Volume overload impedes the maturation of sarcomeres and T-tubules in the right atria: a potential cause of atrial arrhythmia following delayed atrial septal defect closure.

Introduction: Adult patients with atrial septal defects (ASD), the most common form of adult congenital heart disease, often die of arrhythmias, and the immaturity of cardiomyocytes contributes significantly to arrhythmias. ASD typically induces a left-to-right shunt, which then leads to the right atrium (RA) volume overload (VO). Whether or not VO contributes to RA cardiomyocyte immaturity and thereby causes arrhythmias in adult patients with ASD remains unclear. Methods: Here, we developed the first neonatal RA VO mouse model by creating a fistula between the inferior vena cava and abdominal aorta on postnatal day 7. RA VO was confirmed by increases in the mean flow velocity, mean pressure gradient, and velocity time integral across the tricuspid valve, and an increase in the RA diameter and RA area middle section. Results: We found that VO decreased the regularity and length of sarcomeres, and decreased the T-element density, regularity, and index of integrity of T-tubules in RA cardiomyocytes, suggesting that the two most important maturation hallmarks (sarcomere and T-tubules) of RA cardiomyocytes were impaired by VO. Accordingly, the calcium handling capacity of cardiomyocytes from postnatal day 21 (P21) RA was decreased by VO. VO caused a significant elongation of the PR interval. The expression of connexin 43 (Cx43) was decreased in RA VO. Moreover, gene ontology (GO) analysis of the downregulated genes in RA demonstrated that there was an abundance of enriched terms associated with sarcomeres and T-tubules exposed to VO. The results were further verified by qRT-PCR. Conclusions: In conclusion, the first neonatal RA VO mouse model was developed; furthermore, using this neonatal RA VO mouse model, we revealed that VO impeded RA sarcomere and T-tubule maturation, which may be the underlying causes of atrial arrhythmias in adult patients with ASD.

A neonatal rat model of pulmonary vein stenosis.

OBJECTIVES: Pulmonary vein stenosis (PVS), one of the most challenging clinical problems in congenital heart disease, leads to secondary pulmonary arterial hypertension (PAH) and right ventricular (RV) hypertrophy. Due to the lack of a rodent model, the mechanisms underlying PVS and its associated secondary effects are largely unknown, and treatments are minimally successful. This study developed a neonatal rat PVS model with the aim of increasing our understanding of the mechanisms and developing possible treatments for PVS. METHODS: PVS was created at postnatal day 1 (P1) by banding pulmonary veins that receive blood from the right anterior and mid lobes. The condition was confirmed using echocardiography, computed tomography (CT), gross anatomic examination, hematoxylin and eosin (H&E) staining, fibrosis staining, and immunofluorescence. Lung and RV remodeling under the condition of PVS were evaluated using H&E staining, fibrosis staining, and immunofluorescence. RESULTS: At P21, echocardiography revealed a change in wave form and a decrease in pulmonary artery acceleration time-indicators of PAH-at the transpulmonary valve site in the PVS group. CT at P21 showed a decrease in pulmonary vein diameter in the PVS group. At P30 in the PVS group, gross anatomic examination showed pulmonary congestion, H&E staining showed wall thickening and lumen narrowing in the upstream pulmonary veins, and immunofluorescence showed an increase in the smooth muscle layers in the upstream pulmonary veins. In addition, at P30 in the PVS group, lung remodeling was evidenced by hyperemia, thickening of pulmonary small vessel walls and smooth muscle layers, and reduction of the number of alveoli. RV remodeling was evidenced by an increase in RV free wall thickness. CONCLUSIONS: A neonatal rat model of PVS was successfully established, showing secondary lung and RV remodeling. This model may serve as a useful platform for understanding the mechanisms and treatments for PVS.

Mitral intervention for anomalous left coronary artery from the pulmonary artery: midterm outcomes.

OBJECTIVES: Anomalous left coronary artery from the pulmonary artery (ALCAPA) is frequently associated with significant mitral regurgitation (MR). We aim to identify surgical outcomes in patients with or without concomitant mitral intervention. METHODS: All patients with ALCAPA who presented with >mild degree of MR at our institution between January 2008 and June 2020 were included in the retrospective study. MR recovery was defined as ≤mild MR at the last follow-up. RESULTS: The study cohort included 101 patients. The median age at repair was 7.6 months. The concomitant mitral intervention was performed in 66 patients (65%). MR grade significantly improved at the last follow-up. The cumulative incidence of MR recovery 3 years after ALCAPA repair was 34% [95% confidence interval (CI), 19-50%) in patients with mitral intervention, compared to 59% (95% CI, 41-73%) in patients without mitral intervention (P = 0.050). MR grade on postoperative day 1 was the predictor for MR recovery in patients with mitral intervention (hazard ratio, 0.080; 95% CI, 0.018-0.366; P = 0.001), whereas preoperative mitral annulus diameter z-score was the predictor in patients without mitral intervention (hazard ratio, 0.480; 95% CI, 0.232-0.993; P = 0.048). Freedom from mitral reoperation in patients with mitral intervention was 94% and 88% at 3 and 5 years after surgery, while freedom from mitral reoperation in patients without mitral intervention was 100% at both timepoints (P = 0.177). CONCLUSIONS: Despite significant MR improvement after ALCAPA repair, MR grade may not always return to normal regardless of the initial mitral management strategy, and reoperation for persistent MR is not rare.

Ability of the Right Ventricle to Serve as a Systemic Ventricle in Response to the Volume Overload at the Neonatal Stage.

BACKGROUND: In children with hypoplastic left heart syndrome (HLHS), volume overload (VO) is inevitable, and the right ventricle (RV) pumps blood into the systemic circulation. Understanding the molecular differences and their different responses to VO between the RV and left ventricle (LV) at the neonatal and highly plastic stages may improve the long-term management of children with HLHS. METHODS AND RESULTS: A neonatal rat ventricular VO model was established by the creation of a fistula between the inferior vena cava and the abdominal aorta on postnatal day 1 (P1) and confirmed by echocardiographic and histopathological analyses. Transcriptomic analysis demonstrated that some of the major differences between a normal neonatal RV and LV were associated with the thyroid hormone and insulin signaling pathways. Under the influence of VO, the levels of insulin receptors and thyroid hormone receptors were significantly increased in the LV but decreased in the RV. The transcriptomic analysis also demonstrated that under the influence of VO, the top two common enriched pathways between the RV and LV were the insulin and thyroid hormone signaling pathways, whereas the RV-specific enriched pathways were primarily associated with lipid metabolism and arrhythmogenic right ventricular cardiomyopathy (ARVC); further, the LV-specific enriched pathways were primarily associated with nucleic acid metabolism and microRNAs in cancer. CONCLUSIONS: Insulin and thyroid hormones may play critical roles in the differences between a neonatal RV and LV as well as their common responses to VO. Regarding the isolated responses to VO, the RV favors an ARVC change and the LV favors a reduction in microRNAs in cancer. The current study suggests that insulin, thyroid hormone, and cancer-associated microRNAs are potential therapeutic targets that should be explored by basic science studies to improve the function of the RV to match that of the LV.

Ross Procedure in the era of Handmade-Valved Conduits for Right Ventricular Outflow Tract Reconstruction in Children: Short-Term Surgical Outcomes.

Objective: Ross procedure is considered as the "gold standard" for aortic valve replacement, but the conduits used for right ventricular outflow tract (RVOT) reconstruction, such as homografts and bovine jugular vein (BJV) conduits, are of limited availability in China. Handmade expanded polytetrafluoroethylene-valved conduits (HVCs) have been used recently as the alternative for RVOT reconstruction, but their specific experience in Ross procedure is limited in the literature. Methods: This was a retrospective review of 27 children who underwent Ross procedure in our center from January 2018 to January 2022. Results: Mean age at surgery was 8.0 ± 3.8 years. During the study period, BJV conduits were used for RVOT reconstruction in 6 patients (22%), and HVCs were used in 21 patients (78%). Median conduit size was 20 mm (range, 16-24 mm), and mean conduit Z-score was +0.8 ± 0.9. Median time for cardiopulmonary bypass was 158 min (range, 109-275 min), and mean time for aortic crossclamping was 110 ± 21 min. There was no early mortality. During a median follow-up time of 1.4 years (range, 0.1-3.7 years), 3 patients (11%) with BJV conduits had peak conduit velocity of > 3.5 m/s; 3 patients (11%) with HVCs developed moderate conduit insufficiency; no patients had more than moderate conduit insufficiency. Three patients with BJV conduits had 5 reinterventions, and all received conduit replacement with HVCs. Conclusion: HVC is an appealing alternative to BJV conduit for RVOT construction for children undergoing Ross procedure, with favorable short-term outcomes.

Association Between Preoperative Factors and In-hospital Mortality in Neonates After Cardiac Surgery in China.

Background: Little is known about preoperative factors affecting cardiac surgery outcomes of neonates in China. We sought to examine the association between characteristics of neonates with congenital heart disease (CHD) and early postoperative outcomes after cardiac repair in a tertiary care paediatric hospital. Methods: A single-centre retrospective cohort study of neonates who underwent cardiac surgery between January 2006 and December 2019 was performed. Demographic, institutional, and surgical characteristics of neonates were examined and their association with in-hospital mortality was analysed using multivariable logistic regression models. Results: During the study period, we analysed the outcomes of 1,078 neonates. In-hospital mortality decreased to 13.8% in the era 2017-2019. The overall in-hospital mortality rate was 16.3%. Normal weight at surgery [odds ratio (OR), 0.63; 95% confidence interval (CI), 0.47-0.85; P = 0.003] was associated with lower mortality risk. Poor health status (emergent: OR, 3.11; 95% CI, 1.96-4.94; P < 0.001; elective: OR, 1.63; 95% CI, 1.11-2.40; P = 0.013), higher Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) categories (STAT 5 category: OR, 2.58; 95% CI, 1.04-6.43; P = 0.042), and limited individual surgeon experience (surgeon with 5-10 operations per year: OR, 1.43; 95% CI, 1.06-1.95; P = 0.021) were associated with higher odds of early death. Conclusion: In-hospital mortality after neonatal cardiac surgery remained high in our centre over the past 10 years. Some preoperative aspects, including low-weight at surgery, poor health status, increased surgical complexity, and limited surgeon experience were significantly associated with higher mortality. Based on the observed associations, the necessary practises to be modified, especially in preoperative care, should be identified and assessed in future research.

Downregulated developmental processes in the postnatal right ventricle under the influence of a volume overload.

The molecular atlas of postnatal mouse ventricular development has been made available and cardiac regeneration is documented to be a downregulated process. The right ventricle (RV) differs from the left ventricle. How volume overload (VO), a common pathologic state in children with congenital heart disease, affects the downregulated processes of the RV is currently unclear. We created a fistula between the abdominal aorta and inferior vena cava on postnatal day 7 (P7) using a mouse model to induce a prepubertal RV VO. RNAseq analysis of RV (from postnatal day 14 to 21) demonstrated that angiogenesis was the most enriched gene ontology (GO) term in both the sham and VO groups. Regulation of the mitotic cell cycle was the second-most enriched GO term in the VO group but it was not in the list of enriched GO terms in the sham group. In addition, the number of Ki67-positive cardiomyocytes increased approximately 20-fold in the VO group compared to the sham group. The intensity of the vascular endothelial cells also changed dramatically over time in both groups. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the downregulated transcriptome revealed that the peroxisome proliferators-activated receptor (PPAR) signaling pathway was replaced by the cell cycle in the top-20 enriched KEGG terms because of the VO. Angiogenesis was one of the primary downregulated processes in postnatal RV development, and the cell cycle was reactivated under the influence of VO. The mechanism underlying the effects we observed may be associated with the replacement of the PPAR-signaling pathway with the cell-cycle pathway.

Dexmedetomidine Protects Human Cardiomyocytes Against Ischemia-Reperfusion Injury Through α2-Adrenergic Receptor/AMPK-Dependent Autophagy.

Background: Ischemia-reperfusion injury (I/R) strongly affects the prognosis of children with complicated congenital heart diseases (CHDs) who undergo long-term cardiac surgical processes. Recently, the α2-adrenergic receptor agonist Dexmedetomidine (Dex) has been reported to protect cardiomyocytes (CMs) from I/R in cellular models and adult rodent models. However, whether and how Dex may protect human CMs in young children remains largely unknown. Methods and Results: Human ventricular tissue from tetralogy of Fallot (TOF) patients and CMs derived from human-induced pluripotent stem cells (iPSC-CMs) were used to assess whether and how Dex protects human CMs from I/R. The results showed that when pretreated with Dex, the apoptosis marker-TUNEL and cleaved caspase 3 in the ventricular tissue were significantly reduced. In addition, the autophagy marker LC3II was significantly increased compared with that of the control group. When exposed to the hypoxia/reoxygenation process, iPSC-CMs pretreated with Dex also showed reduced TUNEL and cleaved caspase 3 and increased LC3II. When the autophagy inhibitor (3-methyladenine, 3-MA) was applied to the iPSC-CMs, the protective effect of Dex on the CMs was largely blocked. In addition, when the fusion of autophagosomes with lysosomes was blocked by Bafilomycin A1, the degradation of p62 induced by Dex during the autophagy process was suspended. Moreover, when pretreated with Dex, both the human ventricle and the iPSC-CMs expressed more AMP-activated protein kinase (AMPK) and phospho AMPK (pAMPK) during the I/R process. After AMPK knockout or the use of an α2-adrenergic receptor antagonist-yohimbine, the protection of Dex and its enhancement of autophagy were inhibited. Conclusion: Dex protects young human CMs from I/R injury, and α2-adrenergic receptor/AMPK-dependent autophagy plays an important role during this process. Dex may have a therapeutic effect for children with CHD who undergo long-term cardiac surgical processes.

Single-institution outcomes of surgical repair of infracardiac total anomalous pulmonary venous connection.

OBJECTIVE: This contemporary study sought to describe the outcomes of patients undergoing biventricular repair of infracardiac total anomalous pulmonary venous connection. METHODS: A retrospective study was performed on patients with infracardiac total anomalous pulmonary venous connection who underwent sutureless technique or conventional repair between 2006 and 2018. Risk factors for survival and post-repair pulmonary vein stenosis (PVS) were assessed with Cox regression model. Time-to-event analysis was conducted using Kaplan-Meier estimates. RESULTS: This study included 82 consecutive patients with the median age of 21 days (interquartile range, 9-40 days). The median follow-up was 29 months (interquartile range, 12.5-59 months) and was available in 95% of the survivors at the end of the study period in 2019. Overall, 8 deaths (8.5%) occurred in the conventional repair group. There was a trend of higher mortality in the conventional repair group, although it did not reach a statistical difference (P = .2). Postrepair PVS occurred at a median of 2 months (interquartile range, 1.2-3.6 months) postoperatively and all occurred in the conventional repair group. Time-to-event analysis with the event of postrepair PVS showed significantly higher freedom from restenosis in the sutureless technique group (P = .0004). Adjusted hazard ratios from time-dependent Cox model described the association between postrepair PVS and pulmonary venous confluence of antler configuration (hazard ratio, 2.14; 95% confidence interval, 1.03-5.47; P = .002) and the use of sutureless technique (hazard ratio, 0.72; 95% confidence interval, 0.39-0.97; P = .003). CONCLUSIONS: Sutureless technique is associated with a lower risk of postrepair PVS in patients with infracardiac total anomalous pulmonary venous connection. pulmonary venous confluence configuration of antler appearance appears to be associated with restenosis and mortality.

Role of Blood Oxygen Saturation During Post-Natal Human Cardiomyocyte Cell Cycle Activities.

Blood oxygen saturation (SaO2) is one of the most important environmental factors in clinical heart protection. This study used human heart samples and human induced pluripotent stem cell-cardiomyocytes (iPSC-CMs) to assess how SaO2 affects human CM cell cycle activities. The results showed that there were significantly more cell cycle markers in the moderate hypoxia group (SaO2: 75% to 85%) than in the other 2 groups (SaO2 <75% or >85%). In iPSC-CMs 15% and 10% oxygen (O2) treatment increased cell cycle markers, whereas 5% and rapid change of O2 decreased the markers. Moderate hypoxia is beneficial to the cell cycle activities of post-natal human CMs.

Surgical treatment of mixed total anomalous pulmonary venous connection / 中国胸心血管外科临床杂志

@#Objective    To analyze the outcomes of surgical repair for mixed total anomalous pulmonary venous connection (TAPVC). Methods    Between 2006 and 2018, a total of 51 patients with mixed TAPVC underwent surgery in our hospital. Patients with such associated anomalies as single ventricle and tetralogy of Fallot were excluded. There were 35 males and 16 females with a median age of 102.0 (59.0, 181.0) days and a median weight of 5.0 (4.1, 6.4) kg. Patients were divided into three categories based on the anatomy: "3+1" pattern (n=38, three pulmonary veins drained at one site, and the other drained at the opposite site); "2+2" pattern (n=9, the pulmonary veins from each lung joined to form a confluence and drained at separate sites); bizarre pattern (n=4, the anatomy could not be classified into the above two patterns). Results    There was no in-hospital death. The median follow-up was 41.0 (18.0, 86.5) months. Postoperative pulmonary venous obstruction occurred in 10 patients. Kaplan-Meier survival curves showed no statistically significant difference in postoperative pulmonary venous obstruction among the three groups (P=0.239). Cox risk regression showed that preoperative pulmonary venous obstruction was significantly associated with postoperative pulmonary venous obstruction (P=0.024). Conclusion    Mixed TAPVC has various anatomic morphologies and requires individualized surgery.

Effects of hypoxia on cardiomyocyte proliferation and association with stage of development.

BACKGROUND: Hypoxia has been suggested to be both beneficial and harmful to the proliferation of cardiomyocytes. This controversy remains unresolved, and the underlying mechanism by which hypoxia exerts its effects remains unclear. We here hypothesize that cardiomyocyte developmental stage may play a role. METHODS AND RESULTS: The embryonic ventricular myocyte cell line H9C2, primary isolated fetal cardiomyocytes, and neonatal cardiomyocytes were cultured with normal O2 (21% O2) or under hypoxic conditions (10% O2) for 7 days, and then harvested for Western blotting, qRT-PCR, and immunostaining. When cultured under hypoxic conditions, proliferating marker-Ki67, mRNA level, and the percentage of Ki67-positive cardiomyocytes were significantly lower in H9C2 and fetal cardiomyocytes but higher in neonatal cardiomyocytes. Consistently, the mRNA and protein levels and induced nuclear localization of yes associated protein 1(YAP1), one of the most important regulators of cardiomyocyte proliferation, were significantly lower in H9C2 and fetal cardiomyocytes but up-regulated in neonatal cardiomyocytes when treated with hypoxia. Compared to neonatal cardiomyocytes, there was a lower level of troponin T mRNA and protein expression in H9C2 and fetal cardiomyocytes. When H9C2 or fetal cardiomyocytes overexpressing troponin T in were cultured under hypoxic condition, their ability to proliferate increased. CONCLUSIONS: The effect of hypoxia on the proliferation of cardiomyocyte is associated with their developmental stage. YAP1 expression is positively correlated with the change in cardiomyocyte proliferation in response to hypoxia. Developmental stage- specific sarcomere component troponin T may partly account for the underlying mechanism.

Outcomes of Prosthetic Valved Conduits for Right Ventricular Outflow Tract Reconstruction.

There are limited data regarding the implantation of prosthetic valved conduits for right outflow tract reconstruction in pediatric patients in China. A retrospective review of 128 patients undergoing conduits implantation with a median follow-up of 33.3 months (range, 3.3 months to 10.1 years) was performed between 2009 and 2018. Multivariate Cox regression model was used to analyze the risk factors for mortality, reintervention and endocarditis. Freedom from reintervention and endocarditis were plotted using the Kaplan-Meier curve. Hospital mortality was 7.8%, and the late mortality was 3.1%. Patient survival at 1, 5 and 10 years was 92.2%, 87.1% and 84.3%, respectively. Freedom from reintervention at 1 and 5 years was 94.1% and 60.9%. Small size conduit (p = 0.019) and previous palliation (p < 0.001) were predictive of reintervention. Ten conduits developed endocarditis at a median of 4.8 years after implantation. Freedom from endocarditis at 1, 5 and 10 years was 99.1%, 93.0% and 58.0%, respectively. Diffuse stenosis of the conduit (p = 0.003) was an independent risk factor for late endocarditis. Both bovine jugular venous conduits and bovine pericardial prosthetic conduits are associated with acceptable outcomes. Reintervention remains high in patients who have smaller size conduit and undergo previous palliation. It is plausible that the suboptimal flow may be one of major mechanisms involved in the development of late endocarditis.

Dexmedetomidine protects mice against myocardium ischaemic/reperfusion injury by activating an AMPK/PI3K/Akt/eNOS pathway.

Acute myocardial ischaemia/reperfusion (MIR) injury leads to severe arrhythmias and has a high rate of lethality. In the present study, we aim to determine the effect of dexmedetomidine (Dex) on heart injury parameters following MIR surgery. We examined the effects of Dex on heart function parameters and infarct size following MIR surgery. Proinflammatory cytokines, oxidative products and anti-oxidative enzymes in the myocardium were measured to evaluate the anti-inflammatory and anti-oxidative effects of Dex. The role of the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/phosphatidylino-sitol 3-kinase (PI3k)/Akt/endothelial nitric oxide synthase (eNOS) pathway was investigated using their inhibitors. The alteration of haemodynamic parameters, histopathological results, and infarct size caused by MIR was attenuated by Dex. The interleukine-1 beta (IL-1ß), IL-6, tumour necrosis factor-a (TNF-α) and myeloperoxidase (MPO) were all significantly decreased. Anti-oxidative enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) were restored by Dex. Oxidative products8-OHdG, MDA and protein carbonyl were all decreased by Dex (P<.05). Dex activated AMPK expression, eNOS and Akt phosphorylation. The influence of Dex on cardiac function was reversed by the inhibitors of the eNOS, AMPK and PI3K/Akt pathways. These results indicate that Dex protected the cardiac functional, histological changes, inflammation and oxidative stress induced by MIR. Our results present a novel signalling mechanism that Dex protects MIR injury by activating an AMPK/PI3K/Akt/eNOS pathway.

Cardiomyocytes in Young Infants With Congenital Heart Disease: a Three-Month Window of Proliferation.

Perinatal reduction in cardiomyocyte cell cycle activity is well established in animal models and humans. However, cardiomyocyte cell cycle activity in infants with congenital heart disease (CHD) is unknown, and may provide important information to improve treatment. Human right atrial specimens were obtained from infants during routine surgery to repair ventricular septal defects. The specimens were divided into three groups: group A (age 1-3 months); group B (age, 4-6 months); and group C (age 7-12 months). A dramatic fall in the number of Ki67-positive CHD cardiac myocytes occurred after three months. When cultured in vitro, young CHD myocytes (≤ 3 months) showed more abundant Ki67-positive cardiomyocytes and greater incorporation of EdU, indicating enhanced proliferation. YAP1 and NICD-important transcript factors in cardiomyocyte development and proliferation-decreased with age and ß-catenin increased with age. Compared with those of older infants, cardiomyocytes of young CHD infants (≤ 3 months) have a higher proliferating capacity in vivo and in vitro. From the perspective of cardiac muscle regeneration, CHD treatment at a younger age (≤ 3 months) may be more optimal.

Treatment Strategies for Primary Tumors of the Heart in Children: A 10-Year Experience.

BACKGROUND: The goal of this study was to determine the optimal treatment strategy for children with primary tumors of the heart. METHODS: We reviewed 88 children with primary heart tumors in our center from January 2004 to December 2013. Operative patients were followed every 6 months in the first postoperative year and then regularly every 12 months; nonoperative patients were followed once a year after diagnosis. Demographic information of imaging, operative details, and postoperative data were obtained from medical records. Statistical analyses were carried out by means of Fisher's exact tests and Student's t test. RESULTS: Of the 23 patients who underwent surgical removal of the tumors (range, 12 days to 14.4 years; median, 1.3 years), 19 patients had stable postoperative hemodynamics, 4 had low cardiac output, and 2 patients died (mortality, 9%). The follow-up ranged from 6 months to 9 years; 2 patients had tumor recurrence, and 1 patient was lost to follow-up. The rest of the operative patients remained in normal sinus rhythm and had normal cardiac function. The 65 patients treated nonoperatively (range, 1 day to 14.4 years; median, 0.4 years) were followed closely for 1 month to 9.8 years; only 1 patient died (of unknown reasons), 1 patient received a cardiac transplant, and 9 patients were lost to follow-up. CONCLUSIONS: Operative resection is optimal for primary tumors of the heart in patients with obvious symptoms or hemodynamic changes. Rhabdomyomas have the potential for spontaneous regression, and nonoperative follow-up therefore is acceptable even if symptoms appear. Operative risk is greater in younger patients and in patients with cardiac valvular dysfunction.

[The left ventricular assistance device was used for anomalous origin of the left coronary artery from the pulmonary artery in perioperative period].

OBJECTIVE: To review the experience of left ventricular assistance device (LVAD) using for anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) in perioperative period. METHODS: There were 29 patients with ALCAPA underwent surgical repair from May 2006 to May 2013. The mean age was 6.5 months (ranging from 3.3 to 12.1 months). The mean weight was 6.2 kg (ranging from 4.1 to 9.5 kg). Diagnosis was established by echocardiography in all patients. There were clinical symptomatic of the severe heart dysfunction and ejection fraction were 23% to 45%. Mitral insufficiency was moderate to severe in 8 patients and less than moderate in others. Surgical methods included the intrapulmonary tunnel (Takeuchi procedure) of 4 cases, direct reimplantation of the left coronary artery onto the aorta of 6 cases and reimplantation by pericardiac patch enlarge of 19 cases. Valvuloplasty were performed in 5 patients with mitral severe insufficiency. Twenty-two patients were treated only by medicine therapy. LVAD was used in 7 patients: there were 3 patients with low blood pressure at the end of surgical repair and 4 patients with low cardio output within 24 hours postoperatively. RESULTS: Postoperatively, transesophageal echocardiography demonstrated that blood flow of the left coronary artery is fluently but left ventricular is also largement. The hemodynamic of 18 patients was stable in medicine group but 3 patients were sudden died of low cardiao output and ventricular fibrillation respectively. One patient was died of diffuse intravascular coagulation at the time of 72 hours after operation. The hemodynamic was stable in 6 patients in LVAD group and the devices after using time from 72 to 108 hours was taken down except one patient died of multi-organ dysfunction. The hospital mortality was 5/29 (17.2%). Nineteen survival (19/24) was followed up of 3.5 years (ranging from 1 to 7 years). Reoperations was performed for one patient with the supravalvar pulmonary stenosis due to the Takeuchi procedure 4 years postoperatively. Echocardiographic demonstrated that the blood flow of the left coronary artery are fluently. Mitral insufficiency was moderate in 2 cases, mild to moderate in 9 cases and mild in 8 cases. The ejection fraction value were 43% to 55% and apparent arrhythmia didn't occur. CONCLUSIONS: Although late results are satisfactory and left ventricular function always recovery, early mortality is higher even though the protective methods are carried out during the whole cardiopulmonary bypass procedure. In order to decrease the early mortality, heart function evaluation and LVAD should be used as an effective cardiac support technique to prevent heart failure in time.

Over-expression of HSPA12B protects mice against myocardium ischemic/reperfusion injury through a PPARγ-dependent PI3K/Akt/eNOS pathway.

Acute myocardial ischemia/reperfusion (MIR) injury leads to severe arrhythmias and a high lethality. We aim to determine the effect of heat shock protein A12B (HSPA12B), a newly discovered member of the Hsp70 family, on heart injury parameters following MIR surgery. We used HSPA12B transgenic mice to determine its effects on heart function parameters, infarct size and cellular apoptosis following MIR surgery. Proinflammatory cytokines, oxidative products and anti-oxidative enzymes in the myocardium were measured to evaluate the anti-inflammatory and anti-oxidative effects of HSPA12B over-expression. The role of PPARs/eNOS/PI3k/Akt pathway was investigated using their inhibitors. The alteration of hemodynamic parameters, histopathological, apoptotic and infarct size caused by MIR was greatly attenuated in HSPA12B over-expressed mice. HSPA12B also greatly mitigated the inflammatory response, demonstrated by the decrease in the levels of IL-1ß, IL-6, TNF-a and MPO. Anti-oxidative enzymes (SOD, Catalase and GPx) were restored by HSPA12B; oxidative products (8-OHdG, MDA and protein carbonyl) were decreased. HSPA12B activated the PPARγ-dependent eNOS/PI3k/Akt pathway, and the influence of HSPA12B on cardiac function was reversed by the inhibitors of eNOS, PPARγ, Akt and PI3K. Our results present a novel signaling mechanism that HSPA12B protects MIR injury through a PPARγ-dependent PI3K/Akt/eNOS pathway.

[Surgical repair of truncus arteriosus in children: early results and long-term outcomes].

OBJECTIVE: To recite early results and long-term outcomes after surgical repair of persistent truncus arteriosus (PTA). METHODS: The clinic data of 54 patients underwent surgical repair for PTA from January 1999 to December 2009 was analyzed retrospectively. There were 36 male and 18 female patients, with a mean age of (9 ± 10) months (range, 1 to 38 months; median, 5 months). Preoperative mechanical ventilation was required in 5 patients. The surgical procedures were closure of ventricular septal defect and re-establishment of continuity between right ventricle and pulmonary artery. The right ventricular outflow tract (RVOT) was reconstructed by direct anastomosis pulmonary artery to right ventriculotomy with anterior wall patch enlargement (28 cases), or by inserting conduits (26 cases). Valvuloplasty were performed in 4 patients with truncal valves moderate to severe insufficiency and aortoplasty in 3 patients with interrupted aortic arch (IAA). RESULTS: There were 3 patients (5.6%) died of pulmonary hypertensive crisis in hospital. The mean duration of ventilation was 6.8 days in 5 patients who were intubated before operation, while the others were 3.6 days. Forty-seven (92.2%) patients were followed-up for mean (6.8 ± 2.5) years (from 2.5 to 11.0 years). There were 2 patients with mild to moderate aortic regurgitation. One patient with aortic arch obstruction underwent balloon dilatation 2 years postoperatively. Among those patients who underwent direct anastomoses, 8 (32.0%) patients had pulmonary branch stenosis at 7 months to 1.5 years postoperatively, 12 (48.0%) patients were freedom from surgical reintervention 5.0 to 11.0 years postoperatively. Among those inserting conduits, 7 patients (31.8%) had conduit stenosis at 2.8 to 7.0 years after operation. Reoperations were performed for RVOT in 15 patients and there was no mortality. CONCLUSIONS: It is difficult to treat the PTA patients with IAA, intra-mural coronary artery or mechanical ventilation support before operation. The technique of direct anastomosis between pulmonary artery and right ventricle offers the potential growth for RVOT, but bilateral pulmonary branch stenosis may be occurred at earlier period of postoperation in some patients.

[Treatment strategies for pediatric patients with primary cardiac tumors].

OBJECTIVE: To analyze the experience of treatment strategies for pediatric patients with primary cardiac tumors. METHODS: The clinical data of 27 patients with primary cardiac tumors which detected by echocardiography from May 1999 to May 2009 was analyzed retrospectively. There were 20 male and 7 female patients, aged from 24 d to 12.6 years. There were 59.2% less than 1 year old at the time of diagnosis. A single tumor were present in 22 cases and multiple in 5 cases. Surgery was performed for 22 patients due to the varied significant symptoms such as arrhythmia, pericardial effusion, swoon and congestive heart failure with dyspnoea. Five patients were discharged hospital without surgical treatment. The surgical approaches were adopted according to tumor location. Complete surgical resection was performed in 14 patients and partial resection in 8 patients. Seven patients were underwent valve reconstruction, 5 involving the mitral valve and 2 involving the tricuspid valve. RESULTS: Histologic examination of the surgically resected tumors showed rhabdomyomas in 8 cases, fibromas in 5 cases, hemangiomas 3 cases, myxomas in 4 cases, fibrosarcoma in 1 case and yolk sac sarcoma in 1 case. Sixteen cases revealed stable haemodynamic status postoperative. Two cases occurred apparent symptoms of low cardiac output and significant arrhythmias, finally recovery after comprehensive treatment of restoration the heart function. There was a total of 4 patients in-hospital death following surgery due to multiorgan system failure. Of the 18 patients who survived after the surgery were followed up from 1 to 10 years, echocardiography showed the residual mass of the tumor with partial resection, rhabdomyoma diminishing in 2 patients and almost vanishing in 1 patient. The residual mass of one fibrosarcoma patient and one hemangioma patient were not increased. Patients with myxomas had no recur or systemic embolisation after the initial surgery. Five nonsurgical patients were followed up from 1 to 3 years, 2 patients without haemodynamic alterations, 1 patients with giant tumor of left ventricular free wall was died of arrhythmia, the other one was alive; the patient of multiple cardiac tumor with low cardiac output was died of heart failure. CONCLUSIONS: Despite the benign histology of most paediatric primary cardiac tumours, there may be significant associated with morbidity and occasional mortality. Therapy strategies should be individualised: surgery is indicated in cases with significant clinical symptoms and close follow-up is necessary for asymptomatic patients. Total resection is not the only therapeutic aim. Most important is the restoration of the normal haemodynamic heart function.