Transposition of the great arteries: operative outcome in the current era.

AIMS: To assess the operative outcome, cardiac and neurodevelopmental sequelae in infants with transposition of the great arteries (TGA) undergoing the arterial switch operation (ASO). METHOD: Cross-sectional review of the 48 consecutive patients operated on in the calendar years 1995 and 1996 was undertaken to obtain recent cardiac, growth and neurodevelopmental parameters, and the mortality results were compared to the entire cohort of infants who underwent the ASO for definitive repair of TGA and double outlet right ventricle at Greenlane hospital between 1984 and 1998. RESULTS: Between January 1995 and December 1996, 48 patients underwent the ASO. 96% were alive, and 88% alive and free from reoperation or significant neurological sequelae at a mean followup interval of sixteen months. Six (13%) had important residual cardiac lesions, of which supra valvular pulmonary stenosis was the most common. Growth parameters at follow-up were normal, as was the neurodevelopmental progress of all but two survivors (96%). CONCLUSION: In the current era, the ASO is a relatively safe procedure with excellent cardiac and neurodevelopmental outcome in the majority of infants.

Long-term outcome after the mustard repair for simple transposition of the great arteries. 28-year follow-up.

OBJECTIVES: This study examines the late outcome in patients with simple transposition of the great arteries (TGA) after a Mustard operation. BACKGROUND: Continuing medical follow-up for patients after the Mustard procedure, now extending to three decades, is required. The quality of life of adult survivors has not been well documented. METHODS: Survival and quality of life among 113 hospital survivors of the Mustard operation performed for simple TGA between 1964 and 1982 were assessed by medical review and a lifestyle questionnaire. The incidence of right ventricular failure and echocardiographic right ventricular dysfunction (RVD) were determined. A measure of lifestyle, the ability index, was determined. RESULTS: Actuarial survival was 90%, 80%, and 80% at 10, 20, and 28 years, respectively, with 76% of survivors being New York Heart Association class 1. Sudden death, with an incidence of 7% without identifiable risk factors, was the most common cause of late demise. RVD was identified in 18% of patients who had echocardiography, but there was right ventricular failure in only two patients. Seventy-five percent of current survivors lead a normal life, 20% have some symptoms or lifestyle modification, and 5% are unable to work. CONCLUSIONS: The survival of patients to 28 years with the Mustard repair has been good. Late sudden death is the most worrisome feature. There is a 97% freedom from right ventricular failure to date. The quality of life of late survivors is good, most achieving a normal level of education and employment.

Outcome of pregnancy after the Mustard operation for transposition of the great arteries with intact ventricular septum.

OBJECTIVES: This study examined the outcome of pregnancy in patients with transposition of the great arteries and an intact ventricular septum after a Mustard operation. BACKGROUND: Before the introduction of surgical treatment, most children with transposition of the great arteries died in early infancy. A number of these patients have now reached their reproductive years. There is little information about the effect of pregnancy on cardiovascular status, particularly the ability of the right ventricle to adjust to the hemodynamic changes of pregnancy. The outcome for the offspring and their risk of congenital heart disease are also unknown. METHODS: Twenty-three female late survivors after the Mustard operation > 15 years of age were reviewed in relation to the occurrence of pregnancy and its outcome. Serial echocardiographic estimates of right ventricular volume during pregnancy were made in three local patients. RESULTS: Nine women had 15 pregnancies. They were asymptomatic before pregnancy and remained free from cardiac symptoms during each pregnancy. Right ventricular volume in the three patients studied increased during pregnancy but returned to normal at 8 to 11 weeks postpartum. There were 12 live births, 2 spontaneous abortions and 1 intrauterine death. None of the liveborn infants had evidence of congenital heart disease. CONCLUSIONS: In this small group of women with good quality late survival after a Mustard operation, pregnancy was well tolerated. We suspect that the incidence of congenital heart disease in infants of mothers with transposition of the great arteries will be at the lower end of the range for mothers with different types of congenital heart disease, but further data will be needed to confirm this.

One year audit of a referral fetal echocardiography service.

AIM: To perform a one year audit of a referral fetal echocardiography service. METHODS: In 1992, 132 fetuses were referred for two dimensional fetal echocardiography, 40% being less than 24 weeks gestation. Validation of the accuracy of the fetal diagnosis by postnatal clinical or appropriate cardiac investigation was undertaken. RESULTS: Indications for referral were a family history of congenital heart disease (n = 36), maternal indications, (40) suspected congenital heart disease on obstetric scan, (21) noncardiac fetal abnormality (19) and fetal arrhythmia. (16) The fetal echocardiogram was normal in 112, abnormal in 18 and not technically possible in two. The negative prediction of congenital heart disease was 96% accurate with four cases of congenital heart disease not diagnosed in utero. The positive prediction of congenital heart disease was 93% accurate with one false positive of a ventricular septal defect. The overall incidence of congenital heart disease was 17%. Four of 14 fetuses with major congenital heart disease had a chromosomal abnormality and five a coexistent noncardiac abnormality. The outcome of these 14 fetuses was poor, with three stillbirths, one termination of pregnancy, seven neonatal deaths and three only surviving beyond the neonatal period. Eleven of 21 cases referred with suspected congenital heart disease on obstetric scan were abnormal. CONCLUSION: Detailed fetal echocardiography can predict significant congenital heart disease with a high degree of accuracy. Suspected cardiac abnormality on obstetric scans warrants referral for detailed fetal echocardiography, as do those considered at increased risk of congenital heart disease.

Efficacy and dosage of enalapril in congenital and acquired heart disease.

In a tertiary referral centre 63 patients underwent 67 treatment periods with enalapril. The median age was 5.4 months. All children had signs of heart failure: congestive cardiac failure with breathlessness at rest was present in 88%. Haemodynamic groups were left-to-right shunt (n = 15), impaired ventricular function (n = 14), after cardiac surgery (n = 23), valvar regurgitation (n = 12), and hypertension (n = 3). Serial clinical, radiological, and laboratory data were used to judge outcome. The mean (SD) maximal dose was 0.30 (0.21) mg/kg/day. Thirty nine (58%) patients improved, 20 (30%) showed no improvement, and eight (12%) had side effects requiring discontinuation of enalapril. Renal failure in eight patients was related to young age, low weight, and left-to-right shunt group. Three patients died in congestive heart failure with renal failure. Enalapril was clinically safe and effective for children with cardiac failure secondary to ventricular impairment, valvar regurgitation, or after cardiac surgery. Renal failure was a problem in young infants with left-to-right shunts.

Transcatheter closure of patent ductus arteriosus in children and adults.

AIM: To describe the initial New Zealand experience of transcatheter patent ductus arteriosus closure in adults and children. METHODS: Twenty-three children beyond infancy and four adults with isolated patent ductus arteriosus were selected for transcatheter umbrella closure. Rashkind umbrellas were placed across the patent ductus arteriosus through a percutaneously inserted long venous sheath using the Mullins technique. RESULTS: In 25 of the 27 patients a Rashkind umbrella was placed accurately. In two patients the umbrella could not be placed accurately: in one the procedure was abandoned uneventfully and in one the umbrella embolised to the right pulmonary artery necessitating surgical removal of the device and patent ductus arteriosus closure. There were no other significant complications. A second umbrella insertion is planned in two children for a significant residual leak at 1-year follow up. CONCLUSIONS: Transcatheter patent ductus arteriosus closure is a low risk and usually effective alternative to surgical closure for the majority of patients beyond infancy.

Percutaneous balloon angioplasty for early postoperative modified Blalock-Taussig shunt failure.

Percutaneous balloon angioplasty was successful initial treatment for 2 infants who, early after operation, developed obstruction at the proximal anastomotic site of a modified Blalock-Taussig shunt. Two years later the first child had not required reoperation and the dilatation site was patent angiographically. The other baby progressed well after angioplasty but because of surgical concern about the long-term success of angioplasty, shunt surgery was repeated, the baby dying after reoperation. Angioplasty of proximal obstruction in these shunts is feasible and satisfactory long-term palliation can be achieved avoiding repeat shunt surgery before the more definitive Fontan-type procedure.

Acute hemodynamic effects of converting enzyme inhibition in children with intracardiac shunts.

The short-term hemodynamic effects of intravenous enalaprilat were assessed in 26 infants and children, aged 6 months to 15 years, with intracardiac shunts undergoing cardiac catheterization. Pulmonary and systemic pressure, flow, and resistance indices were measured by the direct Fick method before and 30 min after enalaprilat at 0.06 mg/kg. Aortic and pulmonary artery pressure decreased 15 and 20%, respectively, by 10 min, with little further change at 30 min. The heart rate did not change significantly and there was no reduction in systemic flow. In those with a large ventricular septal defect and normal or near-normal pulmonary resistance (less than 3.5 u.m2, n = 8), the mean pulmonary-systemic flow ratio decreased from 2.9 +/- 0.3 to 2.4 +/- 0.3 (p less than 0.05) and the mean left-to-right shunt from 7.4 +/- 0.8 to 5.9 +/- 0.7 L/min/m2 (p less than 0.02). Those with an elevated pulmonary vascular resistance (greater than 5 u.m2, n = 8) showed a varied response. Two children, both with Down's syndrome, an atrioventricular canal defect, and reversible pulmonary hypertension (as assessed by an infusion of isoproterenol), had no decrease in pulmonary vascular resistance with enalaprilat. There were no adverse effects. Converting enzyme inhibitors may benefit "heart failure" associated with large ventricular septal defects and normal or mildly elevated pulmonary resistance.

Stenosis of pulmonary veins in Down syndrome.

Two patients with Down syndrome, intracardiac communications and elevated pulmonary arteriolar resistance presented early in life. Both patients had significant stenosis of pulmonary veins. The progressive nature of the stenosis is illustrated in one patient. Pulmonary venous stenosis in Down syndrome has been recorded only twice before in the literature, and may play a part in the early onset of pulmonary vascular occlusive disease in some patients.

Predictors of long-term survival with Ebstein's anomaly of the tricuspid valve.

In patients with Ebstein's anomaly of the tricuspid valve, predictors of death and indications for surgery are poorly defined. We retrospectively reviewed 48 patients with Ebstein's anomaly, 17 (35%) of whom presented in the first week of life. Duration of follow-up extended to 32 years (greater than 10 years in 35%). Twenty of the 48 patients (42%) died, 6 in the first week of life and 1 at age 5 months. Thirteen of the 41 patients surviving to age 6 months subsequently died, 50% probability of survival being reached at 47 years. Significant (p less than or equal to 0.05) predictors of death in this group were: male sex, cardiothoracic ratio greater than or equal to 0.65, New York Heart Association class III or IV, breathlessness and the absence of Wolff-Parkinson-White syndrome. Eight patients died suddenly. A cardiothoracic ratio greater than or equal to 0.65 was a better predictor of sudden death than functional status. All who developed atrial fibrillation died within 5 years. Other atrial arrhythmias were not helpful in predicting sudden death. In view of these findings, tricuspid valve surgery is recommended before the cardiothoracic ratio reaches 0.65, regardless of the symptomatic state.

Effects of prostaglandin E1 given in low doses on the histopathology of the arterial duct.

The histopathology of the arterial duct was studied in relation to the maximal infusion rate of prostaglandin E1 administered in 35 infants with congenital heart disease. Two groups were distinguished based on the maximal infusion rate. The group receiving prostaglandin at low dose received 0.01 to 0.05 micrograms/kg/min (16 cases), the group having a high dose received greater than 0.05 to 0.7 micrograms/kg/min (19 cases). The histopathology was compared between the groups. Ductal damage was less common in the cases receiving a low rate of infusion than in those having a high rate of infusion. Multivariate analysis showed no relation between ductal pathology and the age of onset or duration of treatment, nor on the total dose of prostaglandin E1. Histological abnormalities were more common in patients with a gestational age equal to or greater than 40 weeks. Ductal damage was less common in patients with pulmonary atresia or stenosis compared with other anatomic diagnoses. Low dose infusions are recommended for treatment with prostaglandin E1 in infants with congenital heart disease.

Progress of patients with pulmonary atresia after systemic to pulmonary arterial shunts.

Between February 1980 and June 1987, 42 shunts were placed in 39 infants with pulmonary atresia: 33 were modified Blalock-Taussig shunts with polytetrafluoroethylene (PTFE) and 9 were classic Blalock-Taussig shunts. There were four hospital deaths not related to the shunts. The remaining 35 patients were followed up for 1.6 months to 6.3 years (mean, 24.7 +/- 18 months). Repeat cineangiocardiographic studies revealed stenosis or distortion of the pulmonary arteries related to the site of the shunt in 11/22 patients (50%) with PTFE shunts and in 1/6 (17%) with classic Blalock-Taussig shunts; the stenosis was severe in only 1 patient. Mean increase in the pulmonary arterial index in the group with classic Blalock-Taussig shunts was 117 +/- 52 mm2/m2 (not significant) and in the group with PTFE shunts, 158 +/- 21 mm2/m2 (p less than 0.001). Late shunt occlusion occurred in 1 patient 23 months postoperatively. Thereafter, shunt patency rate remained at 94% +/- 6%. At the end of 1 year 81% +/- 7% of patients were judged to have adequate palliation, but between 2 and 3 years, only 60% +/- 10%. Univariate analysis showed that after 2 years the ranking order for successful palliation was classic Blalock-Taussig, 5-mm PTFE, and 4-mm PTFE shunts, but differences did not achieve statistical significance.

Assessment and follow-up of patients with ventricular septal defect and elevated pulmonary vascular resistance.

Cardiac catheterization was undertaken in 87 patients (for a total of 89 studies) with ventricular septal defects, including 58 patients with moderate or severe elevation of pulmonary arteriolar resistance. When resting resistance was less than or equal to 7.9 U . m2, it always decreased with isoproterenol and no postoperative problems were experienced with pulmonary vascular obstructive disease. In 36 patients resting resistance measured greater than or equal to 8 U . m2. In 17 of these patients it decreased to less than 7 U . m2 with isoproterenol. Fifteen patients were operated on and postoperative problems with pulmonary vascular disease were experienced only in the single patient whose repair broke down. Surgery was undertaken in 4 of 19 patients in whom resistance did not decrease to less than 7 U . m2 with isoproterenol and advanced pulmonary vascular disease was evident in the 3 patients with follow-up observation. Correlation between measured resistance and other hemodynamic parameters was only fair. A pulmonary to systemic resistance ratio greater than or equal to 0.75 always indicated high absolute resistance but resistance ratios less than 0.75 were found quite frequently in the group with limited response to isoproterenol. These data argue that a reliable estimate of resistance, less than 7 U . m2, with a vasodilator predicts a good postoperative response regardless of measurements at rest or other hemodynamic parameters. Although observations on postoperative progress of patients with resistance greater than 7 U . m2 with a vasodilator are limited, a good postoperative course is unlikely unless resistance can be lowered to a level close to 7 U . m2.

Coronary arterial abnormalities in pulmonary atresia with intact ventricular septum.

The incidence and severity of abnormalities of the coronary arteries were evaluated in 35 necropsy patients with pulmonary atresia and an intact ventricular septum. Right ventricular to coronary artery fistulous connections were found in more than 60% of the cases. All patients with fistulous connections had histologic abnormalities of the coronary arteries. In 50% the lesions were mild, with medial and intimal thickening producing up to moderate luminal stenosis. In 50% there was loss of normal arterial wall structure and severe narrowing or obliteration of the arterial lumen. The coronary arterial fistulas and histologic abnormalities were prevalent in those with underdevelopment of the tricuspid valve and right ventricular cavity but were not found in patients with a normal or dilated tricuspid valve anulus. The coronary arterial abnormalities were found in more than 80% of patients with a tricuspid valve/mitral valve ratio less than 1. A single coronary artery occurred in 6 patients (17%) of this series. In 80% of those with 1 coronary artery arising from the other, the aberrantly arising coronary artery crossed anteriorly to the pulmonary artery and could be at risk in surgical attempts to reconstruct the right ventricular outflow. Aortography is recommended if the coronary arteries are not clearly delineated on ventricular cineangiocardiography.

Anatomical and echocardiographic correlations in the normal heart.

Knowledge of the normal intracardiac structures and their variations is essential for interpretation of two-dimensional echocardiography. The anatomical features seen in the standard echocardiographic views have been demonstrated in normal heart specimens. The cardiac chambers and their connections must be identified. Visualisation of the inferior vena caval drainage to the right atrium usually enables its identification. The right ventricle may be distinguished by the more distal attachment of the tricuspid valve compared to the mitral valve and the presence of the moderator band. The pulmonary artery is recognised by its bifurcation, whereas visualisation of the origin of the brachiocephalic arteries or of both coronary arteries from a great artery identifies the aorta. Anatomical variants such as a prominent Eustachian valve of the inferior vena cava in the right atrium and fibromuscular strands or 'heart strings' traversing the left ventricular cavity are frequently visualised on the two-dimensional echocardiograms.

Pathology of the ductus arteriosus treated with prostaglandins: comparisons with untreated cases.

Our histological study of the ductus arteriosus compared 12 infants who were treated with E-type prostaglandins with 12 control infants matched as closely as possible for age and diagnosis. Distinguishing histological features were seen in five of the treated cases and in none of the untreated cases. These features were intimal tears in two and hemorrhage into the media in five. Medial edema, mural thrombosis, and interruption of the internal elastic lamina at sites not beneath intimal cushions occurred both in treated and untreated infants and therefore were not distinguishing features. The gross anatomical features of the ductus arteriosus were assessed in these 24 and in another 85 cases. Significant differences in the ductus arteriosus were noted between cases with pulmonary atresia or aortic atresia and normals, but not between those treated with E-type prostaglandins and controls.

Variant of tetralogy of fallot with absent pulmonary valve leaflets and origin of one pulmonary artery from the ascending aorta.

Absent pulmonary valve leaflets and anomalous origin of a pulmonary artery from the ascending aorta have been reported as separate lesions associated with tetralogy of Fallot but not in combination. The clinical, radiologic and pathologic findings are presented in three patients with this previously undescribed combination. A search of the literature for similar cases revealed 233 patients with absent pulmonary valve leaflets and 56 patients with anomalous origin of a pulmonary artery from the ascending aorta; these cases are reviewed. Although 17 patients with absent pulmonary valve leaflets and tetralogy of Fallot also had absence of the proximal portion of the left pulmonary artery, none had an anomalously arising pulmonary artery from the ascending aorta. In the reviewed cases, anomalous origin of the right pulmonary artery from the ascending aorta was more frequent than that of the left pulmonary artery (44 compared with 12 cases, respectively), but the latter was more often associated with tetralogy of Fallot.

Postoperative evaluation of patients with tetralogy of Fallot repaired in infancy. Including criteria for use of outflow patching and radiologic assessment of pulmonary regurgitation.

The late hemodynamic and radiologic findings were good or excellent in 96 percent of 23 infants in whom tetralogy of Fallot was repaired with the use of profound hypothermia. These results encourage continuation of the policy of early repair rather than palliation in tetralogy of Fallot. The preoperative cineangiocardiographic assessment of the type and severity of the pulmonary stenosis accurately predicted the findings at operation and the type of repair required. In infants between 1 and 21 months of age and 3 and 10 kilograms in weight, a main pulmonary artery (MPA) diameter of less than 7 mm. was the cineangiocardiographic measurement most accurately predicting the necessity for an outflow patch across the pulmonary ring. Postoperative studies showed significant increases in the MPA and pulmonary ring diameters. A Method of cineangiocardiographic assessment of pulmonary incompetence is presented. Severe mechanical pulmonary incompetence in some patients produced mild hemodynamic effects by radiologic criteria.