Michael W.H. Patterson

Pulmonary vascular disease in neonates with transposition of the great arteries and intact ventricular septum.

BACKGROUND--Progressive pulmonary vascular disease in surgically unrepaired transposition of the great arteries with or without ventricular septal defect had been frequently described in the past. Occurrence of progressive pulmonary vascular disease has been reported even after atrial switch procedure done at three months of age. With the advent of neonatal surgical repair, this problem is virtually non-existent. There is a small subgroup of infants with transposition of the great arteries who show pulmonary vascular disease in the neonatal period that can adversely affect the surgical outcome. The clinico-pathological correlation in this group of patients was studied. OBSERVATIONS--Three patients, with transposition of the great arteries and intact ventricular septum, who showed histological evidence of pulmonary vascular disease in the neonatal period or early infancy are described. Two of these patients, continued to have poor systemic oxygenation despite adequate atrial communication. One patient had a close ductus arteriosus within the first two hours of birth while on prostaglandin E1 infusion. CONCLUSIONS--In the absence of left ventricular outflow tract obstruction, a poor response to atrial septostomy suggests pulmonary hypertension and pulmonary vascular disease. Antenatal constriction of the ductus arteriosus may contribute to such changes in pulmonary vasculature.

Kawasaki Disease in the Older Child

Objectives. To determine the prevalence of Kawasaki disease in older children and to evaluate its clinical presentation, time to diagnosis, and outcome in comparison with younger patients with the disease. Methodology. A retrospective analysis of all patients discharged with a diagnosis of Kawasaki disease at a pediatric tertiary care hospital over a 12-year period. Results. A total of 133 patients were included in this study; 7.5% were 9 years of age or older at the time of illness. Patients were grouped by age: infants included children age 1 to 8 years of age and children 9 years of age or older. Older children had a higher frequency of abnormal cardiovascular physical examination (50%) versus children (6%) and infants (10%). The older age group and the infants had a higher prevalence of coronary artery abnormalities and poor left ventricular function than did the 1- to 8-year-olds. Eighty percent of the older children had coronary arteries that were either dilated or aneurysmal, and 30% demonstrated left ventricular dysfunction on initial echocardiography. The number of days to diagnosis after meeting the diagnostic criteria was 5.8 ± 2.3 for infants, 5.2 ± 1.5 for older children, and 1.9 ± 0.3 for children. Older children had a complicated course of Kawasaki disease compared with younger patients. Conclusion. We found a higher prevalence of older children with Kawasaki disease at our center than has previously been reported. Older patients, as well as infants, had a higher rate of coronary artery abnormalities than did the children between 1 and 8 years of age. Older age at the time of illness or a delay in treatment may be important factors in determining cardiac involvement in Kawasaki disease.

Double-blind placebo-controlled trial of corticosteroids in children with postpericardiotomy syndrome

SummaryThe objective of this study was to assess the efficacy of corticosteroids in hastening the recovery of children with postpericardiotomy syndrome, using a randomized double-blind placebo-controlled trial in a tertiary care referral center for pediatric cardiology and cardiac surgery. Twenty-one children, 6 months of age or older (mean age 3.9 years) with postpericardiotomy syndrome following open or closed heart surgery were administered either prednisone 2 mg/kg/day reducing to zero over 14 days (n=12) or placebo (n=9). Progress was monitored by daily clinical assessment and alternate day cross-sectional echocardiograms. The primary measures of efficacy were the number of patients in remission at 72 h and at 1 week. No difference in remission rates were found at 72 h, but at 1 week significantly more children treated with prednisone were in remission (placebo 3/9; prednisone 10/12,p=0.03). A trend to faster resolution of all symptoms and signs was seen in the prednisone-treated group but this was not associated with earlier hospital discharge. Enlargement of pericardial effusion was seen in two children treated with steroids. No complications of treatment were encountered. Prednisone hastens the recovery of children with postopericardiotomy syndrome. Pericardial effusions may increase in size despite the use of corticosteroids.

Pulmonary Artery Banding: Results and Current Indications in Pediatric Cardiac Surgery

The results of pulmonary artery banding in 144 patients seen from 1971 to 1984 were reviewed. Age ranged from 1 week to 4 years (median, 8 weeks) and weight, from 1.1 to 16 kg (median, 4 kg). The patients were divided into three major groups: Group 1, defects without mixing disorders (ventricular septal defect, double-outlet right ventricle [DORV], atrioventricular septal defect); Group 2, defects with mixing disorders (transposition of the great arteries, DORV, single ventricle, tricuspid atresia); and Group 3, miscellaneous (mitral atresia, left ventricular hypoplasia, truncus complex). The diagnostic group influenced survival (p = 0.0035). In Group 1, 88.8% survived, but only 64.9% survived in Groups 2 and 3 combined. The presence of patent ductus arteriosus or coarctation of the aorta had no effect on survival (p = 0.61 and p = 0.7, respectively). The clinical condition at thirty days after pulmonary artery banding was good in 35.1% and fair in 46.9% of the patients. When the data were divided into the three periods 1971 through 1974, 1975 through 1979, and 1980 through 1984, which included 28, 49, and 67 patients, respectively, a significant improvement in survival was observed from the early (64.3%) to the late period (92.5%) (p = 0.0009). Patients weighing less than 4 kg had a significantly lower survival in the period 1971 through 1974 (37.5% versus 91.67%). No significant difference in survival was detected in the late period, 1980 to 1984 (90% versus 94.6%), between patients weighing less than and those weighing more than 4 kg. Pulmonary artery banding is clinically satisfactory in small infants and children with complex anomalies.

Treatment of grafts and major vessel thrombosis with low-dose streptokinase in children.

Low-dose streptokinase infusions have been used in 8 of our patients. Five of these were newborns who had major vessel occlusion. Four babies had extensive aortic thrombosis and hypertension producing congestive aortic thrombosis and hypertension producing congestive heart failure. One baby had caval and renal vein thrombosis and was in renal failure. Two infants with cyanotic heart disease and 1 with arteritis had occluded prosthetic grafts, which were reopened completely. Two grafts were between the subclavian and pulmonary arteries (Blalock-Taussig shunt), and one was between the abdominal aorta and right renal artery. In each patient, the thrombolytic agent was delivered directly to the area of thrombosis by three or four percutaneously inserted French catheters. The dose of streptokinase used was between 50 and 100 U/kg/hr. Therapy lasted for 2 to 11 days. Major bleeding was anticipated, and it occurred in 1 patient. Low-dose streptokinase infusion is a safe and effective treatment for a variety of thrombotic problems in infants and children.

Aortic insufficiency in association with juvenile ankylosing spondylitis

vitro m e a s u r e m e n t o f 22Na influx into red blood cells will establish the diagnosis o f Liddle syndrome pr ior to therapy in pat ients who have hyper tens ion and hypokalemia wi thou t demons t r ab l e renal or adrenal pathology. The demons t r a t i on o f increased t ranspor t o f sodium into erythrocytes and the absence of mineralocor t icoid excess suppor t the view that Liddle syndrome is due to a general ized m e m b r a n e abnormal i ty .

Balloon Angioplasty of Right Ventricular Outflow Tract Conduits

Abstract. Palliation of complex congenital heart disease, requiring reconstruction of the right ventricular outflow tract (RVOT), is standard practice. Survival of the homograft is a limiting factor. We examined the role of balloon angioplasty (BAP) in prolonging conduit life. Twelve patients underwent 15 BAP procedures between February 1989 and October 1997. The median age at conduit insertion was 28 months with detection of a significant echo gradient 42 months later. Calcification of homografts, with attendant obstruction and valve dysfunction, was present in all patients. BAP was performed within 1 month of echocardiography and reduced the gradient from a median of 57 to 38 mmHg (p < 0.0005). Echocardiographic follow-up showed persistent gradients (median 68 mmHg) and 11/12 patients went on to conduit replacement after BAP. Only one patient had replacement deferred as a result of BAP. Complications requiring intervention occurred in 20% of the procedures and included bleeding and an unusual balloon fracture. Although BAP can reduce the pressure gradient across the RVOT conduit, the effect is transient and the delay of surgery is not due to improved hemodynamic function. Approximately 10% of cases will benefit from BAP alone, but given the high rate of complications, we do not recommend this procedure as a means of prolonging conduit life.

Autoantibody production after cardiopulmonary bypass with special reference to postpericardiotomy syndrome

A prospective study of children undergoing open heart surgery with cardiopulmonary bypass showed that many of them produced autoantibodies. No association was found between these antibodies, including anticardiolipin antibodies, and the occurrence of postpericardiotomy syndrome.

Clinical and echocardiographic evidence suggesting afterload reduction as a mechanism of action of tolazoline in neonatal hypoxemia

SummaryThe effect of tolazoline was assessed in 29 hypoxic neonates. Tolazoline was given in a bolus starting at 1 mg/kg and repeated or infused for 5–134 hours. A “good clinical response,” defined as a rise in Pao2 of more than 20 mm Hg, was obtained in 23 (79%), 20 of this group were weaned from the respirator, and three died. Six infants did not respond initially and four died. Failure to respond to tolazoline or to be weaned from the ventilator was usually associated with severe additional pathology.Urine output (>1 ml/kg/h) was adequate in most neonates during therapy. In those with preexisting oliguria (<1 ml/kg/h), output improved during therapy. Blood pressure monitoring showed a fall in blood pressure in 19 patients during tolazoline administration, but true hypotension only occurred in four; in seven there was no fall and in three there was a rise in blood pressure.Echocardiography was performed prior to therapy in 19 patients and repeated in 12 patients after 24 h. Additional “tracking” was performed at 10 min, 1 h, and 4 h in seven patients. Prior to therapy, right ventricular dysfunction was demonstrated by abnormal right ventricular systolic time intervals (RVSTIs) in 17 of the patients tested. A rapid improvement was evident during therapy especially with “tracking.” Left ventricular dysfunction, assessed by left ventricular systolic time intervals (LVSTIs), ejection fraction (EF), shortening fraction (SF), and velocity of circumferential fiber shortening (VCF), was also evident prior to therapy and improved, though more gradually than the RVSTIs.Tolazoline was therefore effective in neonatal hypoxia and improved cardiac dysfunction. A critical review of side effects and complications showed that (a) oliguria may precede therapy and renal impairment usually diminished, and (b) true hypotension was less of a problem than previously reported. As perfusion depends directly on blood pressure and inversely on vascular resistance, the systemic effect of tolazoline was to improve perfusion as a consequence of the fall in vascular resistance which improved ventricular function. We wish to introduce the hypothesis that afterload reduction is an additional therapeutic mechanism of tolazoline in neonatal hypoxemia.

Aortico-left ventricular tunnel associated with critical aortic stenosis in the newborn

SummaryAortico-left ventricular tunnel is a rare congenital malformation. A unique case of critical aortic stenosis in a neonate accompanying aortico-left ventricular tunnel is described. Successful surgical correction was performed without invasive studies following echocardiographic recognition of the defect.