Severe hypoxemia after radiofrequency ablation for atrial fibrillation in palliatively repaired tetralogy of Fallot: A case report

BACKGROUND Patients with tetralogy of Fallot(TOF)often have arrhythmias,commonly being atrial fibrillation(AF).Radiofrequency ablation is an effective treatment for AF and does not usually cause severe postoperative hypoxemia,but the risk of complications may increase in patients with conditions such as TOF.CASE SUMMARY We report a young male patient with a history of TOF repair who developed severe hypoxemia after radiofrequency ablation for AF and was ultimately confirmed to have a new right-to-left shunt.The patient subsequently underwent atrial septal occlusion and eventually recovered.CONCLUSION Radiofrequency ablation may cause iatrogenic atrial septal injury;thus possible complications should be predicted in order to ensure successful treatment and patient safety.

Calcium-chelating peptides from rabbit bone collagen:characterization,identification and mechanism elucidation

This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.

Genome-edited rabbits:Unleashing the potential of a promising experimental animal model across diverse diseases

Animal models are extensively used in all aspects of biomedical research,with substantial contributions to our understanding of diseases,the development of pharmaceuticals,and the exploration of gene functions.The field of genome modification in rabbits has progressed slowly.However,recent advancements,particularly in CRISPR/Cas9-related technologies,have catalyzed the successful development of various genome-edited rabbit models to mimic diverse diseases,including cardiovascular disorders,immunodeficiencies,agingrelated ailments,neurological diseases,and ophthalmic pathologies.These models hold great promise in advancing biomedical research due to their closer physiological and biochemical resemblance to humans compared to mice.This review aims to summarize the novel gene-editing approaches currently available for rabbits and present the applications and prospects of such models in biomedicine,underscoring their impact and future potential in translational medicine.

Single-Cell RNA Sequencing Reveals Potential for Endothelial-to-Mesenchymal Transition in Tetralogy of Fallot

Background:Tetralogy of Fallot(TOF)is a very common cyanotic congenital heart disease.Endothelial-to-mesenchymal transition(EndoMT)is recognized as a physiological mechanism involved in embryonic heart development and endothelial formation.However,there is still a gap in the reports related to the mechanism of EndoMT development in TOF.Methods:First,transcriptomic data of single cell nuclei of TOF and Donor were obtained based on the Gene Expression Omnibus(GEO)database,and the data were normalized and clus-tered by dimensionality reduction using the Seurat package.Subsequently,differentially expressed genes(DEGs)between TOF and Donor were screened using the“FindMarkers”function,and the gene sets of interest were enriched.Finally,to characterize the dynamics of EndoMT occurrence in TOF,we performed pseudotime cell tra-jectory inference as well as utilized SCENIC analysis to probe the gene regulatory networks(GRNs)dominated by transcription factors(TFs)in endothelial cells.Results:We identified a total of six cell clusters based on single-cell nuclear transcriptome data from TOF and Donor.We found that 611 genes with up-regulated expression within TOF showed conversion to mesenchyme.By subdividing endothelial cell subtypes,endothelial cells 2 were shown to be involved in cell adhesion,migration and extracellular matrix processes.Pseudo-time and SCENIC analyses showed that endothelial cell 2 has EndoMT potential.In addition,ERG and TEAD1 are TFs that play key reg-ulatory roles in this subtype,and both of their target genes are also highly expressed in TOF.This demonstrates that ERG and TEAD1 effectively promote the EndoMT process.Conclusion:Our study reveals the molecular mechanisms underlying the development of EndoMT in TOF,which demonstrates that manipulating the endothelial-to-mesenchymal transition may offer unprecedented therapeutic potential for the treatment of TOF.

Pulmonary and tricuspid regurgitation after Tetralogy of Fallot repair: A case report

BACKGROUND Tetralogy of Fallot(TOF)is one of the most common congenital heart defects,and surgery is the primary treatment.There are no precise guidelines on the treatment protocol for tricuspid regurgitation(TR)as a common complication of TOF repair.The timing for treatment in patients presenting with valve regurgitation after TOF repair is often difficult to determine.Here,we report the first case of sequential treatment of pulmonary and TR using interventional therapy.CASE SUMMARY We present the case of a 52-year-old female patient,who had a history of TOF repair at a young age.A few years later,the patient presented with pulmonary and tricuspid regurgitation.The symptoms persisted and TR worsened following percutaneous pulmonary valve implantation.Preoperative testing revealed that the patient’s disease had advanced to an intermediate to advanced stage and that her general health was precarious.Because open-heart surgery was not an option for the patient,transcatheter tricuspid valve replacement was suggested.This procedure was successful,and the patient recovered fully without any adverse effects.This case report may serve as a useful resource for planning future treatments.CONCLUSION Treatment of both valves should be considered in patients with tricuspid and pulmonary regurgitations following TOF repair.The interventional strategy could be an alternative for patients with poor general health.

Pulmonary Hypertension Crisis in Patient with Tetralogy of Fallot and Mixed Total Anomalous Pulmonary Vein Connection after the Primary Correction:A Rare Case Report

Tetralogy of Fallot(TOF)with total anomalous pulmonary vein connections(TAPVC)is a rare type of complex congenital heart disease among all TOF cases.Co-presentation of major aortopulmonary collateral arteries(MAPCAs)compensates for the lack of central pulmonary bloodflow and decreases the severity of right-to-left shunting in TOF.We present a case of a 2-year-old child with complex diagnoses of TOF,TAPVC,a large secun-dum atrial septal defect(ASD),and intraoperatively identified MAPCAs.She underwent surgery to repair the TAPVC,valve-sparing reconstruction of the right ventricular outflow tract,interventricular defect closure,and the creation of patent foramen ovale(PFO).After the operation,hemodynamic instability happened along with sudden blood pressure drop,desaturation,and increased central venous pressure,which subsided after adminis-tering inhalational nitric oxide(NO).A postoperative pulmonary hypertension crisis was suggested when the patient experienced recurrent symptoms after the termination of NO.Echocardiographicfindings of a D-shaped left ventricle(LV),right-to-left PFO shunt and high tricuspid valve gradientfirmly established the diagnosis.It was subsequently managed with continuous NO inhalation and sildenafil,which rendered a satisfactory outcome.Repaired TOF and TAPVC could be at particular risk of developing pulmonary hypertension crisis,especially in the presence of MAPCAs due to possible remodeling of the pulmonary vasculature.Furthermore,a relatively non-compliant LV function and small left atrial size may exacerbate the risk of developing postcapillary pulmonary hypertension after TAPVC repair.A successful postoperative outcome calls for a meticulous preoperative analysis of the anatomical lesions,as well as careful monitoring.

Effects of Incorporating Mango (Mangifera indica), Avocado (Persea americana) and Guava (Psidium guajava) Leaves Powder in the Ration on Growth Characteristics in Rabbits

A study conducted on burgundy rabbits evaluated the effects of rations containing mango (Mangifera indica), avocado (Persea americana) and guava (Psidium guajava) powder. For this purpose, 36 rabbits (20 males and 16 females) aged 60 to 70 days with an average weight of 1012 ± 133 g were divided randomly into 4 equal groups (T0, T1, T2 and T3) of 9 animals each according to body weight (bw). The rabbits were divided throughout the trial, the animals were fed, those of group T0 (control) with a standard feed without any type of leaf powder, while those of groups 1, 2 and 3 received the standard feed supplemented with Mangifera indica, Persea americana and Psidium guajava leaves powder at the rate of 0.5% respectively. After two months of treatment, the animals were fasted for 12 hours (20 h - 8 h) and sacrificed to evaluate carcass and digestive organ weights. The results revealed that the values of feed intake, live weight and weight gain were non-significantly (p > 0.05) increased in all animals regardless of the ration in reference to the control. The different leaves powder induced an increase in carcass yield in rabbits but this increase was only significant (p M. indica leaf powder (51.03 ± 0.24) as compared to the control (48.63 ± 0.74). Gut length was significantly increased in animals fed rations containing Psidium guajava and Persea americana leaves powder compared to the control. A significant increase in gut weight was observed in animals fed the Persea americana leaf supplemented ration. In general, mango leaf powder performed better than other types of powders.

Methods to Reduce the Hypoglycemic Mortality of Alloxan in Diabetic Rabbit Model

Objective: To explore an intervention method to reduce the mortality of alloxan diabetes model, and to preliminarily analyze the mechanism of alloxan induced animal death. Methods: Healthy New Zealand rabbits were randomly divided into injection group, control group, experimental group and blank group. The single injection group was injected with 100 mg/kg alloxan once. The control group was given 5% glucose solution and 100 mg/kg alloxan was injected in two times. The experimental group was given 5% glucose solution orally, 100 mg/kg alloxan, 7 mL 0.9% NaCl intravenously and 5 mL 5% glucose intraperitoneally immediately, and blood glucose was continuously monitored, 10 mL 5% glucose intravenously and 10 mL 5% glucose intraperitoneally every 4 h in the hypoglycemic stage. The blank group does nothing. Liver and kidney tissues at different time periods were stained with HE and organ index was evaluated. Results: 1) A single injection of 100 mg/kg alloxan without any intervention resulted in 100% mortality. Before modeling, oral administration of 5% glucose solution, divided into two injections of 100 mg/kg alloxan, mortality reached 100%;A single injection of 100 mg/kg alloxan and continuous intervention of normal saline and glucose for 20 h can significantly reduce the mortality of alloxan induced diabetic rabbit model. 2) Liver and kidney tissues were damaged in different degrees at different time periods, and liver and kidney indexes were significantly increased after alloxan injection compared with the normal group, with statistical significance (P > 0.05). Conclusion: 1) Every 4 hours of hypoglycemia, 10 ml 5% glucose was injected intravenously 10 ml 5% glucose intraperitoneally. It can reduce the death rate of alloxan diabetic rabbit model and shorten the time of blood glucose measurement. 2) After the injection of alloxan, acute lesions of liver and kidney may occur in different degrees, or one of the causes of acute death of experimental animals.

Effects of Carrot (Daucus carota) Leaves Powder on Reproductive and Growth Characteristics of Rabbit (Oryctolagus cuniculus) Does

The present study was conducted to evaluate the effects of carrot leaf powder in the diet on reproductive and growth characteristics in rabbits. Thirty sexually matured rabbits does of 8 months old, 3.00 to 3.20 kg, were divided into three groups of 10 rabbits each, which were comparable in terms of body weight. Throughout the experiment, the rabbits of group 1 (control group) were fed ad libitum with a feed not containing carrot leaf powder (control ration), while those of groups 2 and 3 received the control ration supplemented with carrot leaf powder in concentrations of 0.5% and 1% respectively. Data was collected on feed intake, weight gain, receptivity, fertility, gestation length of does, litter size, weight, viability and sex ratio of the young rabbits till 5 weeks post-partum. There was no significant (P > 0.05) difference in the fertility rate, gestation duration and sex ratio of the kits with reference to the control. Litter size at birth was not significantly (P > 0.05) influenced in does fed diets containing carrot leaf powder compared to the control. However, the reversed effects were observed at five weeks post-partum. The live weight of weaned kits and weight gain of rabbit does at birth were significantly (P < 0.05) increased in treated rabbits compared to the control. The supplementation of carrot leaf powder in feed can improve production performance in female rabbits, through their antioxidant activities thanks to their various components, thus fighting against oxidative stress effects to which animals are exposed both from endogenous and environmental sources.

Betaine addition to the diet alleviates intestinal injury in growing rabbits during the summer heat through the AAT/mTOR pathway

Background The aim of this experiment was to investigate the effect of different levels of betaine(Bet)inclusion in the diet on the intestinal health of growing rabbits under summer heat.A total of 100 weaned Qixing meat rabbits aged 35 d with body weight of 748.61±38.59 g were randomly divided into 5 treatment groups:control group(basal diet)and Bet groups(basal diet+0.75,1.0,1.5 or 2.0 g/kg Bet).The average daily temperature in the rabbitry during the experiment was 30.48°C and the relative humidity was 69.44%.Results Dietary addition of Bet had no significant effect on growth performance and health status of growing rabbits(P>0.05),but it increased ileal secretory immunoglobulin A content compared to the control under summer heat(P<0.05).Addition of 0.75 g/kg Bet up-regulated jejunal IL-4,down-regulated ileal TNF-αexpression(P<0.05).The addition of 1.0 g/kg Bet increased the villi height(VH)in the jejunum(P<0.05).Serum glucose levels were reduced,and the expression of SLC6A20 was up-regulated in jejunum and ileum of rabbits fed with 1.5 g/kg Bet(P<0.05).When added at 2.0 g/kg,Bet reduced serum HSP70 content,increased jejunal VH,and up-regulated duodenal SLC7A6,SLC38A2,mTOR and 4EBP-2 expression(P<0.05).Correlation analysis revealed that intestinal mTOR expression was significantly and positively correlated with SLC7A6,SLC38A2,SLC36A1 and IL-4 expression(P<0.05).Conclusions Dietary addition of Bet can up-regulate the expression of anti-inflammatory factors through the AAT/mTOR pathway,improve the intestinal immune function,alleviate intestinal damage in growing rabbits caused by summer heat,and improve intestinal health.

Chemical Composition of Pineapple Press Residues (Ananas comosus) and Effect on Growth Performance of Rabbit (Oryctolagus cuniculus)

With a view to improving rabbit production performance, a trial on the chemical composition of pineapple press residue (Ananas comosus) and the effect of its incorporation in the ration on rabbit growth performance (Oryctolagus cuniculus) was carried out at the KUATE Cunicole Farm in Bandjoun, in Western Cameroon. To do this, 36 rabbits of the local breed, aged 53 days with an average weight of 1337 ± 119 g were distributed and randomly assigned to 3 experimental rations corresponding respectively to treatments or batches T0, T1 and T2. The animals in treatment T0 received a ration containing no pineapple press residue, while those in treatments T1 and T2 received a ration containing 20% and 40% pineapple press residue, respectively. These residues were dried and ground for chemical composition analysis. The feed served as well as refusals from the previous day were weighed each morning to assess feed intake. The animals were weighed every 7 days to assess weight performance. At the end of the trial which lasted 7 weeks, the animals were fasted for 24 hours, then sacrificed to evaluate carcass characteristics and the relative weights of some digestive organs. The results of this study showed that pineapple press residues had a high crude fiber content (19.2%) and energy (2500 Kcal/kg DM). Their incorporation had no significant effect on feed intake and feed conversion ratio. The average live weight, weight gain and average daily weight gain of the animals receiving the ration with 20% inclusion of pineapple press residue were comparable to those of the control group and significantly higher than those of animals fed with 40% inclusion of pineapple residue. The highest carcass yields were obtained with rabbits fed 20% pineapple press residue in their ration. The cost of feed for the production of a kilogram live weight of rabbit tends to decrease with the ration incorporated with 20% pineapple press residue. Pineapple press residues constitute a by-product that can be recycled and their incorporation at 20% can increase rabbit growth performance and reduce production costs.

An Improved Artificial Rabbits Optimization Algorithm with Chaotic Local Search and Opposition-Based Learning for Engineering Problems and Its Applications in Breast Cancer Problem

Artificial rabbits optimization(ARO)is a recently proposed biology-based optimization algorithm inspired by the detour foraging and random hiding behavior of rabbits in nature.However,for solving optimization problems,the ARO algorithm shows slow convergence speed and can fall into local minima.To overcome these drawbacks,this paper proposes chaotic opposition-based learning ARO(COARO),an improved version of the ARO algorithm that incorporates opposition-based learning(OBL)and chaotic local search(CLS)techniques.By adding OBL to ARO,the convergence speed of the algorithm increases and it explores the search space better.Chaotic maps in CLS provide rapid convergence by scanning the search space efficiently,since their ergodicity and non-repetitive properties.The proposed COARO algorithm has been tested using thirty-three distinct benchmark functions.The outcomes have been compared with the most recent optimization algorithms.Additionally,the COARO algorithm’s problem-solving capabilities have been evaluated using six different engineering design problems and compared with various other algorithms.This study also introduces a binary variant of the continuous COARO algorithm,named BCOARO.The performance of BCOARO was evaluated on the breast cancer dataset.The effectiveness of BCOARO has been compared with different feature selection algorithms.The proposed BCOARO outperforms alternative algorithms,according to the findings obtained for real applications in terms of accuracy performance,and fitness value.Extensive experiments show that the COARO and BCOARO algorithms achieve promising results compared to other metaheuristic algorithms.

Evaluation of Right Ventricular Global Longitudinal Function in Patients with Tetralogy of Fallot by Two-dimensional Ultrasound Speckle Tracking Imaging

Quantification of right ventricular(RV)volume and function remains a challenge because of RV complex geometry by conventional echocardiography.The purpose of this study was to assess RV global longitudinal function in patients with tetralogy of Fallot(TOF)by 2-dimensional ultrasound speckle tracking imaging(STI).Thirty-eight patients with TOF were enrolled in this study and divided into child group(n=25)and adult group(n=13)according to age.Thirty-eight age-and sex-matched normal subjects were selected as c...

Anomalous origin of left pulmonary artery branch from the aorta with Fallot's tetralogy:one case report

We report the case of a ten-year-old boy who had often presented with respiratory distress since born. Chest X-ray showed an enlarged right ventricle. Echocardiography demonstrated characteristic features of Fallot＇s tetralogy and the left pulmonary artery could not be visualized. However, cardiac catheterization disclosed that the left pulmonary artery had an anomalous origin in the ascending aorta. The patient underwent total surgical correction of the defects. Nine days later, he was discharged. We present the results of a literature review of the incidence, physiopathological, clinical, diagnostic, and surgical characteristics of this rare disease.

Improving Right Ventricle Cardiac Function for Repaired Tetralogy of Fallot Patient with Contracting Bands: A Modelling Study

Objective Patients with repaired tetralogy of Fallot(rTOF)account for the majority of cases with late onset right ventricle(RV)failure.The current surgical approach,including pulmonary valve replacement/insertion(PVR),has yielded mixed results with some patients recover RV function and some do not.An innovative surgical approach was proposed to help ventricle to contract and improve RV function qualified by ejection fraction with one or more active contracting bands.Computational biomechanical modelling is a widely used method in cardiovascular study for investigation of mechanisms governing disease development,quantitative diagnostic and treatment strategies and improving surgical designs for better outcome.Muscle active contraction caused by zero-load sarcomere shortening leads to change of zero-load configurations.In lieu of experimenting using real surgery on animal or human,computational simulations(virtual surgery)were performed to test different band combination and insertion options to identify optimal surgery design and band insertion plan.Methods Cardiac magnetic resonance(CMR)data were obtained from one rTOF patient(sex:male,age:22.5 y)before pulmonary valve replacement surgery.The patient was suffering from RV dilation and dysfunction with RV end-systole volume 254.49ml and end-diastole volume 406.91 mL.A total of 15 computational RV/LV/Patch/Band combination models based on(CMR)imaging were constructed to investigate the influence of different band insertion surgery plans.These models included 5 different band insertion models combined and 3 different band contraction ratio(10%,15%and 20%band zero-stress length reduction).These models included 5 different band insertion models:Model 1 with one band at anterior to the middle of papillary muscle;Model 2 with one band at posterior to the middle of papillary muscle;Model 3 with 2 bands which are the ones from Models 1&2 combined;Model 4 with a band at the base of the papillary muscle;Model 5 with 3 bands which is a combination of Models 3&4.A pre-shrink process was performed on in-vivo begin-filling and end-systole MRI data to obtain diastole and systole zero4oad ventricle geometries.An extra 5%-8%shrinkage was applied to obtain corresponding systole zero-load geometry reflecting myocardium sarcomere shortening.The zero-load band length in systole was 10%,15%and 20%shorter than that in diastole according to their corresponding contraction ratio.The nonlinear Mooney-Rivlin model was used to describe the ventricle material properties with their material parameter values adjusted to match measured data with CMR.The band material properties were in the same scale with healthy right ventricle.The RV/LV/Band model construction and solution procedures were the same as described.Results Model 5 with band contraction ratio of 20%has the ability to improve RV ejection fraction to 41.07%,which represented a 3.61%absolute improvement,or 9.6%relative improvement using pre-PVR ejection fraction as the baseline number.The ejection fractions for Models 1-4 with band contraction ratio of 20%were 39.28%,39.47%,38.87%and 40.34%respectively.Compared to models with band contraction ratio15%and 20%,models with band contraction ratio 10%has the least ability on RV ejection fraction improvement with ejection fraction 38.28%,38.00%,38.81%,38.50%and 39.36%corresponding to Models 1-5.Conclusions This pilot work demonstrated that the band insertion surgery may have great potential to improve post-PVR RV cardiac function for patients with repaired TOF.More band contraction ratio and inserted band number may lead to better post-surgery outcome.Further investigations using in-vitro animal experiments and final patient studies are warranted.

Anisotropic Models of Human Pulmonary Root with Bicuspid Pulmonary Valve in Patients with Tetralogy of Fallot: Pulmonary Root Function Assessment and Mechanical Stress Analysis

Background Tetralogy of Fallot(TOF)is the most common cyanotic heart defect,accounting for 10%of all congenital defects.Pulmonary valve stenosis(PVS)is one common right ventricular outflow tract obstruction problem in patients with TOF.Congenital bicuspid pulmonary valve(BPV)is a condition of valvular stenosis,which morphologic feature is the presence of only two pulmonary leaflets instead of the normal tri-leaflet.Congenitally BPV are uncommon and the occurrence is often associated with TOF.Methods The three-dimensional geometric reconstruction of pulmonary root(PR)were based on well-accepted mathematical analytic models with physiological parameters obtained from a typical sample of the pulmonary root used in clinical surgery.The PR geometry included valvular leaflets,sinuses,interleaflet triangles and annulus.The dynamic computational models of normal PR with tri-leaflet and PR with BPV in patients with TOF were developed to investigate the effect of geometric structure of BPV on valve stress and strain distributions and the geometric orifice area.Mechanical properties of pulmonary valve leaflet were obtained from biaxial testing of human pulmonary valve left leaflet,and characterized by an anisotropic Mooney-Rivlin model.The complete cardiac cycle was simulated to observe valve leaflet dynamic stress and strain behaviors.Results Our results indicated that stress/strain distribution patterns of normal tri-leaflet pulmonary valve(TPV)and the BPV were different on valve leaflets when the valve was fully open,but they were similar when valves were completely closed.When the valve was fully open,the BPV maximum stress value on the leaflets was 218.1 kPa,which was 128.0%higher than of the normal TPV value(95.6 kPa),and BPV maximum strain value on the leaflets was 70.7%higher than of the normal TPV.The location of the maximum stress from TPV and BPV were also different,which were found at the bottom of the valve near the leaflet attachment for TPV and the vicinity of cusp of the fusion of two leaflets for BPV,respectively.During the valve was fully open,the stress distribution in the interleaflet triangles region of the PR was more asymmetric in the BPV model compared with that in the normal TPV model,and the largest change on the PR with the geometrical variations in the two models was 39.6%in maximum stress.This stress asymmetry indicates that BPV may be one of the causes of post-stenotic pulmonary artery dilatation and aneurysm in patients with TOF.The cusp of the BPV model showed significant eccentricity during peak systolic period,and its geometric orifice area value in the completely opened position of valve was reduced 57.5%from that of the normal TPV model.Conclusions Our initial results demonstrated that valve geometrical variations with BPV may be a potential risk factor linked to occurrence of PVS in patients with TOF.Computational models could be used as an effective tool to identifying possible linkage between pulmonary valve malformation disease development and biomechanical factors,better design of artificial valves and new surgical procedures without testing those on patients.Large-scale clinical studies are needed to validate these preliminary findings.

Scalp block for brain abscess drainage in a patient with uncorrected tetralogy of Fallot

We report a case of an 11-year-old boy with diagnosed but uncorrected tetralogy of Fallot presented to us for brain abscess drainage. The child was managed successfully with scalp block with sedation.

Assessment of Right Ventricular Function in Post Operative Patients of Tetralogy of Fallots and Its Predictive Factors

Introduction: Right ventricular (RV) dysfunction can occur early and late in patients after intracardiac repair (ICR) for Tetralogy of Fallots (TOF). This study focuses on early RV dysfunction as there is limited data on it. Aims & Objective: RV function was studied with respect to its incidence, course over 3 months, co-relation with peri operative factors and serum iron levels. Material & Method: All patients of TOF undergoing ICR during July 2007-October 2008, done by single surgeon at a single centre, were prospectively studied. Patients were divided into group A (with RV dysfunction) and group B (without RV dysfunction). All patients underwent pre operative & post operative clinical assessment, biochemical evaluation (serum iron profile & CK MB) and 2D echocardiography (pulse Doppler & tissue Doppler). Echocardiography was done at 24 hours, 4 weeks & 12 weeks of ICR. Patients were also assessed for intra operative parameters including cross clamp time, by pass time, acidosis, RV and PA pressures. Results: 24 patients underwent ICR (transannular patch repair) with mean age of 7.31 ± 4.74 years. RV dysfunction was present in 13 patients (54.2%) but was persistent only in 15.3% (2/13) at 12 weeks. Presence of cyanotic spell (p = 0.006), recurrent chest infection (p = 0.002), raised heamatocrit (p = 0.02), and rise in serum iron level (p = 0.002) were significantly associated with post operative RV dysfunction. It resulted in prolong ICU stay and slower recovery. Pre operative RV dysfunction was associated with difficult weaning from bypass and poor post operative outcome (p < 0.001). Conclusion: RV dysfunction is commonly present even after satisfactory ICR. Its aetiology remains unclear in such setting. In our study, pre operative clinical profile and serum iron fluctuations were important determinants of post operative outcome.

Polytetrafluoroethylene Patch versus Autologous Pericardial Patch for Right Ventricular Outflow Tract Reconstruction in Patients with Tetralogy of Fallot

Objective: For patients of TOF with pulmonary annular hypoplasia, reconstruction of right ventricular outflow tract (RVOT) often requires a trans annular patch (TAP). The present study aims to compare the outcomes of TOF repair using Polytetrafluoroethylene (PTFE) patch versus autologous glutaraldehyde fixed pericardial patch for RVOT reconstruction. Materials and methods: 103 consecutive patients undergoing TOF repair in whom TAP was required were randomized into two groups: Group I (pericardial patch), Group II (PTFE patch). Postoperative outcomes in terms of postoperative heart rhythm, duration of mechanical ventilation, mediastinal and pleural drainage, length of stay in intensive care unit (ICU) and hospital mortality were assessed. A separate team of cardiologists independently evaluated pre- and post-operative gradients across the RVOT, degree of pulmonary insufficiency, right ventricular systolic function. Results: There were no significant differences between the two groups in terms of the incidence of postoperative arrhythmias, duration of mechanical ventilation, length of intensive care unit or hospital stay. The requirement of inotropes was no different in the PTFE patch group as compared with the pericardial patch group (16.84 ± 7.04 vs. 17.90 ± 6.71, median 19 vs. 20, p = 0.825). The re-exploration rate was higher in the PTFE group as compared with the pericardial patch group (6 vs. 1). Postoperative Echocar-diography revealed no differences in the RV systolic function between the two groups before discharge. Conclusion: In patients undergoing TOF repair, using a PTFE patch yields comparable results. However, the efficacy of PTFE will only be established once;mid-term and long-term results are available.

The Variation in Plasma Cortisol Levels in Response to Anesthetic Induction with Etomidate or Ketamine in Children Undergoing Intracardiac Repair of Tetralogy of Fallot on Cardiopulmonary Bypass

Objective: To compare the effect of a single induction dose of etomidate or ketamine on plasma cortisol levels in children with Tetralogy of Fallot (TOF) undergoing intra-cardiac repair on cardiopulmonary bypass (CPB). Design: A prospective randomized trial. Setting: Cardiac center of a tertiary care hospital. Participants: Thirty children with TOF undergoing intra-cardiac repair on CPB. Interventions: After random allocation of the children into two groups, the children either received etomidate 0.2 mg/kg or ketamine 2 mg/kg intravenously for anesthetic induction along with fentanyl 2 mcg/kg and midazolam 100 mcg/kg. Endotracheal intubation was accomplished with rocuronium bromide in the dose of 1 mg/kg. Anesthesia was maintained with sevoflurane in air-oxygen, titrated to response and supplemental vecuronium bromide for muscle relaxation, fentanyl chloride for pain relief. Serum cortisol was measured on three occasions, at preinduction, at the end of surgery and at 24 hours postoperatively. Measurements and Main Results: Baseline plasma cortisol (Normal 5 - 25 mcg/dl) in the etomidate group (19.91 ± 3.51 mcg/dl) decreased significantly at the end of surgery (5.78 ± 2.0 mcg/dl) and rose to significantly higher than baseline values at 24 hours (27.31 ± 8.30 mcg/dl). The baseline cortisol levels in the ketamine group (20.91 ± 3.19 mcg/dl) increased significantly at the end of surgery (44.02 ± 5.49 mcg/dl) and remained significantly higher than baseline at 24hours (45.93 ± 3.05 mcg/dl). Plasma cortisol levels in the etomidate group at end of surgery, and at 24 hours post-operatively, were significantly lower than the ketamine group. Conclusions: This study shows that etomidate is a suitable and safe agent for suppression of the increase in serum cortisol associated with the use of CPB in children with TOF undergoing intra-cardiac repair.