Minimally invasive management of transposition of the great arteries in the newborn period.

This study reports on a predominantly noninvasive management program for neonatal transposition of the great arteries [TGA] incorporating balloon atrial septostomy [BAS] under echocardiographic control. BAS was performed in 25 consecutive patients presenting with TGA between April 1988 and April 1990. Structural and coronary anatomy was evaluated echocardiographically with angiographic supplementation only when additional data were required. This information was correlated, where possible, with direct anatomic findings and subsequent course. BAS was performed through the umbilicus in 17 patients (85% of patients in whom this approach was attempted). Thirteen patients did not require ventilation during BAS. There were minimal complications and satisfactory septostomies in all cases. Coronary anatomy was correctly predicted in all patients where anatomic correlation was available. Without invasive investigation 9 patients underwent neonatal arterial switch procedures and 2 underwent palliative procedures. BAS under echocardiographic control proved safe, effective, minimally traumatic and mostly possible via the umbilical vein. The umbilical vein, where patent, permitted rapid safe access for BAS. Echocardiographic diagnosis of the coronary artery, and structural and functional anatomy was reliable and allowed minimally invasive preoperative management in many patients.

Myocardial infarction in childhood: clinical analysis of 17 cases and medium term follow up of survivors.

Between 1979 and 1989 17 patients aged two months to 12 years with acute myocardial infarction of any cause (other than after cardiac surgery) were seen at a children's hospital. Eight died from three days to three years after diagnosis (overall mortality 47%). The nine survivors, now aged 2-17 years, have been followed for one to 10 years (mean follow up five years) after infarction. The commonest causes of myocardial infarction in this series were anomalous origin of left coronary artery from the pulmonary artery (six patients (35%] and Kawasaki disease (five patients (27%]. The main symptoms of acute myocardial infarction were dyspnoea, vomiting, and difficulty feeding. Diagnosis was made in all patients by electrocardiography and confirmed by echocardiography, cardiac catheterisation, or at operation. All survivors were symptom free with excellent exercise capacity. The left ventricular ejection fraction in survivors ranged from 21% to 66%, and only one child was on regular cardiac medications. There were no cases of late sudden death. Twenty four hour Holter monitoring performed on survivors was normal (seven) or showed minor abnormalities only (one), suggesting that serious arrhythmia is rare after paediatric myocardial infarction. Myocardial infarction in children had a high early mortality; however, the incidence of serious arrhythmia was low in the survivors, who had a good exercise tolerance even when the left ventricular ejection fraction was low.

Nitroprusside in children after cardiopulmonary bypass: a study of thiocyanate toxicity.

Thiocyanate levels, an indicator of nitroprusside toxicity, were studied in 22 children after repair of structural heart disease during cardiopulmonary bypass. At the total dose (2.6 +/- 2.3 mg/kg) and time (34.4 +/- 19 h) ranges of this study, no evidence of toxicity was detected, despite this total dose exceeding recommended maximum in some patients. Nitroprusside infusion, as described, in children with normal hepatic and renal function is safe and may not warrant routine assessment of thiocyanate levels.

The surgical management of aortopulmonary window using the anterior sandwich patch closure technique.

Between 1969 and June, 1986, 13 patients with aortopulmonary window were evaluated and operated upon with eleven survivors. All were children with ages ranging from 2 weeks to 2 1/2 years and had a typical aortopulmonary window (Type 1) with a connection between the ascending aorta and main pulmonary artery. Six of them also had associated cardiac anomalies. Operative techniques included both closed and open procedures. Simple ligation was carried out in two, while the remaining 11 patients were operated upon with the aid of extracorporeal circulation. "Sandwich" patch closure was the preferred method which was employed in 7 patients.

Echo Doppler assessment of cardiac output and its relation to growth in normal infants.

In a study of 38 normal infants, serial measurements of systemic (n = 169) and pulmonary (n = 143) blood flow were undertaken from the ages of 2 weeks to 12 months by 2-dimensional, M-mode and pulsed Doppler echocardiography. Cardiac output changed linearly (cardiac output = 0.3 X height -0.99 liter/min), and cardiac index was validated as a means for standardizing cardiac output in infants younger than 10 to 13 months of age. Infants younger than 2 months had lower cardiac indexes and stroke volume indexes (2.6 +/- 0.7 liters/min/m2 and 19 +/- 5 ml/m2, respectively) compared with those aged 12 months (3.2 +/- 0.7 liter/min/m2 and 25 +/- 5 ml/m2, respectively). Changes in cardiac output in individual infants over time suggest nonmorphometric modulating factors for cardiovascular function.

Cardiac surgery in the first year of life: the effect on weight gains of infants with congenital heart disease.

Forty-seven infants with ventricular septal defect (n = 17), tetralogy of Fallot (n = 7) and transposition of the great arteries (n = 23) who had 'corrective' surgery in the first year of life were reviewed with respect to birthweight and pre- and postoperative growth. The mean birthweight for each group was below that of the standard population. There was an overall decrease in growth velocity pre-operatively which was reversed after surgery. At follow up, 12-18 months later (means), most infants had regained at least their birthweight percentile, while the group with ventricular septal defect exceeded it. Consideration is given to the pathophysiological mechanisms contributing to these observations.

Accessory mitral valve tissue causing left ventricular outflow tract obstruction.

Although left ventricular outflow tract obstruction is commonly associated with congenitally corrected transposition of the great vessels, this obstruction is seldom caused by accessory mitral valve tissue. Three cases in which accessory mitral valve tissue caused left ventricular outflow tract obstruction in children are described. Two had congenitally corrected transposition and one had normally connected great vessels. The accessory leaflet tissue, which was identified by echocardiography and angiography, was attached by chordae tendineae to normally sited papillary muscles and herniated into the left ventricular outflow tract during systole. Operation was successful in these patients. The accessory valve tissue was excised via an arteriotomy in the great vessel that arose from the left ventricle. The obstructive tissue was excised close to its peripheral attachments in the outflow tract and its chordae tendineae were divided. Resection was performed without injury to the abnormally placed conduction system or to the normal valve structures.

Fetal echocardiography: experience and reason.

Improvements in echocardiographic techniques have allowed detailed study of the fetal heart by experienced paediatric echocardiographers. We report 40 studies in 36 fetuses from 18 to 38 weeks' gestation whose mothers were referred for the assessment of fetal hydrops or arrhythmia or because of a family history of congenital heart disease. Normal, or probably normal, cardiac structure was demonstrated in 29 studies and abnormal, or probably abnormal, structure in seven. In four studies the imaging was inadequate and an opinion was deferred until further study. In this series, the sensitivity and specificity of the technique was 100% and 95% respectively. Fetal echocardiography is useful in pregnancies at high risk of fetal heart disease and for the further study of developmental cardiology. The results of such studies include the optimal management of pregnancy and delivery of high-risk neonates, and the allaying of parental anxiety.

Infective endocarditis in childhood.

A total of 37 cases of infective endocarditis, in children aged two days to 13 years, were seen from 1971 to 1983 at the Children's Hospital, Camperdown. Structural heart disease was known to preexist in 95%. Cyanotic congenital heart disease was present in 15 children, of whom 11 had been palliated by a systemic-to-pulmonary artery shunt. In five children, there was infection of a prosthetic valve. Identifiable precipitants of infection were rare. In particular, no child had had a preceding dental procedure within three months, while only 19% had had recent cardiac surgery. Organisms were identified by blood culture in 92%, the majority being streptococci (43% of cases) and staphylococci (27% of cases). While 59% of all organisms were penicillin sensitive, six of the seven early postoperative children were infected with organisms not sensitive to antibiotics, given for wound infection prophylaxis in the perioperative period. The overall death rate was 13.5%. Of the children infected with Staphylococcus aureus, 40% died, while no child with Streptococcus viridans endocarditis died. Of the survivors, four needed urgent valve replacement, and three had major central nervous system complications. Using these figures, a current profile of patients with infective endocarditis is presented.

Generalized arterial calcification of infancy: three case reports, including spontaneous regression with long-term survival.

Generalized arterial calcification in infancy is a rare disorder in which death usually occurs in infancy, the diagnosis generally being made at autopsy. Three patients are reported. The diagnosis was made during life in two, enabling new information to be collected. Cardiac catheterization in one provided evidence suggesting stiffness of pulmonary and systemic arterial walls. Another is a long-term survivor with spontaneous regression of calcification. The third case, diagnosed at necropsy, was associated with endocardial fibroelastosis.

Cardiovascular manifestations of Kawasaki disease in an Australian population.

Over a three-year period, 30 children were admitted to the Royal Alexandra Hospital for Children, Sydney, with a diagnosis of Kawasaki disease. Of these, 26 children underwent echocardiography which demonstrated coronary artery aneurysms in five. Angiography was performed in one patient whose aneurysm did not resolve spontaneously. No patient suffered significant morbidity, and none died.

Prophylaxis of bacterial endocarditis. Awareness of need.

The parents or guardians of attenders at a paediatric cardiac clinic were surveyed over five months. Ninety-six patients who were at risk of bacterial endocarditis were identified. In 46% of these, the parents or guardians had insufficient knowledge to ensure that their children will receive prophylaxis at times of risk. A first language other than English, a lower level of education of the main family wage- earner , lack of exposure to previous dental extractions and non-cardiac operations, and a child aged less than five years--all correlated with poor knowledge of prophylaxis. Means of achieving greater awareness of need and efficacy of protection are suggested.

Intravenous verapamil in the treatment of paroxysmal supraventricular tachycardia in children.

Fifty-four spontaneous episodes of paroxysmal supraventricular tachycardia (PSVT) in 23 patients, varying in age from one day to fourteen years, were treated with intravenous verapamil according to a specific protocol. Stable sinus rhythm was obtained promptly with no side effects in 76% of episodes. There was no response in 9%; an unstable rhythm in 7.5%; and severe side effects (hypotension, sinus bradycardia and cardio-respiratory arrest) in 7.5%. All severe side effects were associated with larger than recommended doses of verapamil. Intravenous verapamil reverted 100% of all episodes of idiopathic PSVT in eight patients; 83% of episodes in five patients with congenital heart disease; and only 57% of episodes in nine patients with Wolff-Parkinson-White syndrome. It was ineffective in one neonate who had had intra-uterine SVT.

Profound hypothermia with circulatory arrest: nine years' clinical experience.

A total of 550 intracardiac operations were performed with the aid of profound hypothermia and circulatory arrest between March, 1971, and December, 1979. Both cooling and rewarming were effected by means of an extracorporeal heat exchanger. Overall mortality was 20%, falling to 10% in 1979. Highest risks were associated with operations in the neonatal period and for unusually complex defects. The technique has proved safe for straight forward corrections in young age groups and is especially valuable for selected complex lesions in older children and those requiring reoperation. Although circulatory arrest has greatly extended the range of corrective heart operation in infancy, we believe there is still a significant place for palliative procedures in appropriate circumstances. Neurologic complications attributed to the technique have been uncommon, and only 4.5% of the survivors have any recognizable residual neurologic lesion, whether coincidental or resulting from circulatory arrest. The technique is simple, reliable, and generally safe.

Trans--pulmonary arterial repair of supracristal ventricular septal defects in infancy.

Five patients aged 2 months to 2 years with isolated large supracristal ventricular septal defect (VDS) and severe pulmonary hypertension had corrective operation between April, 1978, and November, 1979, performed via a trans--pulmonary arterial approach. This technique provided excellent exposure for accurate placement of sutures, especially between the two semilunar valves. All patients are well, with no residual defects, and their postoperative electrocardiograms (ECGs) do not show any intraventricular conduction abnormality. The technique is especially useful in the presence of severe pulmonary hypertension, wherein ventriculotomy is best avoided and the dilated main pulmonary artery offers excellent access.

Angiographic assessment of anomalous origin of the left coronary from the pulmonary artery in infancy and childhood.

Angiographic findings in five paediatric patients with anomalous left coronary artery arising from the pulmonary artery are presented. An attempt is made to provide an angiographic rationale of some aspects of the pathophysiology and electrocardiography in this condition, and the vital importance of angiography in selecting the appropriate surgical approach is underlined.