Congenital heart disease does not entail an increased risk for severe COVID-19.

AIM: To analyse the risk of developing serious disease or death due to COVID-19 among patients who underwent heart surgery during childhood. METHODS: A retrospective combined register and patient file study. We identified all individuals who had undergone surgery for congenital heart disease in childhood between 1994 and 2019 in our Local Surgical Register that covers half of the Swedish population. This effort was cross-tabulated with the diagnosis of COVID-19 entered in the National Register of Diagnoses in Sweden from 1 March 2020 to 1 March 2021. Severe disease was defined as treatment at an intensive care unit (ICU). RESULTS: We identified 3950 individuals, and the median age at follow-up was 16 years (1-44). A total of 32 patients were diagnosed with COVID-19. Five of them were hospitalised for more than 2 days (5-32 days). Two adults required treatment at an ICU; both had additional comorbidity and one died. The corresponding number of ICU stays for this age range in Sweden was 2020 approximately 0.13/1000 person-years, reported from The Swedish Intensive Care Registry. CONCLUSIONS: There was no increased rate of severe COVID-19 among individuals who had undergone surgery for congenital heart disease in childhood. Additional comorbidity is related to outcome.

Impact of Left Ventricular Morphology on Adverse Outcomes Following Stage 1 Palliation for Hypoplastic Left Heart Syndrome: 20 Years of National Data From Sweden.

Background Hypoplastic left heart syndrome is associated with significant morbidity and mortality. We aimed to assess the influence of left ventricular morphology and choice of shunt on adverse outcome in patients with hypoplastic left heart syndrome and stage 1 palliation. Methods and Results This was a retrospective analysis of patients with hypoplastic left heart syndrome with stage 1 palliation between 1999 and 2018 in Sweden. Patients (n=167) were grouped based on the anatomic subtypes aortic-mitral atresia, aortic atresia-mitral stenosis (AA-MS), and aortic-mitral stenosis. The left ventricular phenotypes including globular left ventricle (Glob-LV), miniaturized and slit-like left ventricle (LV), and the incidence of major adverse events (MAEs) including mortality were assessed. The overall mortality and MAEs were 31% and 41%, respectively. AA-MS (35%) was associated with both mortality (all other subtypes versus AA-MS: interstage-I: hazard ratio [HR], 2.7; P=0.006; overall: HR, 2.2; P=0.005) and MAEs (HR, 2.4; P=0.0009). Glob-LV (57%), noticed in all patients with AA-MS, 61% of patients with aortic stenosis-mitral stenosis, and 19% of patients with aortic atresia-mitral atresia, was associated with both mortality (all other left ventricular phenotypes versus Glob-LV: interstage-I: HR, 4.5; P=0.004; overall: HR, 3.4; P=0.0007) and MAEs (HR, 2.7; P=0.0007). There was no difference in mortality and MAEs between patients with AA-MS and without AA-MS with Glob-LV (P>0.15). Patients with AA-MS (35%) or Glob-LV (38%) palliated with a Blalock-Taussig shunt had higher overall mortality compared with those palliated with Sano shunts, irrespective of the stage 1 palliation year (AA-MS: HR, 2.6; P=0.04; Glob- LV: HR, 2.1; P=0.03). Conclusions Glob-LV and AA-MS are independent morphological risk factors for adverse short- and long- term outcome, especially if a Blalock-Taussig shunt is used as part of stage 1 palliation. These findings are important for the clinical management of patients with hypoplastic left heart syndrome.

Outcome after surgery for pulmonary atresia with ventricular septal defect, a long-term follow-up study.

AIM: To study the long-term outcome after surgery for pulmonary atresia and ventricular septal defect (PA-VSD), and to determine association between the contribution of major aorto-pulmonary collateral arteries (MAPCAs) to the pulmonary blood flow, comorbidity and cause of death. METHODS: Patients who had undergone surgery for PA-VSD from January 1st 1994 to December 31st 2017 were studied retrospectively. Survival was cross-checked against the Swedish National Population Register. RESULTS: Seventy patients were identified, giving an incidence of 5.3 newborns per 100 000 live births. In 41 patients (59%) the pulmonary blood flow originated from a patent ductus arteriosus (PDA), while 29 patients (41%) had contribution of the pulmonary blood flow from MAPCAs. Extracardiac disease was found in 34 patients (49%), 16 of whom had 22q11-microdeletion syndrome (23%). Survival at follow-up was similar in patients with and without MAPCAs (72.4% vs. 75.6%, n.s.), with a median follow-up time of 14.3 years (3.2-41.8 years). No difference was found in mortality in patients with or without any syndrome or extracardiac disease. CONCLUSION: Long-term survival did not differ between those with and without MAPCAs and no difference in mortality was seen in patients with and without concomitant extracardiac disease or any kind of syndrome.

A national study of the outcome after treatment of critical aortic stenosis in the neonate.

OBJECTIVE: This study describes short-term and long-term outcome after treatment of critical valvular aortic stenosis in neonates in a national cohort, with surgical valvotomy as first choice intervention. METHODS: All neonates in Sweden treated for critical aortic stenosis between 1994 and 2016 were included. Patient files were analysed and cross-checked against the Swedish National Population Registry as of December 2017, giving complete survival data. Diagnosis was confirmed by reviewing echo studies. Critical aortic stenosis was defined as valvular stenosis with duct-dependent systemic circulation or depressed left ventricular function. Primary outcome was all-cause mortality and secondary outcomes were reintervention and aortic valve replacement. RESULTS: Sixty-one patients were identified (50 boys, 11 girls). Primary treatment was surgical valvotomy in 52 neonates and balloon valvotomy in 6. Median age at initial treatment was 5 days (0-26), and median follow-up time was 10.8 years (0.14-22.6). There was no 30-day mortality but four late deaths. Freedom from reintervention was 66%, 61%, 54%, 49%, and 46% at 1, 5, 10, 15, and 20 years, respectively. Median time to reintervention was 3.4 months (4 days to 17.3 years). Valve replacement was performed in 23 patients (38%). CONCLUSIONS: Surgical valvotomy is a safe and reliable treatment in these critically ill neonates, with no 30-day mortality and long-term survival of 93% in this national study. At 10 years of age, reintervention was performed in 54% and at end of follow-up 38% had had an aortic valve replacement.

Pacemaker treatment after Fontan surgery-A Swedish national study.

OBJECTIVE: Fontan surgery is performed in children with univentricular heart defects. Previous data regarding permanent pacemaker implantation frequency and indications in Fontan patients are limited and conflicting. We examined the prevalence of and risk factors for pacemaker treatment in a consecutive national cohort of patients after Fontan surgery in Sweden. METHODS: We retrospectively reviewed all Swedish patients who underwent Fontan surgery from 1982 to 2017 (n = 599). RESULTS: After a mean follow-up of 12.2 years, 13% (78/599) of the patients with Fontan circulation had received pacemakers. Patients operated with the extracardiac conduit (EC) type of total cavopulmonary connection had a significantly lower prevalence of pacemaker implantation (6%) than patients with lateral tunnel (LT; 17%). Mortality did not differ between patients with (8%) and without pacemaker (5%). The most common pacemaker indication was sinus node dysfunction (SND) (64%). Pacemaker implantation due to SND was less common among patients with EC. Pacemaker implantation was significantly more common in patients with mitral atresia (MA; 44%), double outlet right ventricle (DORV; 24%) and double inlet left ventricle (DILV; 20%). In contrast, patients with pulmonary atresia with intact ventricular septum and hypoplastic left heart syndrome were significantly less likely to receive a pacemaker (3% and 6%, respectively). CONCLUSIONS: Thirteen percent of Fontan patients received a permanent pacemaker, most frequently due to SND. EC was associated with a significantly lower prevalence of pacemaker than LT. Permanent pacemaker was more common in patients with MA, DORV, and DILV.

Treatment of valvular aortic stenosis in children: a 20-year experience in a single institution.

OBJECTIVES: This study presents short- and long-term follow-up after treatment for isolated valvular aortic stenosis in children with surgical valvotomy as the preferred 1st intervention. METHODS: All patients aged 0-18 years treated between 1994 and 2013 at our centre were reviewed regarding the mode of first treatment, mortality, reinterventions and the need for aortic valve replacement. RESULTS: A total of 113 patients were identified in local registries. There were 44 neonates, 31 infants and 38 children. The mean follow-up period was 11 years (range 2-22 years). No early deaths and only 2 late deaths were reported. Of the 113 patients, 92 patients had open surgical valvotomy as the 1st intervention. Freedom from reintervention was 80%, 69%, 61%, 57% and 56% at 1, 5, 10, 15 and 20 years, respectively. The main indication for reintervention was valvular stenosis. Freedom from aortic valve replacement was 67%. CONCLUSIONS: Surgical valvotomy of aortic stenosis in this long-term follow-up study resulted in no 30-day mortality and <1% late mortality. Reinterventions were common, with 38% of the patients having further surgery or catheter treatment of the aortic valve before the age of 18 years. Among the 40 patients aged 18 years or older at follow-up, 45% had had the aortic valve replaced. Our data do not allow comparison of catheter and surgical treatment, but, based on these results, we find no reason to change our current policy of surgical treatment as 1st intervention in patients with isolated valvular aortic stenosis.

Do Self- and Proxy Reports of Cognitive Problems Reflect Intellectual Functioning in Children and Adolescents with Congenital Heart Defects?

AIM: Children with congenital heart defects (CHD) who suffer from cognitive impairments and school difficulties need to be identified as early as possible in order to set appropriate interventions in place that may enhance the school situation and quality of life for these children. Identifying children and adolescents at risk for cognitive difficulties requires specific screening tools. This study assessed such a tool - Pediatric Quality of Life Inventory Cardiac Module subscale: Cognitive Problems - to investigate whether proxy reported and self-reported cognitive problems were associated with measured intellectual functioning in children and adolescents with CHD treated with surgery or by catheter interventions. METHOD: The sample consisted of 184 children/adolescents aged 3, 5, 9, and 15 years. The severity of the CHD diagnoses was categorized into three groups (mild, moderate, or severe) for all age groups. For all the age groups, we collected proxy ratings of cognitive problems, and for the 5-, 9-, and 15-year-olds, we also collected self-reported cognitive problems. Intellectual functioning was measured with the Wechsler intelligence scales. The control variables were socioeconomic status and severity of diagnosis. RESULTS: A strong association was found between the parent's ratings of cognitive problems and the children's and adolescents' results on the Wechsler scales. This association was present for all ages, including the 3-year-olds. As for the self-reports, an association was only found between the 15-year-olds self-report of cognitive problems and their results on the Wechsler scales. CONCLUSION: To identify children with cognitive problems as early as at the age of 3 years, parent-rated Pediatrics Quality of Life subscale: Cognitive Problems can be used as a screening tool. For 15-year-olds, the self-report ratings can be used as a screening tool. We also suggest a cutoff score of 80 for both the 15-year olds as well as the proxy reports. If the score falls below 80 the child should be formally evaluated using standardized cognitive test.

Intellectual Functioning in Children with Congenital Heart Defects Treated with Surgery or by Catheter Interventions.

BACKGROUND: Studies suggest that children with congenital heart defects (CHD) are at risk for adverse intellectual functioning. However, factors related to lower intellectual functioning in this group are largely unknown. This study describes intellectual functioning in children with CHD in relation to severity of the heart defect, the child's age, and the socioeconomic status of the family (SES). METHODS: Two hundred twenty-eight children treated with surgery or by catheter technique were tested using the Wechsler intelligence scales to determine full scale IQ (FSIQ). FSIQ was then analyzed in relation to age (3-, 5-, 9-, and 15-year olds), severity of the diagnosis (mild, moderate, and severe), and SES (low, medium, and high). The median age was 70 months (5.8 years) with a range of 162 months [30 months (2.5 years) to 192 months (16.0 years)]. RESULTS: The total mean score on FSIQ was 100.8 (SD = 14.5). Children with severe CHD had significantly lower FSIQ than children with mild and moderate CHD, and 9- and 15-year olds had significantly lower FSIQ compared to the 3-year olds. Children from families with low SES had significantly lower FSIQ than children from medium SES and high SES families. No interaction between severity of diagnosis, age, and SES was found for FSIQ. CONCLUSION: Eighty-three percent of the children with CHD performed at or above average with respect to FSIQ. SES and severity of diagnosis had significant main effects on FSIQ. These factors should be considered when planning interventions and follow-up programs for children with CHD.

Altered expression of autoimmune regulator in infant down syndrome thymus, a possible contributor to an autoimmune phenotype.

Down syndrome (DS), caused by trisomy of chromosome 21, is associated with immunological dysfunctions such as increased frequency of infections and autoimmune diseases. Patients with DS share clinical features, such as autoimmune manifestations and specific autoantibodies, with patients affected by autoimmune polyendocrine syndrome type 1. Autoimmune polyendocrine syndrome type 1 is caused by mutations in the autoimmune regulator (AIRE) gene, located on chromosome 21, which regulates the expression of tissue-restricted Ags (TRAs) in thymic epithelial cells. We investigated the expression of AIRE and TRAs in DS and control thymic tissue using quantitative PCR. AIRE mRNA levels were elevated in thymic tissue from DS patients, and trends toward increased expression of the AIRE-controlled genes INSULIN and CHRNA1 were found. Immunohistochemical stainings showed altered cell composition and architecture of the thymic medulla in DS individuals with increased frequencies of AIRE-positive medullary epithelial cells and CD11c-positive dendritic cells as well as enlarged Hassall's corpuscles. In addition, we evaluated the proteomic profile of thymic exosomes in DS individuals and controls. DS exosomes carried a broader protein pool and also a larger pool of unique TRAs compared with control exosomes. In conclusion, the increased AIRE gene dose in DS could contribute to an autoimmune phenotype through multiple AIRE-mediated effects on homeostasis and function of thymic epithelial cells that affect thymic selection processes.

Total anomalous pulmonary venous connection: outcome of postoperative pulmonary venous obstruction.

OBJECTIVE: Pulmonary venous obstruction (PVO) is an important cause of late mortality in total anomalous pulmonary venous connection (TAPVC). We aimed to describe current practices for the management of postoperative PVO and the efficacy of the different interventional procedures. METHODS: We conducted a retrospective international collaborative population-based study involving 19 pediatric cardiac centers in the United Kingdom, Ireland, and Sweden. Patients with TAPVC born between January 1, 1998, and December 31, 2004, were identified. Patients with functionally univentricular circulation or atrial isomerism were excluded. All available data and images were reviewed. RESULTS: Of 406 patients undergoing repair of TAPVC, 71 (17.5%) had postoperative PVO. The diagnosis was made within 6 months of surgery in 59 (83%) of the 71 patients. In 12, serial imaging documented change in appearance of the pulmonary veins. Good-sized pulmonary veins can progress to diffusely small veins and rarely atresia. Patients presenting after 6 months had less severe disease; all are alive at most recent follow-up. Fifty-six (13.8%) of 406 patients underwent intervention for postoperative PVO: 44 had surgical treatment and 12 had an initial catheter intervention. One half underwent 1 or more reinterventions. Three-year survival for patients with postoperative PVO was 58.7% (95% confidence intervals, 46.2%-69.2%) with a trend that those having a surgical strategy did better (P = .083). Risk factors for death included earlier presentation after TAPVC repair, diffusely small pulmonary veins at presentation of postoperative PVO, and an increased number of lung segments affected by obstruction. CONCLUSIONS: Postoperative PVO tends to appear in the first 6 months after TAPVC repair and can be progressive. Early intervention for PVO may be indicated before irreversible secondary changes occur.

Total anomalous pulmonary venous connection: morphology and outcome from an international population-based study.

BACKGROUND: late mortality after repair of total anomalous pulmonary venous connection is frequently associated with pulmonary venous obstruction (PVO). We aimed to describe the morphological spectrum of total anomalous pulmonary venous connection and identify risk factors for death and postoperative PVO. METHODS AND RESULTS: we conducted a retrospective, international, collaborative, population-based study involving all 19 pediatric cardiac centers in the United Kingdom, Ireland, and Sweden. All infants with total anomalous pulmonary venous connection born between 1998 and 2004 were identified. Cases with functionally univentricular circulations or atrial isomerism were excluded. All available data and imaging were reviewed. Of 422 live-born cases, 205 (48.6%) had supracardiac, 110 (26.1%) had infracardiac, 67 (15.9%) had cardiac, and 37 (8.8%) had mixed connections. There were 2 cases (0.5%) of common pulmonary vein atresia. Some patients had extremely hypoplastic veins or, rarely, discrete stenosis of the individual veins. Sixty (14.2%) had associated cardiac anomalies. Sixteen died before intervention. Three-year survival for surgically treated patients was 85.2% (95% confidence interval 81.3% to 88.4%). Risk factors for death in multivariable analysis comprised earlier age at surgery, hypoplastic/stenotic pulmonary veins, associated complex cardiac lesions, postoperative pulmonary hypertension, and postoperative PVO. Sixty (14.8%) of the 406 patients undergoing total anomalous pulmonary venous connection repair had postoperative PVO that required reintervention. Three-year survival after initial surgery for patients with postoperative PVO was 58.7% (95% confidence interval 46.2% to 69.2%). Risk factors for postoperative PVO comprised preoperative hypoplastic/stenotic pulmonary veins and absence of a common confluence. CONCLUSIONS: preoperative clinical and morphological features are important risk factors for postoperative PVO and survival.

Exercise performance after surgery for pulmonary atresia and intact ventricular septum.

The objective of this study was to assess exercise performance in subjects born in Sweden between 1980 and 1995 and undergoing surgery for pulmonary atresia and intact ventricular septum and to identify determinants of exercise performance. Twenty-seven subjects, 16 with biventricular repair and 11 with univentricular palliation, and 28 age- and sex-matched controls completed cardiopulmonary exercise and lung function testing. Peak oxygen uptake was determined using a symptom-limited ramp bicycle exercise protocol. Regression analysis was performed to identify predictors of peak oxygen uptake (V'O(2)), The index group had lower peak V'O(2) (1.4 [median 0.8; range 2.5] l/min) than controls (1.9 [0.7; 3.1]; p < 0.05). Subjects without ventriculocoronary arterial communications (VCAC), corrected to biventricular circulation, had higher peak V'O(2), than the remaining index subjects. Decreased total lung capacity, low minute ventilation, and high physiologic dead space measured at peak exercise were all independent determinants of low peak V'O(2) Exercise capacity is generally decreased in subjects with pulmonary atresia and intact ventricular septum, although there are marked interindividual differences. Good exercise capacity was found in subjects without VCAC who had undergone biventricular repair. Decreased lung function was an unfavourable predictor of exercise capacity.

Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening study in 39,821 newborns.

OBJECTIVE: To evaluate the use of pulse oximetry to screen for early detection of life threatening congenital heart disease. DESIGN: Prospective screening study with a new generation pulse oximeter before discharge from well baby nurseries in West Götaland. Cohort study comparing the detection rate of duct dependent circulation in West Götaland with that in other regions not using pulse oximetry screening. Deaths at home with undetected duct dependent circulation were included. SETTING: All 5 maternity units in West Götaland and the supraregional referral centre for neonatal cardiac surgery. PARTICIPANTS: 39,821 screened babies born between 1 July 2004 and 31 March 2007. Total duct dependent circulation cohorts: West Götaland n=60, other referring regions n=100. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive and negative predictive values, and likelihood ratio for pulse oximetry screening and for neonatal physical examination alone. RESULTS: In West Götaland 29 babies in well baby nurseries had duct dependent circulation undetected before neonatal discharge examination. In 13 cases, pulse oximetry showed oxygen saturations

Abnormalities in myocardial perfusion after surgical correction of pulmonary atresia with intact ventricular septum.

We describe the results of myocardial perfusion scintigraphy performed 4 to 15 years after surgery in 12 patients with pulmonary atresia and intact ventricular septum. We used single photon emission computed tomography after injection of technetium Tc-99m tetrofosmin at submaximal exercise test. The patients, 7 girls and 5 boys, with a mean age of 11 years, and a range from 6 to 19 years, had either undergone biventricular repair, in 5 cases, or univentricular palliation in the remaining 7. This second group included 4 patients with ventriculo-coronary arterial communications. Of the children, 3 with biventricular repair and 6 with univentricular palliation had perfusion defects. Children with biventricular repair had perfusion defects in the ventricular septum, while those having univentricular palliation also had defects located to the left ventricular free wall. All children with ventriculo-coronary arterial communications had perfusion defects both in the ventricular septum and in the left ventricular free wall.

Alpha-cardiac actin mutations produce atrial septal defects.

Atrial septal defect (ASD) is one of the most frequent congenital heart defects (CHDs) with a variable phenotypic effect depending on the size of the septal shunt. We identified two pedigrees comprising 20 members segregating isolated autosomal dominant secundum ASD. By genetic mapping, we identified the gene-encoding alpha-cardiac actin (ACTC1), which is essential for cardiac contraction, as the likely candidate. A mutation screen of the coding regions of ACTC1 revealed a founder mutation predicting an M123V substitution in affected individuals of both pedigrees. Functional analysis of ACTC1 with an M123V substitution shows a reduced affinity for myosin, but with retained actomyosin motor properties. We also screened 408 sporadic patients with CHDs and identified a case with ASD and a 17-bp deletion in ACTC1 predicting a non-functional protein. Morpholino (MO) knockdown of ACTC1 in chick embryos produces delayed looping and reduced atrial septa, supporting a developmental role for this protein. The combined results indicate, for the first time, that ACTC1 mutations or reduced ACTC1 levels may lead to ASD without signs of cardiomyopathy.

Myocardial metabolism is better preserved after blood cardioplegia in infants.

BACKGROUND: We have previously reported improved hemodynamic function after blood cardioplegia in comparison with crystalloid cardioplegia. Furthermore, lactate was released from the heart after crystalloid cardioplegia but not after blood cardioplegia. The purpose of this study was to determine whether the difference in substrate metabolism between the two cardioplegia methods was restricted to lactate, or whether the difference in metabolic derangement was more extensive. METHODS: Thirty consecutive infants with complete atrioventricular septal defects were included in this prospective, randomized, controlled study. Arterial and coronary sinus blood concentrations of substrates and amino acids were measured after weaning from bypass. RESULTS: After crystalloid cardioplegia, there was a myocardial uptake of glutamate (p = 0.003), leucine (p = 0.03), lysine (p = 0.003), and beta-hydroxybutyrate (p = 0.004), whereas lactate was released (p = 0.03). After blood cardioplegia, there was a myocardial uptake of free fatty acids (p = 0.01) but no uptake of amino acids and no release of lactate. CONCLUSIONS: There are differences in myocardial substrate metabolism between blood cardioplegia and crystalloid cardioplegia, which involve carbohydrates and amino acids. The differences may include lipids but our data in this respect are not conclusive.

Screening for duct-dependant congenital heart disease with pulse oximetry: a critical evaluation of strategies to maximize sensitivity.

AIM: To evaluate the feasibility of detecting duct-dependent congenital heart disease before hospital discharge by using pulse oximetry. DESIGN: Case-control study. SETTING: A supra-regional referral centre for paediatric cardiac surgery in Sweden. PATIENTS: 200 normal term newborns with echocardiographically normal hearts (median age 1.0 d) and 66 infants with critical congenital heart disease (CCHD; median age 3 d). METHODS: Pulse oximetry was performed in the right hand and one foot using a new-generation pulse oximeter (NGoxi) and a conventional-technology oximeter (CToxi). RESULTS: With the NGoxi, normal newborns showed a median postductal saturation of 99% (range 94-100%); intra-observer variability showed a mean difference of 0% (SD 1.3%), and inter-observer variability was 0% (SD 1.5%). The CToxi recorded a significantly greater proportion of postductal values below 95% (41% vs 1%) in the normal newborns compared with NGoxi (p<0.0001). The CCHD group showed a median postductal saturation of 90% (45-99%) with the NGoxi. Analysis of distributions suggested a screening cut-off of <95%; however, this still gave 7/66 false-negative patients, all with aortic arch obstruction. Best sensitivity was obtained by adding one further criterion: saturation of <95% in both hand and foot or a difference of >+/-3% between hand and foot. These combined criteria gave a sensitivity of 98.5%, specificity of 96.0%, positive predictive value of 89.0% and negative predictive value of 99.5%. CONCLUSION: Systematic screening for CCHD with high accuracy requires a new-generation oximeter, and comparison of saturation values from the right hand and one foot substantially improves the detection of CCHD.

Blood cardioplegia provides superior protection in infant cardiac surgery.

BACKGROUND: We hypothesized that blood cardioplegia preserves myocardial metabolism and function more effectively than St Thomas' crystalloid cardioplegia in infant cardiac surgery. METHODS: Thirty infants with atrioventricular septal defects were randomly allocated to either blood or crystalloid intermittent cold (4 degrees C) cardioplegia. Arterial and coronary sinus blood was analyzed for lactate and oxygen. Cardiac output (thermodilution) and left ventricular function (echocardiography) were evaluated. RESULTS: The lactate concentration in coronary sinus blood early after bypass was significantly higher after crystalloid cardioplegia than after blood cardioplegia (2.1 +/- 0.3 vs 1.3 +/- 0.1 mmol/L, p = 0.006), with a significant myocardial release of lactate after crystalloid but not after blood cardioplegia. Oxygen extraction (arterial-coronary sinus O2 content) was higher early after crystalloid cardioplegia (3.02 +/- 0.13 vs 2.35 +/- 0.22 mmol/L, p = 0.01), possibly reflecting a difference in oxygen debt. The cardiac index was higher after blood cardioplegia (4.9 +/- 0.3 vs 4.0 +/- 0.3 L/min(-1)/m(-2), p = 0.04) and echocardiographic grading of left ventricular function was better (4.1 +/- 0.17 vs 3.5 +/- 0.22 arbitrary units, p = 0.046). CONCLUSIONS: This study indicates that blood cardioplegia preserves myocardial metabolism and function more effectively than crystalloid cardioplegia in infant cardiac surgery. The clinical significance of this finding is uncertain, but the more than 20% increase in cardiac index in the critical phase during weaning from bypass may be advantageous.

Long-term survival in children with atrioventricular septal defect and common atrioventricular valvar orifice in Sweden.

BACKGROUND: The survival for patients with atrioventricular septal defect has improved markedly over the last decades and, during the same period, the survival of children with Down's syndrome has also increased. The aim of our study was to investigate long-term survival in patients having atrioventricular septal defect with common valvar orifice, but without associated significant congenital heart defects, in the setting of Down's syndrome, comparing the findings to those in chromosomally normal children with the same malformation. METHODS AND RESULTS: In a population-based retrospective study, we scrutinised the medical records from 801 liveborn children with atrioventricular septal defect born in Sweden during the period 1973 through 1997. Data on gender, presence or absence of Down's syndrome, associated congenital heart defects, date of birth, operation and death were recorded and followed up until 2001. An isolated atrioventricular septal defect with common atrioventricular valvar orifice was present in 502 children, of whom 86% had Down's syndrome. We found a significant reduc tion over time in age at operation, and in postoperative mortality at 30 days, from 28 to 1%. Using a multiple logistic regression model, we found no significant differences in mortality between genders, nor between those with or without Down's syndrome. Early corrective surgery could not be identified as a significant independent factor for survival. The 5-year postoperative survival in patients with Down's syndrome increased from 65% over the period from 1973 through 1977, to about 90% in the period 1993 through 1997, and the same trend was observed in chromosomally normal patients. CONCLUSIONS: Survival in uncomplicated atrioventricular septal defect with common atrioventricular valvar orifice has greatly increased, and surgical correction is now equally successful in patients with Down's syndrome and chromosomally normal patients, and for both genders. Death in connection with surgery is no longer the major threat, and focus must now be on long-term follow-up.