Phentolamine as a Treatment for Poor Mixing in Transposition of the Great Arteries with Adequate Intraatrial Communication

Patients with transposition of the great arteries often show poor mixing for different reasons, even after adequate balloon atrial septostomy. We present a patient with such a lesion whose clinical status improved dramatically after phentolamine was applied. We believe this improvement is due to reduction in afterload caused by the α₂ blocker and also possibly as a response to a presumptive effect of the drug on the diastolic function of the right ventricle, allowing more left-to-right shunt across the atrial septal defect. Both phenomena can improve cardiac output in such a situation.     

前列腺素E1治疗新生儿完全性大动脉转位的疗效

目的了解前列腺素E1治疗新生儿完全性大动脉转位时在维持血氧饱和度、延长患儿存活时间方面的作用。方法19例大动脉错位患儿分为两组。治疗组11例采用前列地尔静脉24h持续滴注,5~20ng/(kg·min);对照组8例采用一般治疗。用药期间监测患儿体温、血氧饱和度、心率、血压等指标。结果治疗组血氧饱和度为(82.30±3.56)%,对照组为(67·30±4.54)%,二者比较有显著性差异(t=8.232P=0.001),其存活时间明显长于对照组;治疗组体温、心率、血压等指标未见明显波动。结论前列腺素E1对维持完全性大动脉转位患儿的动脉导管开放、改善血氧饱和度、延长存活时间具有良好作用。     

Evaluation of Right Ventricular Performance Long After the Atrial Switch Operation for Transposition of the Great Arteries Using the Doppler Tei Index

Right ventricular (RV) dysfunction may occur in patients after the atrial switch operation for d-transposition of the great arteries (d-TGA) and can be an important complication. Noninvasive assessment of RV function using echocardiography is necessary for following up these patients. We evaluated RV function using the Doppler Tei index (RV Tei index). The RV Tei index measures the ratio of total time intervals in isovolumetric contraction and relaxation to the ejection time. The subjects consisted of 33 patients who had undergone the atrial switch operation for d-TGA (the atrial switch group) (mean age, 21 ± 4 years), 10 patients with pulmonary artery stenosis after the arterial switch operation for d-TGA (the arterial switch group) (mean age, 17 ± 1 years), and 10 patients with a normally structured heart as a control group (mean age, 26 ± 7 years). The RV Tei index (0.65 ± 0.16) was significantly higher in the atrial switch group than in the arterial switch group (0.29 ± 0.07) and the control group (0.29 ± 0.01) (p < 0.05). The fractional area change of the RV obtained from the four-chamber view in the atrial switch group showed a significant negative correlation with the RV Tei index (r = −0.58, p < 0.01). The RV Tei index increased with increasing severity of the NYHA functional class. In the moderate/severe tricuspid regurgitation group, it was significantly higher than in patients with none/trivial tricuspid regurgitation. We conclude that the RV Tei index is useful for evaluating RV junction long after the atrial switch operation for d-TGA.     

Left Ventricular Function in Patients with Transposition of the Great Arteries Operated with Atrial Switch

In patients operated with atrial switch for transposition of the great arteries (TGA), the left ventricle (LV) supports the pulmonary circulation and is thus pressure unloaded. Evaluation of LV function in this setting is of importance, as LV functional abnormalities have been documented and might contribute to development of symptoms. The ventricular contraction pattern in 14 Senning-operated TGA patients and 14 healthy controls was studied using tissue Doppler and magnetic resonance imaging. In the subpulmonary LV free wall, longitudinal strain was greater than circumferential strain (−23.6 ± 3.6% vs. −19.1 ± 3.2%, p = 0.002) as in the normal right ventricle (RV) (−30.7 ± 3.3% vs. −15.8 ± 1.3%, p < 0.001), but opposite to findings in the normal LV (−16.5 ± 1.7% vs. −25.7 ± 3.1%, p < 0.001). Subpulmonary strain and strain rate values were intermediate between those in the normal LV and RV. Ventricular free-wall torsion was reduced in the subpulmonary LV compared with both the normal LV (5.7 ± 3.2° vs. 16.7 ± 5.6°, p < 0.001) and RV (5.7 ± 3.2° vs. 11.4 ± 2.6°, p < 0.05). Furthermore, early diastolic filling of the subpulmonary LV differed from that of the normal LV. The subpulmonary LV displayed predominantly longitudinal shortening, as did its functional counterpart, the normal RV. However, the degree and rate of both longitudinal and circumferential shortening were intermediate between those of the normal LV and RV. This could represent a partial adaptation to the reduced pressure load. Decreased ventricular torsion and diastolic abnormalities might indicate subclinical ventricular dysfunction.     

Continuous Nasogastric Infusion of Prostaglandin E2 in Ductus-Dependent Congenital Heart Disease

Prostaglandin E2 (PGE2) was infused continuously through a nasogastric gavage tube in four infants with pulmonary atresia. The drug was given at a rate of 12.5–160 µg/kg/h. The duration of therapy was 7–123 days. The effects and side effects seen by this method were similar to those seen in the conventional multiple dose regimen. This method was an effective and simple way of maintaining the ductus arteriosus open, especially for a long period of time.     

Transposition of the great arteries with posterior aorta: Detection by two-dimensional echocardiography

Summary Two-dimensional echocardiographic features in a case of transposition of the great arteries (TGA) with the posterior aorta are described. The unusual arrangement of the great arteries and the presence of bilateral conuses and aortic-mitral fibrous continuity were clearly demonstrated by angiocardiography and then confirmed at surgery.     

Preseptostomy Myocardial Infarction in a Patient with Complex Transposition of the Great Arteries

In transposition of the great arteries, systemic venous return is preferentially routed to the aorta, and any spontaneous or iatrogenic emboli may therefore cause organ infarction. We present a patient with transposition of the great arteries who developed myocardial infarction prior to balloon septostomy and, also, was later documented to have sustained brain infarction despite adequate precautionary measures. Minimal handling of venous sites in these patients is crucial.     

Recovery Kinetics of Oxygen Uptake Is Abnormally Prolonged in Patients with Mustard/Senning Repair for Transposition of the Great Arteries

The aim of this study was to evaluate the ability to recover from exercise in patients with a Mustard/Senning (M/S) repair for transposition of the great arteries and to identify the major determinants. A total of 40 consecutive patients with a M/S repair at a mean age of 10.0 ± 9.8 months underwent maximal cardiopulmonary exercise testing at 19.5 ± 11.3 years of age. Results were compared to those of a cohort of 153 healthy individuals. Decay of oxygen uptake (VO₂), CO₂ (VCO₂), minute ventilation (VE), heart rate (HR) was calculated for the first minute of recovery. M/S patients had reduced peak VO₂ (22.9 ± 7.2 vs 34.2 ± 9.5 ml O₂/kg/min, p < 0.0001) and VO₂ slope (0.27 ± 0.10 vs 0.47 ± 0.2 L O₂/min, p < 0.0001), Peak O₂ pulse (p < 0.0001) and peak HR (p = 0.001) were reduced. VCO₂ and VE slopes were reduced (p < 0.0001 for both), whereas HR slope was similar (p = 0.38). In M/S patients, the only independent determinants of VO₂ slope during recovery were pulse O₂ slope (p < 0.0001) and VCO₂ slope (p < 0.0001). In M/S patients, a limited cardiopulmonary reserve affects not only maximal exercise responses but also the recovery phase. A prolonged recovery of O₂ pulse and a prolonged CO₂ retention with subsequent prolonged hyperpnea are the main determinants of the delayed recovery.     

Metabolic Alterations and Neurodevelopmental Outcome of Infants with Transposition of the Great Arteries

Abnormal neurodevelopment has been reported for infants who were born with transposition of the great arteries (TGA) and underwent arterial switch operation (ASO). This study evaluates the cerebral metabolism of TGA infants at birth and before ASO and neurodevelopment 1 year after ASO. Proton magnetic resonance spectroscopy (¹H-MRS) was performed on 16 full-term TGA brains before ASO within 3–6 days after birth. The brain metabolite ratios of [NAA/Cr], [Cho/Cr], and [mI/Cr] evaluated measured. Ten infants were evaluated at 1 year using the Bayley Scales of Infants Development II (BSED II). Cerebral metabolism of infants with TGA was altered in parietal white matter (PWM) and occipital gray matter (OGM) at birth before ASO. One year after ASO, [Cho/Cr] in PWM remained altered, but all metabolic ratios in OGM were normal. The results of BSID II at 1 year showed delayed mental and psychomotor development. This delayed neurodevelopmental outcome may reflect consequences of the altered cerebral metabolism in PWM measured by ¹H-MRS. It is speculated that the abnormal hemodynamics due to TGA in utero may be responsible for the impaired cerebral metabolism and the subsequent neurodevelopmental deficit.     

Aortic atresia and tricuspid atresia occurring in complete transposition of the great vessels

Summary A unique case of aortic atresia and tricuspid atresia associated with transposition of the great vessels is described in a newborn infant. The clinical, echocardiographic, and heart catheterization data are presented. The embryological and surgical implications are discussed.     

Primary Surgical Correction of Transposition of the Great Arteries and Atrioventricular Septal Defect Associated with Left Isomerism

We report successful primary surgical repair of transposition of the great arteries (TGA) and complete atrioventricular septal defect (AVSD) associated with left isomerism {I,L,L} without pulmonary obstruction in a 1-month-old infant. The operative procedure consisted of an arterial switch and a two-patch repair of the AVSD. To the best of our knowledge, this is the first report of successful primary surgical repair of TGA and AVSD with left isomerism. Primary anatomic correction of this defect combination is feasible in patients with left isomerism.     

先天性纠正型大动脉错位不同手术方法结果的比较

目的 比较先天性纠正型大动脉错位(ccTGA)的各种手术治疗结果方法,为临床治疗ccTGA提出更合理的手术方式.方法 1999年6月至2009年12月外科手术治疗95例ccTGA,包括传统纠治手术25例,功能性单心室纠治手术26例,双调转术(Double Switch)手术26例,姑息手术15例,另有3例接受其他手术.结果 术后死亡7例,其中传统手术组死亡2例,Double Switch手术组死亡4例,其他手术组死亡1例,单心室手术组全部存活.结论 纠正型大动脉错位的手术方法的选择取决于解剖条件和生理参数.在各类手术结果的比较中,功能性单心室纠治手术的死亡率低、并发症少、再手术率低,可适当放宽功能性单心室纠治手术指征,可能得到更好的治疗效果.但长期的手术疗效还有待于进一步随访.

Abstract：

Objective To study the clinical outcomes of various corrective surgeries for congenitally corrected transposition of the great arteries (ccTGA) in children. Methods Between June 1999 and December 2009, 95 patients with ccTGA who underwent corrective surgeries at this center were enrolled in this study. Among the 95 patients, 25 patients were performed conventional surgical repairs, 26 had functionally univentricular surgical repair, 26 had double switch operation, 15 had palliative surgeries, and 3 underwent other surgical treatments. Results Seven deaths after surgery were recorded, including 2 patients who had conventional surgical repairs, 4 with double switch operation and 1 with other surgical treatments. No death of the patients who underwent functionally univentricular surgical repair was noted. Conclusions The surgical strategy to correct ccTGA should be made according to patient's individual anatomic anomalies and pathophysiology. Short term outcome study revealed that functionally univentricular surgical repair is safe and effective.     

Symptomatic Aorto-Pulmonary Collaterals Early After Arterial Switch Operation

Enlarged bronchial arteries and/or systemic-to-pulmonary collaterals have been frequently demonstrated in association with transposition of the great arteries. They are usually clinically silent, although they might be large enough to cause accelerated pulmonary vascular obstructive disease or symptomatic cardiac volume overload after surgical repair. We report on a low-weight neonate with transposition of the great arteries and intact ventricular septum who showed a stormy postoperative course because of multiple aorto-pulmonary collaterals early after a successful arterial switch operation. Percutaneous coil embolization of these anomalous vessels resulted in sudden weaning from mechanical ventilation and hospital discharge in a few weeks.     

Unusual Longevity Without Surgical Intervention in Complete Transposition of the Great Arteries

A case of unusual longevity to the age of 58 years is reported for a female patient with complete transposition of the great arteries. The association with a wide atrial septal defect with intact interventricular septum may have contributed to the long survival without surgery. Factors determining intercirculatory mixing and systemic oxygen saturation may be the high pulmonary flow, the location of the anatomic communication, sufficient hemoglobin concentration to allow an adequate level of systemic resistance and recirculated systemic flow, and the belated development of pulmonary vascular disease.     

Prostaglandin E2 administration in infants with ductus-dependent cyanotic congenital heart disease

Prostaglandin E₂ was administered to 22 newborns with ductus-dependent cyanotic congenital heart disease. Twelve patients had pulmonary atresia and ten simple dextrotransposition of the great arteries. Patients were classified into two groups: group 1 (n=11) received prostaglandin E₂ by the intravenous route (dose: 0.01–0.05 g/kg per min); group 2 (n=11) received prostaglandin E₂ by the oral route (dose: 35–65 g/kg per 1–4 h). Treatment lasted for 1–90 days. All infants except one of group 2 showed a significant (>10 Torr) increase in PaO₂ following PGE₂ administration. The mean increase in PaO₂ was higher (P<0.01) in group 1 (21.8±1.7, Torr) than in group 2 (15.8±1.5, Torr). PaO₂ fell significantly (P<0.01) in five patients of group 1 who continued treatment orally with satisfactory (>30 Torr) levels in four of them. Severe side effects were observed only in group 1. The data show that similarly to prostaglandin E₁ infusions, prostaglandin E₂, given i.v. or orally, is useful in the management of infants with ductus-dependent cyanotic congenital heart disease. Oral prostaglandin E₂, administration is less effective than i.v. infusions, but can be used for long-term, therapy being more convenient and causing minimal morbidity.Presented at the IX European Congress of Perinatal Medicine, Dublin, Ireland, 1984     

Prevalence of Arrhythmias and Their Risk Factors Mid- and Long-Term After the Arterial Switch Operation

Early results of the arterial switch operation (ASO) for transposition of the great arteries (TGA) are good, but there are few mid- and long-term data on postoperative arrhythmias, especially in Japan. In this study, clinical data on 624 1-year survivors who had an ASO between 1976 and 1995 were collected from six institutes in Japan up to October 2002. Sixty (9.6%) 1-year survivors had significant arrhythmias. Bradycardia occurred in 22 patients, including complete atrioventricular block (CAVB) in 12, sick sinus syndrome (SSS) in 6, and second-degree atrioventricular block in 4. Syncope developed in 2 with CAVB and 2 with SSS. Ten patients with bradycardia underwent permanent pacemaker implantation. Supraveutricular tachycardia (SVT) was seen in 25 patients, including paroxysmal supraventricular tachycardia in 16, atrial flutter in 7, and atrial fibrillation in 2. Six patients with SVT received antiarrhythmic medication. SVT was transient in 20 and persistent in 5. Ventricular arrhythmias occurred in 13 patients, including nonsustained ventricular tachycardia in 5, paroxysmal ventricular contractions with couplets in 5, ventricular flutter in 2, and sustained ventricular tachycardia in 1. Four patients with ventricular arrhythmias received antiarrhythmic medication. Of the study patients, 8 died 1 year or more after ASO. Death was directly related to arrhythmia in 1 patient and was due to nonsustained ventricular tachycardia with severe congestive heart failure. The presence of a ventricular septal defect (VSD) was a risk factor for postoperative arrhythmia. Patients with TGA and VSD had more arrhythmias than those with TGA and an intact ventricular septum (13.7 vs 8.7%, p < 0.05), and this was especially true for CAVB (3.9% vs 1.0%, p < 0.05). In 36 patients clearly documented time onset of postoperative arrhythmia arrhythmia developed in 18 (50%) after less than 1 year and in 15 (42%) after more than 5 years. In summary serious arrhythmias after ASO were uncommon, but postoperative arrhythmias, such as unpaced CAVB, SSS, and VT, were related to morbidity and mortality. VSD was a risk factor for postoperative arrhythmia, especially CAVB. Approximately half of the arrhythmias developed late. Lifelong monitoring with respect to arrhythmia is needed for patients after ASO.     

Follow-up outcomes 10 years after arterial switch operation for transposition of the great arteries: comparison of cardiological health status and health-related quality of life to those of the a normal reference population

The purpose of this study was to investigate the cardiological health status and health-related quality of life after the arterial switch operation (ASO) for transposition of the great arteries (TGA) in comparison with a normative reference group. Chart review and cross-sectional systematic follow-up, including echocardiography, exercise testing, and electrocardiography, were performed on all survivors of ASO for TGA between 1990 and 1995. Health-related quality of life (HRQOL) was assessed using a standardized questionnaire. A normative reference group was included. Forty-nine survivors [median age at operation 13 days, mean age at follow-up 11 +/- 2 years (37/49 with intact ventricular septum] were identified. Thirty-three of 49 patients (67%) [22/33 TGA with intact ventricular septum (IVS)] participated in cross-sectional follow-up. Cumulative 10-year event-free survival was 88% and the re-intervention rate 6%. Aortic root dilatation occurred in 70% of patients; none had severe aortic regurgitation. Left ventricular function was normal. Exercise performance (85% of reference capacity, p = 0.02), maximal oxygen uptake (85%, p < 0.01) and peak heart rate (95%, p < 0.01) were decreased. Exercise electrocardiogram was normal as was rhythm status. Unfavourable outcomes on HRQOL were found for motor functioning and positive emotional functioning. Overall there were no significant differences between TGA/IVS and TGA/VSD. We conclude that at mid- to long-term follow-up after ASO, major events and re-interventions (6%) occur infrequently. Exercise capacity and maximal oxygen uptake are lower than those in a reference population, which could not be related to diminished ventricular function. Aortic root dilatation is frequent, irrespective of the anatomical subgroup. Severe aortic regurgitation or left ventricular dilatation was not found. The unfavourable health-related quality of life deserves further attention.     

Premature ``Closing' of the Foramen Ovale in Transposition of the Great Arteries with Intact Ventricular Septum: Rare Cause of Sudden Neonatal Death

We report a male neonate who developed severe cyanosis and bradycardia at birth unresponsive to resuscitation. At autopsy he was found to have premature ``closure' of the foramen ovale together with transposition of the great arteries and an intact ventricular septum. Reviewing the literature, we found only one case report describing a similar neonate with this lethal combination of cardiac malformations.     

Inducible polymorphous ventricular tachycardia following Mustard operation for transposition of the great arteries

Summary A 22-year-old woman with chronic atrial tachycardia following Mustard's operation for transposition of the great arteries presented with dizziness and ventricular tachycardia documented with dynamic 24-h electrocardiogram. During intracardiac electrophysiology study, programmed ventricular extrastimulation induced polymorphous ventricular tachycardia (torsades de pointes). This was prevented by intravenous administration of procainamide. We postulate that polymorphous ventricular tachycardia is a possible cause of death in patients with Mustard's operation. Postoperative electrophysiologic study may define those patients at risk to develop this potentially fatal arrhythmia.This work was supported in part by Institutional Training grant HL 07387 and research grants HL 18794 and HL 23566 from the National Institutes of Health, Bethesda, Maryland, and a grant from the Bane Estate, Chicago, Illinois.