Role of ischemia and infarction in late right ventricular dysfunction after atrial repair of transposition of the great arteries.

OBJECTIVES: This study was conducted to assess whether myocardial ischemia and/or infarction are involved in the pathogenesis of late right ventricular dysfunction in adult survivors of atrial baffle repair for transposition of the great arteries in infancy. BACKGROUND: The medium-term success of intraatrial baffle repair for transposition of the great arteries is good, with many patients surviving into adult life, but prognosis can be limited by progressive right ventricular dysfunction. We hypothesized that ongoing myocardial ischemia and/or infarction are important factors in the pathogenesis of this complication. Radionuclide techniques offer an opportunity to study both myocardial perfusion and concomitant ventricular wall motion. METHODS: Dipyridamole sestamibi single-photon emission computed tomography followed by rest sestamibi single-photon emission computed tomography was used to assess right ventricular myocardial perfusion, wall motion, wall thickening and ejection fraction in 22 adolescents/young adults who had undergone atrial baffle repair for simple transposition of the great arteries at median 6.7 (range 0.5 to 54) months of age. The patients were aged 10 to 25 (median 15.5) years; 19 in New York Heart Association class I, 2 in class II and 1 in class III. All were in a regular cardiac rhythm during the studies. The right ventricular tomographic images were examined in three parallel and two orthogonal planes, analyzed in 12 segments. RESULTS: Perfusion defects were evident in all patients in at least one segment, in either the rest or stress images. Twelve patients (55%) demonstrated fixed defects only, nine (41%) had fixed and reversible defects and one (4.5%) had reversible defects only. Concomitant wall-thickening abnormalities occurred in 83% of segments with fixed perfusion defects, mirrored by a reduction in wall motion in 91% of segments analyzed. Right ventricular ejection fraction was correlated with age (R = 0.62; p = 0.002), and with wall-thickening abnormalities (R = 0.60; p < 0.005). CONCLUSIONS: Reversible and fixed perfusion defects with concordant regional wall motion abnormalities occur in the right (systemic) ventricle 10 to 20 years after Mustard repair for transposition of the great arteries; this may be important in the pathogenesis of late right ventricular dysfunction in this group.

Transcaval repair of the sinus venosus syndrome.

BACKGROUND: Surgical correction of the sinus venosus syndrome has been associated with sinus node dysfunction and venous obstruction postoperatively. We present the long-term follow-up of a lateral transcaval approach, which closes the atrial communication and corrects the partial anomalous pulmonary venous connection to the superior vena cava with the use of a simple pericardial patch. METHODS: The records of 66 patients undergoing repair between April 1981 and April 1997 were examined. Mean age at repair was 10.2 years (range, 1.5-65 years; median, 5 years). Six patients had a left superior vena cava, 4 had an additional atrial septal defect, and 2 had coronary artery bypass grafts. Immediate and long-term follow-up included physical examination, electrocardiography, transthoracic echocardiography, and use of a 24-hour ambulatory Holter monitor. Sinus node function, incidence of significant arrhythmia, and evidence of mechanical venous obstruction were assessed. RESULTS: Follow-up data were available for 64 (97%) patients for a mean follow-up of 4.1 years (range, 1-9 years). There were no deaths. No evidence of residual atrial septal defect, superior vena cava, or venous obstruction were found by echocardiography. On electrocardiography all patients were in sinus rhythm, with no arrhythmia seen. Holter monitoring was performed at a mean of 7.3 years postoperatively. All patients had normal sinus node function, and no sustained atrial arrhythmia was seen. CONCLUSION: Transcaval repair is a simple technique that does not interfere with sinus node function. There is no evidence to suggest that this approach leads to venous obstruction.

Ventricular assist devices in pediatric cardiac surgery.

BACKGROUND: Early experience in other centers with pediatric assist devices has been favorable. METHODS: Prospectively we examined our first 13 patients between January 1992 and September 1994. RESULTS: Thirteen children underwent ventricular assistance at Royal Alexandra Hospital for Children. Age ranged from 4 days to 30 months, weight from 2.9 kg to 17 kg. Ventricular assistance was employed from 1.5 hours to 190 hours. Of 12 surgical patients, 8 required left ventricular assistance to be weaned from cardiopulmonary bypass after correction of congenital defects, and 4 required support in the postoperative period for refractory low cardiac output. A child was supported after a kick to the chest by a horse caused cardiogenic shock. All 13 patients initially responded to ventricular assistance and 7 remain alive. Of the deaths, 2 were neurologic, 2 due to myocardial failure, and 2 to sepsis. The major complications in the first days were hemorrhage and tamponade. Later problems included thrombosis of the circuit despite systemic heparinization, and a cannula-related tear to the anterior mitral leaflet. The 7 survivors are well after 3 to 32 months. CONCLUSIONS: Despite the mortality and complications, we are encouraged by these results, in the light of almost certain death for all 13 patients without ventricular assistance.

The relationship between intelligence and duration of circulatory arrest with deep hypothermia.

A total of 114 children (51 with tetralogy of Fallot, 30 with transposition of the great arteries, and 33 with ventricular septal defect) who had these defects repaired with the use of deep hypothermia and circulatory arrest were assessed for intellectual and neuropsychologic function at an average of 9 to 10 years after the operation. Children with preoperative intellectual handicaps or postoperative neurologic complications were excluded. These children were compared with 54 who had atrial septal defects repaired with the use of cardiopulmonary bypass. The only significant difference in the neuropsychologic measures was that the bypass group had reaction times 2 to 3 seconds shorter on average than those of the hypothermic circulatory arrest group. Although there was no significant difference in intelligence quotient between the groups, a relationship between intelligence quotient and arrest time was found. Regression analysis of intelligence quotient against duration of arrest showed a significant decrease in intelligence quotient with increasing arrest time (slope = -0.36; p = 0.002; 95% confidence interval, -0.59, -0.14) indicating a decrease of 3 to 4 intelligence quotient points for each extra 10 minutes of arrest time. It appears that deep hypothermia with circulatory arrest for cardiac operations in children does not fully protect the brain, with a linear relationship existing between the amount of impairment and the duration of circulatory arrest.

Intellectual function and age of repair in cyanotic congenital heart disease.

Eighty one children, comprising 51 with tetralogy of Fallot and 30 children with transposition of the great arteries (TGA) were assessed using the Wechsler intelligence scale for children--revised, and a battery of neuropsychological measures. They were compared with a group of 33 children who had surgery for ventricular septal defect. All children were aged over 10 years when reviewed and were in good health, attending normal schools. No significant negative correlation was found between any component or subtest of the IQ scores and operating age. There was no evidence of a detrimental effect of older age at operation in the children who had cyanotic heart disease as assessed by neuropsychological measures. Delaying surgery for children with TGA or tetralogy of Fallot does not appear to adversely affect their intellectual development. This finding may provide reassurance in cases where surgery has to be delayed for medical, social, or economic reasons.

Parent and teacher perceptions of child behaviour following cardiac surgery.

To determine if parents whose children had undergone successful cardiac surgery perceived their children any differently from parents of children who had not undergone surgery, we used the Achenbach Child Behaviour Checklist (CBCL) to compare parent and teacher perceptions in these two groups. Subjects included 168 children who had undergone cardiac surgery 4 to 8 years previously and 51 controls. On the behaviour scale of the CBCL, the teacher's mean t scores showed no significant difference between the cardiac and control groups, in contrast to the parents' scores where parents perceived a higher degree of behavioural problems in children who had undergone cardiac surgery. On the social competence scale of the CBCL, the parents scored their children who had undergone cardiac surgery as less socially competent than did the parents of the controls. Teachers' scores showed no difference between groups.

Amiodarone management of junctional ectopic tachycardia after cardiac surgery in children.

OBJECTIVE: To assess the effectiveness and safety of amiodarone in the treatment of junctional ectopic tachycardia (JET) after open heart surgery in children. PATIENTS: Between January 1990 and December 1991, 16 consecutive patients aged 6 days to 14 years with JET associated with significant haemodynamic impairment after cardiopulmonary bypass were treated with amiodarone as the principal antiarrhythmic drug. INTERVENTIONS: Amiodarone 5 mg/kg was administered intravenously over one hour and the same dose was subsequently infused over 12 hours. This was reviewed every 12 hours and repeated as necessary until a satisfactory heart rate and stable haemodynamics were achieved. Atrial pacing was used whenever possible to provide atrioventricular synchrony. RESULTS: Except for one patient with a JET rate of 160/min, the maximum JET rate ranged from 180/min to 245/min with a mean(SD) of 200 (20)/min. After amiodarone, the heart rates reduced to a mean(SD) of 170 (20), 164 (27), 158 (27), 157 (24), and 153 (19)/min at two, four, eight, 12, and 24 hours respectively. A reduction in tachycardia rate allowing atrial pacing was achieved in 10 patients by two hours. Haemodynamic variables improved in most patients with an increase in mean systolic blood pressure by an average of 15 mm Hg and a decrease in atrial filling pressures by an average of 3.5 mm Hg at four hours after amiodarone administration. There were three deaths: one was a moribund patient who died soon after the onset of JET and the other two deaths were not directly related to JET. COMPLICATIONS: Late bradycardia with hypotension was recorded in one patient. Asymptomatic late sinus bradycardia was seen in several others. CONCLUSIONS: Amiodarone can be used safely and effectively to control JET with haemodynamic improvement in most patients. The addition of atrial pacing confers the advantage of atrioventricular synchrony.

Salvage of infected truncus repair using rifampicin-impregnated gelatin-sealed graft.

An infant suffered sternal infection and ventricular septal patch dehiscence after a truncus arteriosus repair. Successful reoperation used rifampicin-impregnated gelatin-sealed Dacron to repair the recurrent ventricular septal defect and replace the contaminated conduit. This was an effective solution to a potentially lethal surgical complication.

Localized supravalvar aortic stenosis: a new technique for repair.

The deformity in supravalvar aortic stenosis includes generalized thickening of the tissues of the aortic root with a fairly normal sized aortic valve ring. The thickened tissues may obstruct the origins of the left and right coronary arteries. We have repaired 2 cases with complete excision of the stenosing ring below the level of the commissures of the aortic valve into the sinuses, to the level of the left and right coronary arteries.

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.

Report of four cases of aneurysm complicating patch aortoplasty for repair of coarctation of the aorta.

Patch aortoplastry, used almost routinely in the period 1972-86, except in infants in the operative treatment of coarctation of aorta, is sometimes complicated by late formation of true or false aneurysms. This complication, which seems likely to increase with longer follow-up, calls into question the advisability of patch aortoplasty except when it has specific advantages. Other surgical techniques such as subclavian flap angioplasty in infants and young children or radical excision with end-to-end anastomosis may be preferable where there is no anatomical contraindication. In any case, lifelong yearly review of postoperative patients should include chest X-ray and further investigation by computerized tomography scanning or other suitable imaging of those with suspicious findings.

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.

Management of ascending aortic dissection: experience with the USCI intraluminal prosthesis and a method of aortic valve repair.

Ten consecutive cases of acute ascending aortic dissection operated on using the USCI intraluminal prosthesis from 1983 to 1986 were reviewed. Diagnosis was achieved by conventional angiography in six cases, by intraarterial digital subtraction angiography in one case, by computerized tomography (CT) scan in two cases and by echocardiography and abdominal ultrasound in one case. An entry site was seen in only five out of six conventional angiograms. At operation six of the 10 had a degree of tamponade. Aortic regurgitation was seen five times, due to dissection in four cases and to Marfan's disease in one. The entry site was controlled in eight cases. Repair using intraluminal prosthesis only was achieved in five cases. Aortic valve repair was added in four out of 10 cases, and in one of these an aorta-to-right coronary graft was also added. One case required aortic valve replacement. A method of aortic valve repair is presented. There were nine survivors, 1-36 months postoperatively. Of these, eight were asymptomatic on no medication. One had severe aortic regurgitation noted 2 months postoperatively and has mildly reduced exercise tolerance. Surgical treatment can be planned if the presence of dissection is proven and involvement of the ascending aorta is demonstrated. Early surgery is important, since six of the 10 cases in this series had tamponade. The intraluminal graft will reliably redirect flow to the true lumen and exclude the dissection from the pericardium. Aortic valve repair can be successful though late replacement may be necessary in some cases. Control of the entry site is not essential to achieve a good clinical result.

Aorta-coronary bypass grafting with polytetrafluoroethylene conduits. Early and late outcome in eight patients.

During 1982 and 1983 we performed aorta-coronary bypass grafts on eight patients using 4 mm polytetrafluoroethylene conduits and predominantly the multiple sequential graft technique. Angiography was performed 1 week postoperatively and seven of eight patients had patent grafts and were angina free. At 1 year's follow-up 18 of 28 distal anastomoses were patent and five of eight patients were angina free. At 45 month's follow-up four of 28 distal anastomoses were patent and one of eight patients was angina free.

Total intracardiac repair for tetralogy of Fallot in adults.

The anatomic and clinical features of 47 patients who were 18 years of age or older at the time of total intracardiac repair for tetralogy of Fallot are reviewed. Twenty (43%) patients had had previous palliative surgery. Of 14 pulmonary-systemic shunts, 9 (64%) remained patent. The location of the ventricular septal defect was infracristal in 90% of patients. The predominant right ventricular outflow tract obstruction was at the infundibulum in 30%; another 64% of patients had combined valvular and infundibular obstruction. Total intracardiac repair was achieved; hospital mortality was 8.5%. Morbidity was minor, and hemorrhage was a significant problem in only 2 patients. Thirty-five patients have been followed from 11 months to 15 years after surgery. There were 4 late deaths; the actuarial 10-year survival rate was 82%.

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.