Unrecognized pulmonary venous desaturation early after Norwood palliation confounds Gp:Gs assessment and compromises oxygen delivery.

BACKGROUND: Hemodynamic stability after Norwood palliation often requires manipulation of pulmonary vascular resistance to alter the pulmonary-to-systemic blood flow ratio (Qp:Qs). Qp:Qs is often estimated from arterial saturation (SaO2), a practice based on 2 untested assumptions: constant systemic arteriovenous O2 difference and normal pulmonary venous saturation. METHODS AND RESULTS: In 12 patients early (

Acute hemodynamic effects of increasing hemoglobin concentration in children with a right to left ventricular shunt and relative anemia.

The short-term effects of increasing hemoglobin concentration were evaluated at cardiac catheterization in seven children (aged 0.3 to 7.5 years) with a right to left ventricular shunt and relative anemia. Diagnoses were tetralogy of Fallot in six and L-transposition of the great vessels with ventricular septal defect and pulmonary stenosis in one. Before and 20 minutes after isovolumic partial exchange transfusion with 20 ml/kg packed red cells, the following variables were measured: hemoglobin, partial pressure of oxygen (PO2), oxygen consumption, oxygen saturation and pressure in the aorta, superior vena cava and right and left atria. After partial exchange transfusion, hemoglobin increased from 13.7 +/- 0.5 to 16.4 +/- 0.4 g/100 ml (p less than 0.001, mean +/- SEM). Aortic PO2 increased from 55.0 +/- 3.5 to 62.0 +/- 4.1 mm Hg (p less than 0.01) and aortic oxygen saturation increased from 84.3 +/- 2.3 to 90.9 +/- 1.3% (p less than 0.002). Effective pulmonary blood flow increased by 17% from 2.72 +/- 0.10 to 3.17 +/- 0.10 liters/min per m2 (p less than 0.01), and right to left shunt decreased by 59% from 1.44 +/- 0.29 to 0.59 +/- 0.10 liters/min per m2 (p less than 0.01). Systemic oxygen transport increased from 658 +/- 48 to 738 +/- 46 ml/min per m2 (p less than 0.002). After partial exchange transfusion, systemic vascular resistance increased from 15.9 +/- 1.1 to 20.0 +/- 1.4 units (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon valvuloplasty for critical aortic stenosis in the newborn: influence of new catheter technology.

Between 1986 and July 1990, balloon valvuloplasty was attempted in eight newborns (less than 28 days of age) with isolated critical aortic valve stenosis. Balloon valvuloplasty could not be successfully accomplished in any of the three infants presenting before 1989. Since March 1989, when improved catheter technology became available, all five neonates presenting with critical aortic stenosis were treated successfully by balloon valvuloplasty. A transumbilical approach was utilized in all four infants in whom umbilical artery access could be obtained. One newborn who was 25 days of age underwent transfemoral balloon valvuloplasty. Balloon valvuloplasty was immediately successful in all five newborns, as evidenced by a decrease in valve gradient and improvement in left ventricular function and cardiac output. Peak systolic gradient was reduced by 64% from 69 +/- 8 to 25 +/- 3 mm Hg (p = 0.005). Left ventricular systolic pressure decreased from 128 +/- 9 to 95 +/- 9 mm Hg (p = 0.02) and left ventricular end-diastolic pressure decreased from 20 +/- 2 to 11 +/- 1 mm Hg (p = 0.02). Moderate (2+) aortic regurgitation was documented in two infants after valvuloplasty. The time from first catheter insertion to valve dilation averaged 57 +/- 14 min (range 26 to 94) and the median length of the hospital stay was 4 days. With the use of recently available catheters, the transumbilical technique of balloon valvuloplasty can be performed quickly, safely and effectively in the newborn with critical aortic stenosis. It does not require general anesthesia, cardiopulmonary bypass or a left ventricular apical incision and it preserves the femoral arteries for future transcatheter intervention should significant aortic stenosis recur.

Determinants of successful balloon valvotomy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum.

OBJECTIVES: This study reviewed our experience with percutaneous balloon valvotomy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum and defined the anatomic and hemodynamic characteristics of infants in whom this procedure is successful and provides definitive therapy. BACKGROUND: Unlike children with valvular pulmonary stenosis, the follow-up of infants with critical pulmonary stenosis undergoing percutaneous balloon valvotomy is limited. METHODS: Between December 1987 and August 1992, percutaneous balloon valvotomy was attempted in 12 infants with critical pulmonary stenosis (n = 10) or pulmonary atresia with intact ventricular septum (n = 2). Two outcome groups were identified: Group A patients are acyanotic, have mild residual pulmonary stenosis and have not required operation; Group B patients have required operation. RESULTS: Of the 12 infants, 11 had a successful balloon valvotomy procedure. Group A patients (n = 7) have a residual gradient of 22 +/- 18.7 mm Hg (mean +/- SD) at follow-up of 3.2 years (range 1.2 to 5.0). In Group B (n = 5), operation was required for inability to cross the pulmonary valve (n = 1) or persistent severe hypoxemia for > or = 2 weeks after valvotomy (n = 4). Significant differences (p < or = 0.01) between the two groups (Group A vs. Group B) were identified in pulmonary valve annulus (Z value) 8.1 mm (-1.1) versus 5.5 mm (-3.4); tricuspid valve annulus (Z value) 14.0 mm (0.8) versus 8.8 mm (-1.8); right ventricular volume 65 versus 29 ml/m2; and Lewis index 10.9 versus 8.9. CONCLUSIONS: Percutaneous balloon valvotomy is effective and likely to provide definitive therapy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum who have a tricuspid valve annulus > 11 mm, pulmonary valve annulus > or = 7 mm and right ventricular volume > 30 ml/m2.

Balloon valvuloplasty for recurrent aortic stenosis after surgical valvotomy in childhood: immediate and follow-up studies.

The immediate and intermediate-term effects of balloon valvuloplasty were assessed at cardiac catheterization in nine children with recurrent stenosis after a previous surgical aortic valvotomy. At valvuloplasty the patients ranged in age from 0.35 to 16 years and had undergone surgical valvotomy 0.3 to 12.5 years previously. Balloon valvuloplasty immediately reduced the peak systolic aortic stenosis gradient by 53%, from 88 +/- 9 (mean +/- SEM) to 41 +/- 6 mm Hg (p = 0.004). The left ventricular systolic pressure was reduced from 189 +/- 8 to 157 +/- 8 mm Hg (p = 0.001) and the left ventricular end-diastolic pressure from 17 +/- 1 to 14 +/- 2 mm Hg (p = 0.025). The heart rate and cardiac index remained unchanged. Before valvuloplasty, one patient had 1 + and two patients had 2+ aortic insufficiency. In six of nine patients, balloon valvuloplasty caused no change in the degree of valvular insufficiency. Two patients had a 1 + increase (from 0 to 1 + insufficiency in both), and one patient with no insufficiency developed 2+ aortic insufficiency. Elective follow-up catheterization was performed 0.8 to 2.5 years (mean 1.5 +/- 0.2) after valvuloplasty. At follow-up, the peak aortic stenosis gradient remained significantly reduced from the gradient before valvuloplasty (37 +/- 5 versus 85 +/- 10 mm Hg, p = 0.002). The gradient had not changed significantly from that measured immediately after valvuloplasty (37 +/- 5 versus 38 +/- 5 mm Hg, p = 0.75). At follow-up, aortic insufficiency had decreased from that immediately after valvuloplasty in three patients and had increased in two.(ABSTRACT TRUNCATED AT 250 WORDS)

Intermediate-term outcome after pulmonary balloon valvuloplasty: comparison with a matched surgical control group.

To assess late (4 to 5 years) gradient reduction after pulmonary balloon valvuloplasty in childhood, and to compare the effectiveness of valvuloplasty with that of surgical valvotomy, 20 valvuloplasty-treated children and their age- and gradient-matched surgical control patients underwent prospective, noninvasive evaluation. The average age at intervention was 4.3 +/- 1 years for the valvuloplasty group versus 4.7 +/- 0.8 years for the surgical control group (p = NS). Before intervention the peak systolic pulmonary stenosis gradient was 76 +/- 5 and 74 +/- 4.4 mm Hg for the valvuloplasty and surgery groups, respectively (p = NS). Late evaluation consisted of clinical examination, two-dimensional echocardiogram and Doppler study, 24-hour Holter monitoring, 12-lead electrocardiogram, exercise treadmill study and chest radiograph performed an average of 5.3 +/- 0.3 years after valvuloplasty and 11.7 +/- 0.5 years after surgery (p less than 0.01). The patients treated with balloon valvuloplasty had no evidence of restenosis; the residual pulmonary stenosis gradient at follow-up was 24 +/- 2.7 mm Hg (range 8 to 48) versus 35 +/- 3.6 mm Hg (range 19 to 70) immediately after valvuloplasty (p = NS). Comparison of the late residual gradients between treatment groups showed no hemodynamically significant difference (24 +/- 2.7 versus 16 +/- 1.5 mm Hg, balloon versus surgery; p less than 0.01). However, there was, a significant difference in the degree and severity of pulmonary valve insufficiency and ventricular ectopic activity between groups. In the balloon valvuloplasty group 11 patients had no pulmonary insufficiency, and the remaining 9 had mild insufficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid progression of aortic aneurysms after patch aortoplasty repair of coarctation of the aorta.

OBJECTIVES: This study was undertaken to evaluate the progression of aortic aneurysms after patch aortoplasty repair of coarctation of the aorta. BACKGROUND: Previous studies demonstrated a 5% to 25% incidence rate of repair site aneurysm 3 to 18 years after patch aortoplasty repair of coarctation. The natural history of aneurysmal progression in this disease entity has not previously been examined. METHODS: Twenty-nine patients were identified 5.6 +/- 1 years (mean +/- SE) postoperatively and classified into two groups: Group A, aneurysm (n = 7); Group B, no aneurysm (n = 22). The presence of an aneurysm was defined angiographically as a ratio of the repair site diameter to diaphragmatic aortic diameter (aortic ratio) greater than or equal to 1.5. A 23% prevalence (7 of 29) of aortic aneurysm was identified. One patient in Group A underwent semiemergency aneurysmectomy and two patients in Group B were lost to follow-up. The remaining 26 patients were reevaluated 3 to 5 years later by clinical examination and chest radiography. Aortograms were performed in all patients with suspected aneurysm formation or progression. RESULTS: Five of six patients in Group a demonstrated progressive aneurysmal dilation documented by an increase in aortic ratio from 1.64 +/- 0.06 to 2.04 +/- 0.2 (p = 0.03) and an increase in absolute aneurysm diameter from 2.5 +/- 0.3 to 3.6 +/- 0.5 cm (p = 0.006). Only 1 of 20 patients in Group B had evidence of new aneurysmal dilation (p less than 0.05 vs. Group A). Four patients in Group A have undergone elective aneurysmectomy, with equal distribution of true and pseudoaneurysms by pathologic examination. CONCLUSIONS: Aortic aneurysm formation is common after patch aortoplasty repair of coarctation of the aorta. The majority of patients with an aortic ratio greater than or equal to 1.5 will show significant progressive aneurysmal dilation within 3 to 5 years.

Exercise-induced hypertension after repair of coarctation of the aorta: arm versus leg exercise.

The etiology of exercise-induced upper limb hypertension after repair of coarctation of the aorta is unknown. We hypothesized that blood flow across the coarctation repair site is a major determinant of such exercise-induced hypertension. Because arm ergometry should produce a smaller increase in descending aortic blood flow than treadmill exercise, we compared the changes in upper limb pressure and the coarctation gradient produced by each type of exercise at equivalent levels of heart rate and peak oxygen consumption in 28 children with repaired coarctation of the aorta. The children were classified into three groups: Group I, resting gradient less than 15 mm Hg and treadmill gradient less than 20 mm Hg; Group II, resting gradient less than 15 mm Hg and treadmill gradient greater than 20 mm Hg; and Group III, resting gradient greater than or equal to 15 mm Hg. Twelve children with no heart disease served as control subjects. All children were exercised to exhaustion with 45 minutes' rest between the two exercise protocols. There were no differences in maximal heart rate and oxygen consumption between the two types of exercise. In all groups, treadmill exercise produced a larger increase in arm systolic blood pressure and arm-leg gradient than did arm exercise. With treadmill exercise coarctation Groups II and III developed a greater rise in both arm-leg gradient and arm systolic pressure than was observed in the control subjects (p less than 0.05). However, with arm exercise, Group III developed a significantly greater rise in both arm pressure and arm-leg gradient (p less than 0.05) than was observed in the control subjects.

Hemodynamic and clinical effects of oral levodopa in children with congestive heart failure.

OBJECTIVES: This study was undertaken to evaluate the safety, efficacy and pharmacodynamic variables of oral levodopa in pediatric patients with congestive heart failure refractory to standard therapy. BACKGROUND: Therapeutic options for children with congestive cardiomyopathies are limited to digoxin, diuretic agents and angiotensin-converting enzyme inhibitors. Previous work in adults with congestive heart failure has shown a short-term effectiveness of levodopa and improvement of cardiac function. METHODS: Baseline two-dimensional and M-mode echocardiography, surface electrocardiography, Holter monitoring and exercise testing, when applicable, were performed. Levodopa was administered in a dose escalation scale from 8 mg/kg body weight per dose to 20 mg/kg per dose over 3 days with concomitant metoclopramide and pyridoxine. Catecholamine levels at initiation of the trial and throughout dose escalation were measured, with echocardiographic and electrocardiographic correlation. After 24-h drug washout, cardiac catheterization was performed both before and after administration of levodopa. RESULTS: Between February 1992 and December 1995, nine children (age 10 +/- 1.7 years, weight 27.8 +/- 4.3 kg) were enrolled in this study. At cardiac catheterization, serum dopamine levels rose from 108.5 +/- 59.2 pg/ml to 1,375.8 +/- 567.9 pg/ml (p = 0.03) at 100 +/- 14.8 min after levodopa administration without a significant change in serum norepinephrine or epinephrine levels. Paralleling these increases, there were significant changes in the cardiac index (1.7 +/- 0.3 to 3.2 +/- 0.7 liters/min per m2), stroke volume index (16.1 +/- 3.2 to 31.2 +/- 7.0 ml/m2 per min), oxygen consumption (138.6 +/- 24.4 to 188.3 +/- 30.8 ml/min per m2) and systemic vascular resistance (36.8 +/- 8 to 21.9 +/- 5.5 indexed Wood's units; all p < 0.01). There was a significant reversal of the daily fluid volume output/input ratio from 0.8 +/- 0.1 to 1.2 +/- 0.1 (p < 0.01). Levodopa administration was complicated by hypertension or tachycardia, or both, requiring a dose reduction in three patients, and by significant gastrointestinal distress in one. There was sustained symptomatic improvement a median of 19.5 months after drug initiation in seven of the patients. CONCLUSIONS: These preliminary data support the hemodynamic value of oral levodopa in the treatment of severe congestive heart failure in children.

Intermediate-term results of Phase I Food and Drug Administration Trials of buttoned device occlusion of secundum atrial septal defects.

OBJECTIVES: This study was conducted to evaluate the intermediate-term results of the multi-institutional U.S. trial of the buttoned device for transcatheter closure of atrial septal defects (ASDs). BACKGROUND: The trial was conducted in three centers (University of Arizona, University of Michigan and University of Wisconsin) under a Food and Drug Administration (FDA)-approved clinical trial with investigational device exemption. Only short-term follow-up is known. METHODS: All 46 patients who had successful implantation of the device were prospectively followed up. Patients were evaluated at 1, 6 and 12 months after device occlusion and yearly thereafter. RESULTS: This cohort was followed up from 51 to 68 months (mean 60.8, median 62). Patient ages ranged from 1 to 62 years (median 4); weights ranged from 10 to 105 kg (median 18); and stretched ASD sizes were 14 +/- 4 mm (left to right shunts) and 10 +/- 3 mm (right to left shunts). Of the 46 patients, 45 (98%) had effective occlusion of their ASD, and 34 (74%) had complete ASD closure. The incidence of residual shunts decreased from 65% (30 of 46 patients) at 1 month after device placement to 27% (12 of 45 patients) at last follow-up. All residual shunts were quantitated as trivial. Only two patients (4%) required reintervention for significant residual defects. There were no cases of endocarditis or thromboembolism in 224 patient-years of follow-up. CONCLUSIONS: In up to 5.5 years of follow-up, the buttoned device provided effective closure in 98% of patients in whom the device was successfully implanted. The incidence of residual shunts decreased during follow-up, and no instances of endocarditis or thromboembolism were observed.

Sinus of Valsalva aneurysm complicating bacterial endocarditis in an infant: diagnosis with two-dimensional and Doppler echocardiography.

Sinus of Valsalva aneurysm is a rare complication of bacterial endocarditis in infancy and childhood. This report describes an infant with congenital aortic stenosis who developed bacterial endocarditis after abdominal surgery and placement of indwelling central venous catheters for long-term parenteral nutrition. Bacterial endocarditis in this infant was complicated by the development of an aneurysm of the left sinus of Valsalva. Surgical intervention was necessary because of gradual expansion of the aneurysm with compression of the adjacent right pulmonary artery and descending aorta. Two-dimensional and Doppler echocardiography proved useful for the initial diagnosis and serial follow-up of this unusual disorder and for its successful surgical management.

Surgical repair is safe and effective after unsuccessful balloon angioplasty of native coarctation of the aorta.

Since 1985 balloon angioplasty, followed by surgical repair if angioplasty is unsuccessful, has been used as a treatment strategy for eligible children with discrete native coarctation of the aorta. Although balloon angioplasty has been successful in most patients, this strategy is appropriate only if surgery is safe and effective in children in whom angioplasty does not succeed. To address this issue, the surgical procedure and clinical outcome in 11 children who underwent surgery after unsuccessful balloon angioplasty (defined as a residual systolic gradient greater than 20 mm Hg in 10 and a saccular aneurysm in 1) were evaluated. Data for subjects were compared with data for a control group of seven children who had surgical repair of a discrete coarctation without prior angioplasty during the same time period. In the study group, balloon angioplasty was performed at 4.3 +/- 1.2 years of age, resulting in a balloon/isthmus ratio of 0.98 +/- 0.05 and decreasing mean peak systolic gradient from 54 +/- 3 to 27 +/- 2 mm Hg (p less than 0.001). Follow-up angiography (n = 7) or nuclear magnetic resonance imaging (n = 4) documented a discrete residual stenosis in 10 patients and a small saccular aneurysm in 1. Collateral circulation decreased in three patients. The subsequent surgical procedure and its outcome were similar in the study and control groups. Chylothorax was the only complication, occurring in one child from each group. No paraplegia or mortality occurred. Pathologic examination revealed irregular intimal surfaces with small flaps of intima in 5 of 10 resected specimens from the study group and in 2 of 6 from the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term outcome after repair of coarctation in infancy: subclavian angioplasty does not reduce the need for reoperation.

To assess the influence of surgical technique on the need for reoperation after coarctation repair in infancy, follow-up data were analyzed for 125 consecutive infants (less than 12 months) who underwent repair of coarctation of the aorta by subclavian angioplasty or resection and end to end anastomosis. Sixty-three infants underwent coarctation repair by resection between 1960 and 1980, and 62 underwent subclavian angioplasty between 1977 and 1985. The mean age (+/- SEM) at operation for infants with subclavian flap angioplasty was 1.54 +/- 0.93 months and for infants with resection was 2.70 +/- 0.93 months (p = 0.02). There was no difference between the groups in patient weight at initial repair or the proportion of patients with complex anatomy or aortic arch hypoplasia. Follow-up duration for the subclavian flap group was 2.55 +/- 0.51 years (range 0.3 to 8.2), and for the resection group was 7.97 +/- 3.61 years (range 0.6 to 21). Indication for reoperation was the presence of a coarctation gradient at rest of 40 mm Hg or greater and arm hypertension. Reoperation was required in 5 patients in the subclavian flap group and 12 patients in the resection group. The mean reoperation rate after subclavian flap repair was 0.0356 reoperations per patient-year, and after resection was 0.0342 reoperations per patient-year (p = 0.94). To determine an individual's risk of requiring reoperation from these group measures, a reoperation risk model was developed. The risk of reoperation by the fifth postoperative year was found to be 16.3% after subclavian flap repair and 15.7% after resection.(ABSTRACT TRUNCATED AT 250 WORDS)

Follow-up of coil occlusion of patent ductus arteriosus.

OBJECTIVE: We sought to determine the prevalence and fate of residual ductal shunting following coil occlusion of patent ductus arteriosus. BACKGROUND: Although transcatheter coil occlusion of patent ductus arteriosus has gained popularity, few follow-up data have been reported. METHODS: A review of 75 patients who underwent coil occlusion was performed. Residual shunting was investigated by Doppler echocardiography in follow-up. Angiograms were reviewed to obtain minimal ductal diameter and ductal angiographic type. RESULTS: Residual shunts were found in 31 patients (41%) on the day of the procedure, and of these, spontaneous closure was noted in 17 (55%) at 2 weeks to 20 months of follow-up. Of the 75 patients studied, 5 (7%) required a second coil procedure, and 10 (13%) remained with persistent residual shunts at most recent follow-up. Actuarial analysis estimated a 6 +/- 5% prevalence of residual shunts 20 months after a single coil procedure and 3 +/- 3% after all coil procedures. Minimal ductal diameter was associated with immediate complete ductal occlusion by a single coil. These patients had significantly smaller (p = 0.003) minimal ductal diameters (1.2 +/- 0.7 mm) than those who required two coils during their initial procedure to achieve immediate occlusion (1.9 +/- 0.7 mm), those who required a second coil procedure (2.0 +/- 0.9 mm), those who had spontaneous closure of residual shunts (1.9 +/- 0.7 mm) and those with persistent residual shunts (2.0 +/- 0.9 mm). No association was identified between ductal angiographic type and outcome of coil occlusion. No late adverse clinical events of coil occlusion or evidence of recanalization was found. CONCLUSIONS: Small residual shunts are common after coil embolization of patent ductus arteriosus, but most close spontaneously. Actuarial analysis estimates complete closure in 94% at 20 months, and reintervention was required in only 7% of patients.

Comparison of high pulse repetition frequency and continuous wave Doppler echocardiography for velocity measurement and gradient prediction in children with valvular and congenital heart disease.

To compare the ability of high pulse repetition frequency and continuous wave Doppler echocardiography to detect the peak velocity of a jet flow disturbance and to predict pressure gradients accurately, two groups of children with valvular or congenital heart disease were examined using both Doppler techniques. The use study group included 84 children or adolescents (aged 1 day to 19 years) who underwent examination in the echocardiography laboratory with both Doppler techniques in a randomized sequence. The peak velocity recorded with high pulse repetition frequency Doppler echocardiography was compared with the peak velocity recorded with the continuous wave technique. The accuracy study group included 41 children or adolescents (aged 1 day to 16 years) who underwent examination with both Doppler techniques at the time of cardiac catheterization. Doppler pressure gradients were calculated from the peak velocity using the simplified Bernoulli equation and were compared with peak instantaneous gradients and peak to peak gradients measured at catheterization. In the use study, a high correlation was found between peak velocities detected by high pulse repetition frequency and continuous wave Doppler echocardiography (r = 0.94, SEE = 0.28 m/s). In the accuracy study, close correlations were found between measured peak to peak pressure gradients and pressure gradients calculated from continuous wave (r = 0.95, SEE = 7.9 mm Hg) and high pulse repetition frequency Doppler echocardiography (r = 0.94, SEE = 8.7 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous balloon angioplasty for native coarctation of the aorta.

Twenty-six children, aged 5 weeks to 14.7 years, underwent percutaneous balloon angioplasty for a discrete native coarctation of the aorta. The procedure reduced the systolic coarctation gradient acutely in all children. The mean systolic gradient decreased by 75%, from 48.6 +/- 2.4 before to 12.3 +/- 1.9 mm Hg after angioplasty (p less than 0.001). Long-term results were evaluated in 14 children by follow-up catheterization 12 to 26 months (mean 15.3) after angioplasty. At follow-up, the residual gradient averaged 11.7 +/- 3.7 mm Hg (range -5 to 36) and had not changed from that measured immediately after angioplasty (p = 0.64). Compared with preangioplasty values, the systolic pressure in the ascending aorta had improved substantially at follow-up (116.0 +/- 3.2 versus 143.9 +/- 3.1 mm Hg, p less than 0.001). On the basis of follow-up data, two groups of children were identified: Group 1 consisted of nine children with a good result, defined as a residual gradient less than 20 mm Hg and no aneurysm; Group 2 consisted of five children with a poor result, four with a residual gradient greater than 20 mm Hg (range 25 to 36) and one with an aneurysm at the dilation site. There was no statistical difference between the two groups in age at angioplasty, balloon size, ratio of balloon to isthmus diameters, follow-up duration, heart rate or cardiac output. However, of the four children with a residual gradient greater than 20 mm Hg, two were the youngest in the study, and in two the aorta was inadvertently dilated with a balloon 4 to 5 mm smaller than the isthmus diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Quinidine syncope in children.

Quinidine syncope and factors associated with it are well known among adult patients treated for cardiac arrhythmias. To define factors that may influence the occurrence of syncope in children taking quinidine, the clinical, anatomic, electrocardiographic, roentgenographic and pharmacologic data were compared in six patients with syncope (Group A) and 22 patients without syncope (Group B). There was a significant (chi-square = 10.2, p = 0.001) relation between heart disease and quinidine syncope: all six Group A (syncopal) patients had heart disease whereas 15 of the 22 Group B (non-syncopal) patients had no structural heart disease. In contrast, no significant difference was noted between Group A and Group B patients in mean age (11.4 versus 11.4 years), mean quinidine serum concentration (2.9 versus 2.3 micrograms/ml), mean corrected QT interval before quinidine (0.43 versus 0.40 second) or mean corrected QT interval during quinidine therapy (0.46 versus 0.46 second) or between those taking digitalis and those not. Two of the six Group A (syncopal) patients died during therapy, one 6 days after initiating therapy and one suddenly at home 6 months after beginning quinidine. Another two of the six Group A patients exhibited hypokalemia (both 2.9 mEq/liter) at the time of syncope, 2 weeks and 6 months, respectively, after initiation of quinidine therapy; both survived. Syncope occurred within 8 days of initiation of quinidine therapy in three of the six patients. Sustained ventricular tachycardia was observed during quinidine associated arrhythmia in three of six patients with syncope; nonsustained ventricular tachycardia or complex ventricular ectopic activity while on this therapy was observed before syncope in the other three patients in Group A.(ABSTRACT TRUNCATED AT 250 WORDS)

A reversible pulmonary artery band: preliminary experience.

Pulmonary artery banding has become an infrequently used surgical technique. However, if a band was developed that could be relieved without the need for open heart surgery, it is likely that pulmonary artery banding would be used more frequently in the management of infants with congenital heart disease. Such a pulmonary artery band was placed in seven 1 week old mongrel puppies by using a loop of an absorbable suture material (Vicryl). One dog died at 2 months as a result of right ventricular failure. The remaining six dogs underwent cardiac catheterization and pulmonary balloon angioplasty at 6 months of age. After measuring pulmonary artery, right ventricular and aortic pressures and performing a right ventricular angiogram, balloon angioplasty of the band site was performed. A 20 mm balloon angioplasty catheter (Medi-Tech) was used in all dogs. Balloon angioplasty decreased right ventricular pressure from 101 +/- 19 to 42 +/- 3 mm Hg (p less than 0.05) and right ventricular systolic outflow tract gradient from 59 +/- 14 to 7 +/- 2 mm Hg (p less than 0.03), and increased the size of the band site from 8.7 +/- 0.03 to 14.9 +/- 0.5 mm (p less than 0.01). All dogs were recatheterized 2 months after angioplasty and were then killed for pathologic evaluation. At follow-up catheterization, right ventricular pressure, right ventricular outflow tract gradient and pulmonary artery size at the band site remained at the values obtained immediately after angioplasty. Postmortem examination demonstrated that there was no evidence of pulmonary artery damage. Although these studies are preliminary, they suggest that a reversible pulmonary artery band can be performed.

Comparison of single and double balloon valvuloplasty in children with aortic stenosis.

To compare the effectiveness of the single and double balloon techniques, the short-term results of percutaneous balloon valvuloplasty were assessed in two consecutive groups of children with valvular aortic stenosis. In 16 children (aged 3 months to 17 years) the single balloon technique was utilized; the ratio of balloon diameter to valve anulus diameter was 0.96 +/- 0.03 (mean +/- SEM). In 11 children (aged 3 months to 21 years) the double balloon technique was utilized in which two balloons are positioned across the valve and inflated simultaneously; the ratio of the balloon diameter sum to valve anulus diameter was 1.32 +/- 0.05. The groups were similar in age, weight, cardiac output, prevalvuloplasty gradient and valve anulus diameter. Overall, valvuloplasty reduced the peak systolic gradient by 53% from 80 +/- 4 to 38 +/- 3 mm Hg (p less than 0.0001). In the single balloon group the gradient decreased from 82 +/- 6 to 46 +/- 4 mm Hg (p less than 0.0001), whereas in the double balloon group the gradient decreased from 76 +/- 5 to 26 +/- 4 mm Hg (p less than 0.0001). The peak systolic gradient after valvuloplasty was 43% lower in the double balloon group (p less than 0.01). Furthermore, the single balloon technique reduced the gradient by an average of 43% compared with a 67% reduction with the double balloon technique (p less than 0.001). The short-term complications of valvuloplasty were similar, with an increase in aortic insufficiency occurring in three children in each group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic aneurysm after patch aortoplasty repair of coarctation: a prospective analysis of prevalence, screening tests and risks.

Twenty-nine children were evaluated prospectively for the presence of an aortic aneurysm at the repair site 1 to 19 years after patch aortoplasty repair of coarctation of the aorta. In each child, noninvasive evaluation included a chest X-ray film, computed tomography of the chest and two-dimensional echocardiography. The presence and size of an aortic aneurysm were determined quantitatively by measuring the ratio of the diameter of the thoracic aorta at the repair site to the diameter of the aorta at the diaphragm (aortic ratio). An aortic ratio of greater than or equal to 1.5 was judged abnormal and was shown to be significantly greater than the aortic ratio of a normal control group. An aortogram was obtained in each child if any noninvasive screening test was found to be abnormal. As assessed by the aortogram, the prevalence of aortic aneurysm was 24% in this patient group. The sensitivity of echocardiography and chest computed tomography for detecting an aneurysm was 71% and 66%, and the specificity 76% and 85%, respectively. The chest X-ray film was 100% sensitive and 68% specific in determining the presence of an aneurysm. Although the data are not statistically significant, they suggest that children undergoing patch aortoplasty as the primary procedure (rather than a reoperation after earlier resection), and children in whom a Dacron patch is utilized may be at increased risk for aneurysm formation.(ABSTRACT TRUNCATED AT 250 WORDS)