the left anterior descending coronary artery with evidence of intramyocardial obstruction during systole. The patient underwent successful treatment with supraarterial decompression myotomy and remains symptom free at 1 year.

Doppler echocardiography with extended transesophageal atrial pacing: predicting the efficacy of permanent atrial pacing in the patient with a small left ventricle and sinus node dysfunction.

A 2100-g neonate underwent a two-ventricular surgical repair of a right ventricle-dominant unbalanced atrioventricular septal defect associated with the heterotaxy syndrome and sinus node dysfunction. Postoperative congestive heart failure persisted despite bradycardia management by temporary ventricular pacing. Spectral Doppler echocardiographic analysis of pulmonary venous inflow and aortic outflow patterns demonstrated significant improvement with transesophageal atrial pacing. Extended transesophageal pacing was performed for two days, resulting in dramatic clinical improvement. This is the first report of extended transesophageal atrial pacing complementing Doppler echocardiography predicting an improved outcome with permanent atrial pacing.

Report of the National Institutes of Health Workshop on Kawasaki Disease.

The National Institute of Allergy and Infectious Disease, National Institutes of Health convened a workshop on Kawasaki disease, May 1997, co-chaired by Drs. Karyl Barron and Stanford Shulman. The goal of the workshop was to review the latest scientific advances relating to the epidemiology, etiology, pathogenesis, treatment, and complications of Kawasaki disease, along with future therapeutic options and proposed future research directions.

Does banding the pulmonary artery affect pulmonary valve function after the Damus-Kaye-Stansel operation?

BACKGROUND: The Damus-Kaye-Stansel (DKS) operation can be an effective palliation in patients who have single-ventricle physiology and systemic outflow obstruction. Pulmonary artery banding (PAB) may be used as a preliminary procedure in these patients to limit overperfusion of the pulmonary circulation. In some series, the DKS operation has been associated with pulmonary insufficiency (PI). We retrospectively analyzed medical records of our patients who had PAB and later DKS to determine the incidence of PI in these patients. METHODS: Between 1982 and 1996, 15 patients underwent PAB before DKS. Median age at PAB placement was 7 days and median duration of PAB was 7 months. Echocardiograms obtained before PAB, before DKS, and at the most recent post-DKS follow-up were reviewed. RESULTS: Follow-up ranged from 1 to 15 years (mean follow-up, 7.5 years). One patient had trivial PI before PAB, which progressed to moderate PI at the last follow-up. Only 1 other patient had mild PI, but only at the last follow-up after DKS. CONCLUSIONS: These findings suggest that prior PAB does not appear to cause significant PI in patients slated for DKS, and the incidence of significant PI after the DKS operation is relatively low.

Abnormal systemic venous Doppler flow patterns in atrial tachycardia in infants.

Congestive heart failure due to atrial tachycardia in the neonate may be caused in part by altered preload and changes in diastolic flow characteristics. During atrial tachycardia, venous flow reversal is present. Onset of flow reversal is associated with a ventriculoatrial interval. Decreased tricuspid valve inflow mean velocity and time velocity integral, decreased diastolic duration, and delayed diastolic onset were present during tachycardia when compared with sinus rhythm.

Myocardial acoustics in pediatric allograft rejection.

BACKGROUND: Ultrasonographic tissue characterization is the assessment of physical properties of biologic tissue on the basis of quantitative analysis of its acoustic characteristics. Abnormalities in microscopic structure that occur with cardiac allograft rejection may result in characteristic alterations in myocardial acoustics. Ultrasonographic tissue characterization may allow noninvasive detection of rejection. METHODS: Findings in 22 pediatric heart transplant patients undergoing routine surveillance for rejection by endomyocardial biopsy were prospectively evaluated. Off-line ultrasonographic tissue characterization analysis was done on transthoracic echocardiograms obtained at each biopsy. Within patients, tissue characterization texture measures derived from the ultrasonographic image data were compared with histologic findings. Univariate multiple regression analysis was used to identify texture measures associated with acute allograft rejection in a subgroup (n = 8) with at least one biopsy-proven episode of moderate rejection. RESULTS: Measures of homogeneity (co-occurrence matrix correlation and heterogeneity (run-length nonuniformity) decreased with moderate rejection (p < 0.03). Homogeneity measures decreased if the patient had a previous episode of rejection. Several measures of heterogeneity (gray level difference and run-length statistics) were affected by the presence of edema. Run-length nonuniformity was the only measure that differentiated moderate rejection from edema. Discriminant analysis on all 22 patients correctly identified 96% of first rejection episodes (sensitivity 80%, specificity 64%), 93% of moderate and severe rejection episodes (sensitivity 71%; specificity 62%), and 69% of all rejection episodes (sensitivity 51%, specificity 91%). CONCLUSIONS: Histologic changes associated with moderate and severe pediatric allograft rejection as reflected by characteristic alterations in myocardial acoustics can be assessed with ultrasonographic tissue characterization. Histologic changes associated with transplantation itself (resolution of rejection and edema) also affect myocardial acoustics and must be taken into account in rejection surveillance.

Feasibility of exercise stress echocardiography for the follow-up of children with coronary involvement secondary to Kawasaki disease.

BACKGROUND: The development of coronary aneurysms as sequelae of Kawasaki disease can result in myocardial ischemia, infarction, and sudden death. Traditionally, these patients have undergone coronary angiography and nuclear stress imaging for risk stratification and follow-up. However, angiography is invasive, and both modalities expose the patient to repeated radiation, which is an important issue in children. The purpose of this study was to determine the feasibility of performing exercise stress echocardiography in children diagnosed with coronary abnormalities secondary to Kawasaki disease. METHODS AND RESULTS: Treadmill exercise stress echocardiographic studies were performed in 28 children ages 6 to 16 years. All had acute Kawasaki disease 1 to 10 years before study, and coronary artery abnormalities were identified during previous echocardiographic imaging. Patients were exercised using a standard Bruce protocol. Transthoracic echocardiographic images, obtained in the parasternal long, short, apical two- and four-chamber views immediately before and after exercise, were digitized for review and analysis. In baseline studies before exercise, wall motion abnormalities were identified in 2 patients; these segments became normal with exercise. Two patients developed new exercise-induced wall motion abnormalities that corresponded to angiographically defined critical stenosis of the left anterior descending coronary artery. No patients had resting or exercise-induced ECG evidence of ischemia. There were no adverse reactions, and 26 of 28 patients had normal exercise tolerance. CONCLUSIONS: Among patients with coronary artery involvement resulting from Kawasaki disease, exercise stress echocardiography is a safe, noninvasive procedure and may identify children with myocardial ischemia that was not detected with ECG stress test alone.

Biventricular repair of hypoplastic right ventricle assisted by pulsatile bidirectional cavopulmonary anastomosis.

The right ventricle in patients with severe outflow obstruction or atresia and a small tricuspid valve often remains too hypoplastic even after optimal palliation to tolerate biventricular repair with closure of the atrial septal defect. In these patients, nonpulsatile cavopulmonary (Glenn) anastomosis has traditionally facilitated biventricular repair. In 1989, Billingsley and associates reported the addition of a bidirectional cavopulmonary anastomosis to the definitive biventricular repair in patients with hypoplastic right ventricle, pulmonary atresia, and intact ventricular septum. The atrial septal defect was left open with an adjustable snare for later closure. We report five patients with hypoplastic right ventricle (mean diastolic volume 48.4%, mean stroke volume 40.2% of predicted value) who had the atrial septal defect closed at the time of the biventricular repair. Four patients, who had the bidirectional cavopulmonary anastomosis supplementing the biventricular repair, had no evidence of excessive right atrial or superior vena cava hypertension postoperatively. One patient, who had atypical tetralogy of Fallot with tricuspid stenosis, developed recurrent pericardial tamponade and marked hepatomegaly following conventional tetralogy repair with closure of the atrial septal defect. These complications were controlled with the addition of bidirectional cavopulmonary anastomosis 2 months later. Postoperative hemodynamic or Doppler studies in these patients revealed pulsatile flow in the entire pulmonary artery system, including the artery distal to the Glenn anastomosis. This modification of biventricular repair allows primary closure of the atrial septal defect and provides pulsatile arterial flow in the entire pulmonary artery, even when the right ventricle is significantly hypoplastic.

Echocardiographic evaluation of the aortic root and mitral valve in children and adolescents with isolated pectus excavatum: comparison with Marfan patients.

Pectus excavatum, mitral valve prolapse (MVP), and dilated aortic root occur frequently in patients with Marfan's syndrome (MS). Patients with isolated pectus excavatum (IPE) have a high prevalence of MVP, but it is not known whether aortic root dilatation is a risk in those patients. To test the hypothesis that IPE and MS represent a spectrum of connective tissue dystrophy with MV and aortic root involvement, two-dimensional (2D) echocardiography was used to measure the aortic root diameter and assess for MVP in IPE (n = 31), MS (n = 14), and normal (n = 16) gender- and age-matched patients. Aortic root was measured in parasternal long- and short-axis views, just above the aortic sinuses, at end systole, in six cardiac cycles, and averaged. Parasternal long-axis view was used to assess for MVP. Aortic root diameter in IPE patients was not different from that in normal subjects, 24 +/- 4 mm vs 22 +/- 4 mm (p = NS), respectively, both were significantly smaller than that in MS patients (30 +/- 5 mm; p less than 0.05). MVP was present in 17 of 31 (55%) IPE patients vs 12 of 14 (86%) MS patients (p = NS) and in only 1 of 16 (6%) normal subjects (p less than 0.05) vs both IPE and MS. We conclude that young patients with IPE represent an isolated form of connective tissue abnormality because of the presence of pectus excavatum and MVP, but this is different from the systemic involvement of MS because of the lack of other systemic findings, including aortic root dilatation and changes in body habitus.

Complex ventricular ectopic activity in patients less than 20 years of age with or without syncope, and the role of ventricular extrastimulus testing.

To assess the potential for ventricular tachycardia (VT), ventricular extrastimulus testing was performed in 33 young patients with complex ventricular ectopic activity defined as multiform ventricular premature complexes (VPCs), couplets or nonsustained VT, or a combination, found during electrocardiographic monitoring. There were 21 male and 12 female patients with a mean age of 11 years (range 1 to 18). Patients were divided into 2 groups based on the presence (14 patients) or absence (19 patients) of syncope. Patients with syncope had ostensibly normal hearts (9 patients) or miscellaneous heart disease (5 patients). Patients without syncope had ostensibly normal hearts (8 patients) or miscellaneous heart disease (11 patients). Ventricular stimulation protocol consisted of burst pacing and 1 to 4 programmed extrastimuli decreasing to refractoriness at 3 drive-train cycle lengths, and at 2 pacing sites (right ventricular apex and outflow tract) during the drug-free baseline state and isoproterenol infusion. No patient had VT induced with 1 or 2 extrastimuli. VT was induced in 13 of 14 patients (93%) with syncope, and in 9 of 19 patients (47%) without syncope (p less than 0.05). Using a 3-extrastimuli protocol, 8 of 14 patients (57%) with and 3 of 19 patients (16%) without syncope had VT induced (p less than 0.05). These findings suggest that VT may be the cause of syncope in young patients with complex ventricular ectopic activity.

A single intravenous infusion of gamma globulin as compared with four infusions in the treatment of acute Kawasaki syndrome.

BACKGROUND: Treatment of acute Kawasaki syndrome with a four-day course of intravenous gamma globulin, together with aspirin, has been demonstrated to be safe and effective in preventing coronary-artery lesions and reducing systemic inflammation. We hypothesized that therapy with a single, very high dose of gamma globulin would be at least as effective as the standard regimen. METHODS: We conducted a multicenter, randomized, controlled trial involving 549 children with acute Kawasaki syndrome. The children were assigned to receive gamma globulin either as a single infusion of 2 g per kilogram of body weight over 10 hours or as daily infusions of 400 mg per kilogram for four consecutive days. Both treatment groups received aspirin (100 mg per kilogram per day through the 14th day of illness, then 3 to 5 mg per kilogram per day). RESULTS: The relative prevalence of coronary abnormalities, adjusted for age and sex, among patients treated with the four-day regimen, as compared with those treated with the single-infusion regimen, was 1.94 (95 percent confidence limits, 1.01 and 3.71) two weeks after enrollment and 1.84 (95 percent confidence limits, 0.89 and 3.82) seven weeks after enrollment. Children treated with the single-infusion regimen had lower mean temperatures while hospitalized (day 2, P less than 0.001; day 3, P = 0.004), as well as a shorter mean duration of fever (P = 0.028). Furthermore, in the single-infusion group the laboratory indexes of acute inflammation moved more rapidly toward normal, including the adjusted serum albumin level (P = 0.004), alpha 1-antitrypsin level (P = 0.007), and C-reactive protein level (P = 0.017). Lower IgG levels on day 4 were associated with a higher prevalence of coronary lesions (P = 0.005) and with a greater degree of systemic inflammation. The two groups had a similar incidence of adverse effects (including new or worsening congestive heart failure in nine children), which occurred in 2.7 percent of the children overall. All the adverse effects were transient. CONCLUSIONS: In children with acute Kawasaki disease, a single large dose of intravenous gamma globulin is more effective than the conventional regimen of four smaller daily doses and is equally safe.

An alternative approach to the surgical management of physiologically corrected transposition with ventricular septal defect and pulmonary stenosis or atresia.

A modified approach to the surgical management of corrected transposition of the great vessels with ventricular septal defect and pulmonary stenosis or atresia was used successfully in two patients. The procedure consisted of performing a venous switch operation, directing the blood flow from the morphologically left ventricle (right-sided chamber) into the aorta through the ventricular septal defect and inserting a valved conduit between the left-sided morphologically right ventricle and the pulmonary artery. This approach has several advantages when compared with the traditional surgical management, which consists of closure of the ventricular septal defect and a left ventricular (right-sided chamber) to pulmonary artery conduit. It uses the morphologically left ventricle as the systemic pumping chamber, thereby minimizing long-term ventricular failure. It allows closure of the defect from the right ventricular side of the septum, thus decreasing the prevalence of complete atrioventricular block. It also avoids use of the tricuspid valve as the systemic atrioventricular valve and therefore decreases the chance of postoperative valve regurgitation.