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OBJECTIVE: To use finite element modelling to look at the impact of lumen shape and vessel geometry on stress distribution in a vessel. METHODS: A finite element model of an atherosclerotic plaque in a coronary artery was created and a non-linear analysis with Ogden strain energy function was done. The three most common shapes seen in an artery with an eccentric plaque--namely an elliptical lumen inside a circular vessel (A), a circular lumen inside an elliptical vessel, typical of a vessel with positive remodelling (B), and a circular lumen inside a circular vessel (C)--were modelled with and without lipid. Stress was analysed in the region of the fibrous cap separating the lumen from the plaque and the region of maximum stress along the circumference of the lumen was noted. RESULTS: In a normal circular shaped coronary artery, the haemodynamic stresses were uniformly distributed all around the circle. However, if the circle was changed to an ellipse, the stresses were redistributed along the major axis and dropped substantially along the minor axis. The stresses in a positively remodelled vessel (B) were significantly greater than in A and C, by almost 100%. Moreover, the haemodynamic stresses increased significantly towards the major axis or the shoulder in A and B, due to lumen shape and vessel geometry alone, even in the absence of lipid in the model. The stresses also had a direct relation with the thickness of the lipid pool and an inverse relation with cap thickness and lumen stenosis. CONCLUSIONS: The increased vulnerability of the shoulder region of a plaque and a remodelled coronary artery are due, apart from other factors, to increased biomechanical stresses as a result of lumen shape and vessel geometry. [ABSTRACT FROM AUTHOR]

Competing Interests: Conflicts of interest/Competing interestsNil.

Background & Aim: The deleterious consequences of chronically elevated venous pressure in patients with profound right ventricular or biventricular dysfunction are well known, including renal and hepatic dysfunction, and volume overload. The only option for these patients, if they fail optimal medical treatment, is a heart transplant, as they are not candidates for left ventricular assist device therapy. Mean perfusion pressure (MPP) is important in the outcomes of critically ill patients with high venous pressure. The question arises whether MPP is important for the outcomes of heart transplants in patients with elevated pre-transplant venous pressure. Medical management of heart failure patients with reduced ejection fraction involves lowering the systemic afterload with vasodilators while awaiting a transplant. We hypothesised that when venous pressure is elevated prior to transplant, a substantial reduction in systemic arterial elastance (E a ) through vasodilation may significantly decrease MPP, resulting in compromised end-organ function and consequent unfavourable outcomes after heart transplantation. This study aims to investigate whether a low MPP serves as a risk factor for adverse outcomes in heart transplant recipients with high venous pressure., Method: A retrospective analysis was conducted on 250 heart transplant recipients undergoing isolated heart transplantation at a single institution from October 2012 to March 2020. Right atrial pressure (RAP) of more than 15 mmHg was considered high. Additionally, E a calculated as the ratio of end-systolic pressure to stroke volume, and MPP calculated as the difference between mean arterial pressure and RAP were considered in our analysis. The outcomes of transplantation were measured in terms of 90-day mortality and survival up to 7 years., Results: High RAP was a significant risk factor for short-term and medium-term survival if E a was low (<2.7 mmHg/mL, the median value). This group had 39.39% in-hospital mortality compared to 14.49% for RAP<15 mmHg (p∼0.005). When E a was high, this difference in survival was not evident: 8% for RAP<15 mmHg vs 4.8% for RAP>15 mmHg (p∼0.550). This effect was mediated through a lower MPP, and the mortality due to lower MPP increased strikingly with higher body surface area (BSA). A negative correlation was observed between MPP indexed to BSA (MPPI) and the Model for End-Stage Liver Disease score (r∼-0.3580, p<0.0001) as well as creatinine (r∼-0.3551, p<0.0001). MPPI less than 40 mmHg/m 2 was associated with poorer short-term (23.2% for MPPI<40 mmHg/m 2 vs 7.1% for MPPI>40 mmHg/m 2 , p∼0.001) and medium-term survival. The impact of high RAP and low E a on survival was evident even on medium-term follow-up; only 30% survival at 7 years follow-up for high RAP and low E a vs 75% for RAP<15 mmHg (p∼0.0033)., Conclusion: The acceptable blood pressure during vasodilator therapy in patients with high RAP needs to be higher, especially in those with higher BSA. MPPI less than 40 mmHg/m 2 is a risk factor for survival, in the short and medium-term, after heart transplantation., (Copyright © 2024 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Organ donation following circulatory determination of death (DCDD) has contributed significantly to the donor pool in several countries. In India, majority of deceased donations happen following brain death (BD). While existing legislation allows for DCDD, there have been only few reports of kidney transplantation following DCDD from India. This document, prepared by a multidisciplinary group of experts, reviews international best practices in DCDD and outlines the path for DCDD in India. Ethical, medical, legal, economic, procedural, and logistic challenges unique to India have been addressed. The practice of withdrawal of life-sustaining treatment (WLST) in India, laid down by the Supreme Court of India, is time-consuming, possible only in patients in a permanent vegetative state, and too cumbersome for day-to-day practice. In patients where continued medical care is futile, the procedure for WLST is described. In controlled DCDD (category-III), decision for WLST is independent of and delinked from the subsequent possibility of organ donation. Families that are inclined toward organ donation are explained the procedure including the timing and location of WLST, consent for antemortem measures, no-touch period, and the possibility of stand-down and return to the intensive care unit (ICU) without donation. In donation following neurologic determination of death (DNDD), if cardiac arrest occurs during the process of BD declaration, the protocol for DCDD category-IV has been described in detail. In DCDD category-V, organ donation may be possible following unsuccessful cardiopulmonary resuscitation of cardiac arrest in the ICU. An outline of organ-specific requisites for kidney, liver, heart, and lung transplantation following DCDD and techniques, such as normothermic regional perfusion (nRP) and ex vivo machine perfusion, has been provided. The outcomes of transplantation following DCDD are comparable to those following DBDD or living donor transplantation. Documents and checklists necessary for successful execution of DCDD in India are described., How to Cite This Article: Seth AK, Mohanka R, Navin S, Gokhale AGK, Sharma A, Kumar A, et al . Organ Donation after Circulatory Determination of Death in India: A Joint Position Paper. Indian J Crit Care Med 2022;26(4):421-438., Competing Interests: Source of support: Nil Conflict of interest: None, (Copyright © 2022; Jaypee Brothers Medical Publishers (P) Ltd.)

Background: There is a growing population of palliated and unpalliated single ventricle physiology patients for whom heart transplantation is the only treatment option available. There is a paucity of reports of heart transplantation in this challenging and growing subset of patients from our part of the world. The purpose of the article is to briefly review our experience in the subgroup and compare it with the available literature., Methods: This was a single-institution retrospective observational study of 16 patients with single ventricle physiology who were transplanted between 2016 and 2019 and their outcomes. The study groups were divided into those with ventricular dysfunction (group 1), who fare substantially better than those with normal ventricular function (group 2) whose short-term outcomes were poorer. Worsening cyanosis, poor candidature for completion Fontan procedure due to severe atrioventricular valve regurgitation or pulmonary artery anatomy, protein-losing enteropathy, plastic bronchitis, and worsening systemic venous congestion are indications in those with normal ventricular function., Results: Patients with ventricular dysfunction as the main indication had excellent early survival with no early mortality compared to 40% mortality in patients with normal ventricular function. Patients who survived to leave the hospital had however similar long-term outcomes. Two patients with protein-losing enteropathy resolved completely by one month. Normal ventricular function, pulmonary artery stenting, early Fontan failure (6 months), ascites, and need for desensitization were risk factors for early mortality. After the early acute phase of increased risk, the mortality risk plateaued off., Conclusion: Transplantation in patients with single ventricle and ventricular dysfunction can be offered with a good early and late outcome. There is a need to have multi-institutional and multi-disciplinary collaboration along with work in basic sciences to better understand the effects of failed Fontan physiology with normal ventricular function., Competing Interests: Conflict of interestThe authors declare no competing interests., (© Indian Association of Cardiovascular-Thoracic Surgeons 2021.)

Background: Lung transplantation is a life-saving treatment for patients with end-stage lung disease; however, it is infrequently considered for patients with acute respiratory distress syndrome (ARDS) attributable to infectious causes. We aimed to describe the course of disease and early post-transplantation outcomes in critically ill patients with COVID-19 who failed to show lung recovery despite optimal medical management and were deemed to be at imminent risk of dying due to pulmonary complications., Methods: We established a multi-institutional case series that included the first consecutive transplants for severe COVID-19-associated ARDS known to us in the USA, Italy, Austria, and India. De-identified data from participating centres-including information relating to patient demographics and pre-COVID-19 characteristics, pretransplantation disease course, perioperative challenges, pathology of explanted lungs, and post-transplantation outcomes-were collected by Northwestern University (Chicago, IL, USA) and analysed., Findings: Between May 1 and Sept 30, 2020, 12 patients with COVID-19-associated ARDS underwent bilateral lung transplantation at six high-volume transplant centres in the USA (eight recipients at three centres), Italy (two recipients at one centre), Austria (one recipient), and India (one recipient). The median age of recipients was 48 years (IQR 41-51); three of the 12 patients were female. Chest imaging before transplantation showed severe lung damage that did not improve despite prolonged mechanical ventilation and extracorporeal membrane oxygenation. The lung transplant procedure was technically challenging, with severe pleural adhesions, hilar lymphadenopathy, and increased intraoperative transfusion requirements. Pathology of the explanted lungs showed extensive, ongoing acute lung injury with features of lung fibrosis. There was no recurrence of SARS-CoV-2 in the allografts. All patients with COVID-19 could be weaned off extracorporeal support and showed short-term survival similar to that of transplant recipients without COVID-19., Interpretation: The findings from our report show that lung transplantation is the only option for survival in some patients with severe, unresolving COVID-19-associated ARDS, and that the procedure can be done successfully, with good early post-transplantation outcomes, in carefully selected patients., Funding: National Institutes of Health. VIDEO ABSTRACT., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Aims and Objectives: There is a paucity of data regarding the outcomes of Heart transplantation in children from the Indian subcontinent. The data of patients under the age of 18 undergoing an isolated heart transplantation was analyzed for patient clinical profiles and risk factors for early and medium-term mortality. Hospital mortality was defined as death within 90 days of transplantation and medium-term survival as follow up of up to 6 years., Materials and Methods: A total of 97 patients operated between March 2014 and October 2019 were included in this study. Data was collected about their INTERMACS status, pulmonary vascular resistance, donor heart ischemic times, donor age, donor to recipient weight ratio and creatinine levels., Results: The age range was from 1 to 18 with a mean of 10.6 ± 4.6 years. 67 % patients were in INTERMACS category 3 or less.12 children were on mechanical circulatory support at the time of transplant. The 90 day survival was 89 %. The risk factors for hospital mortality was lower INTERMACS category (odd's ratio 0.2143, P = 0.026), elevated creatinine (odd's ratio 5.42, P = 0.076) and elevated right atrial pressure (odd's ratio 1.19, P = 0.015). Ischemic time, pulmonary vascular resistance (PVR) and PVR index (PVRI) had no effect on 90 day survival. Kaplan Meier estimates for 5 year survival was 73 %. The medium term survival was affected by INTERMACS category (Hazard ratio 0.7, P = .078), donor age > 25 (Hazard ratio 1.6, P = 0.26) and raised serum creatinine values.(Hazard ratio 2.7, P = 0.012). All the survivors are in good functional class., Conclusions: Excellent outcomes are possible after heart transplantation in a pediatric population even in a resource constrained environment of a developing economy. More efforts are needed to promote pediatric organ donation and patients need to be referred in better INTERMACS category for optimal outcomes., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Annals of Pediatric Cardiology.)

Objective: End stage heart failure is a lethal disease with a dismal 5 year survival. Heart transplantation has proven to be a highly effective modality of treatment in appropriately selected group of such patients. This is a retrospective analysis of medium term outcomes of heart transplantation in the setting of a private health facility in India. The objective of this study was two fold., Methods: The outcome of 257 heart transplants done at a single centre from October 2012 to October 2019 was analyzed. Patients with combined Heart and lung transplants and those whose complete medical records were unavailable were excluded from the study. Survival was tracked at 60 days, 90 days, one year and beyond for a maximum of 7 years. Preoperative patient risk profiles were characterized on the basis of INTERMACS category., Results: There were 176 male and 81 female patients. The age range was from 8 months to 78 years with a mean of 32.9 years. Survival at 2 months was 87%, at 90 days was 83%, at one year was 81%, 2 years was 75%, at 3 years was 72% and at 5 years and beyond was 62% for the whole series. Strong predictors of 90 day mortality included INTERMACS category (odd's ratio 0.289, p = 0.000) and creatinine more than 1.5 mg/dl (odd's ratio 2.48, p = 0.056). Recipient pulmonary vascular resistance and donor organ ischemic times were not found to be statistically significant factors affecting outcome. Medium term survival was influenced by INTERMACS category (Hazard ratio > 3 for INTERMACS category 1 compared to INTERMACS 4 or 5, p < 0.0001) and creatinine > 1.5 mg/dl (Hazard ratio 2.15, p = 0.003). This effect of creatinine was related to the age of the recipient. Hazard ratio 1.4, p = 0.524 if age <30 and Hazard ratio 4.78, p = 0.006, if age was >50., Conclusion: Satisfactory medium term outcome is possible after heart transplantation even in resource constrained environment of a developing country., Competing Interests: Conflicts of interest All authors have nothing to declare., (Copyright © 2020 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.)

Multimodality therapies have improved the survival after tumors like Ewing's sarcoma and breast cancer. However, cardiotoxicity following chemotherapy remains an important concern. We report a case series of four patients who presented to our heart team with severe dilated cardiomyopathy along with biventricular involvement. Two of the patients were females and had breast cancer for which they were treated with trastuzumab and had developed chemotherapy induced cardiomyopathy (CCMP). The other two patients were males who had Ewing's sarcoma who developed CCMP following treatment with doxorubicin., Competing Interests: Conflict of interestThe authors declare that they have no conflicts of interest., (© Indian Association of Cardiovascular-Thoracic Surgeons 2020.)

One of the most devastating complications of continuous flow left ventricular devices (CFLVADS) is stroke, with a higher incidence in HeartWare Ventricular Assist Device (HVAD) as compared with HEARTMATE II. The reason for the observed difference in stroke rates is unclear. Because outflow graft diameters are different, we hypothesized that this could contribute to the difference in stroke rates. A computational fluid-structure interaction model was created from the computed tomography (CT) scan of a patient. Pressures were used as the boundary condition and the flow through the cerebral vessels was derived as outputs. Flow into the innominate artery was very sensitive to the anastomosis angle for a 10 mm as compared with a 14 mm graft, with the net innominate flow severely compromised with a 10 mm graft at 45° angle. Aortic insufficiency seems to affect cerebral blood flow nonlinearly with an 80% decrease at certain angles of outflow graft anastomosis. Arterial return in to the arch through a narrow graft has important jet effects and results in significant flow perturbations in the aortic arch and cerebral vessels and stasis. A 10 mm graft is more sensitive to angle of insertion than a 14 mm graft. Under some conditions, serious hypoperfusion of the innominate artery is possible. Aortic incompetence results in significant decrease of cerebral blood flow. No stasis was found in the pulsatile flow compared with LVAD flow.

Comparative study among aortic valves requires the use of an unbiased and relevant boundary condition. Pressure and flow boundary conditions used in literature are not sufficient for an unbiased analysis. We need a different boundary condition to analyze the valves in an unbiased, relevant environment. The proposed boundary condition is a combination of the pressure and flow boundary condition methods, which is chosen considering the demerits of the pressure and flow boundary conditions. In order to study the valve in its natural environment and to give a comparative analysis between different boundary conditions, a fluid-structure interaction analysis is made using the pressure and the proposed boundary conditions for a normal aortic valve. Commercial software LS-DYNA is used in all our analysis. The proposed boundary condition ensures a full opening of the valve with reduced valve regurgitation. It is found that for a very marginal raise in the ventricular pressure caused by pumping a fixed stroke volume, the cardiac output is considerably raised. The mechanics of the valve is similar between these two boundary conditions, however we observe that the importance of the root to raise the cardiac output may be overstated, considering the importance of the fully open nodule of arantius. Our proposed boundary condition delivers all the insights offered by the pressure and flow boundary conditions, along with providing an unbiased framework for the analysis of different valves and hence, more suitable for comparative analysis., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Flow cytometry is a ubiquitous, multiparametric method for characterizing cellular populations. However, this method can grow increasingly complex with the number of proteins that need to be screened simultaneously: spectral emission overlap of fluorophores and the subsequent need for compensation, lengthy sample preparation, and multiple control tests that need to be performed separately must all be considered. These factors lead to increased costs, and consequently, flow cytometry is performed in core facilities with a dedicated technician operating the instrument. Here, we describe a low-cost, label-free microfluidic method that can determine the phenotypic profiles of single cells. Our method employs Node-Pore Sensing to measure the transit times of cells as they interact with a series of different antibodies, each corresponding to a specific cell-surface antigen, that have been functionalized in a single microfluidic channel. We demonstrate the capabilities of our method not only by screening two acute promyelocytic leukemia human cells lines (NB4 and AP-1060) for myeloid antigens, CD13, CD14, CD15, and CD33, simultaneously, but also by distinguishing a mixture of cells of similar size—AP-1060 and NALM-1—based on surface markers CD13 and HLA-DR. Furthermore, we show that our method can screen complex subpopulations in clinical samples: we successfully identified the blast population in primary human bone marrow samples from patients with acute myeloid leukemia and screened these cells for CD13, CD34, and HLA-DR. We show that our label-free method is an affordable, highly sensitive, and user-friendly technology that has the potential to transform cellular screening at the benchside.

An adult with unoperated tetralogy of Fallot diagnosed simultaneously with pheochromocytoma is extremely rare. This poses obvious diagnostic and therapeutic challenges. A 29-year-old woman with these conditions was successfully operated on for both diseases in the same hospitalization. There is some interesting speculation regarding the association of pheochromocytoma with uncorrected cyanotic congenital heart disease.

Objective: To compare the opening mechanics of porcine valve substitutes with those of a normal human aortic valve., Background: All commercially available porcine valves are pretreated with glutaraldehyde. This study was undertaken to evaluate the consequences of such treatment on valve mechanics., Methods: The opening mechanics of the aortic valve, especially the time taken to open fully from a closed position, and the duration for which the valve is maximally open, were compared in a normal aortic valve, a stent-mounted porcine valve, and a stentless porcine valve, using a finite element model., Results: Despite a 4-fold higher gradient, stent-mounted porcine valves were slower in attaining the fully open position, and the time for which the valve was fully open was almost 25% less than a normal valve. In stentless valves, the compliant root made the initial opening mechanics similar to those of a normal valve. Once this effect was over, the effect of porcine leaflet properties took over, and there was a corresponding delay in the valve opening., Conclusions: Fixing the root with a stent and stiffening the leaflets with glutaraldehyde result in delayed valve opening and decrease the duration for which the valve is fully open, thus contributing to inferior hemodynamics.

Resistive-pulse sensing (RPS), which is based on measuring the current pulse produced when a single particle transits a pore or channel, is an extremely versatile technique used to determine the size and concentration of cells and viruses and to detect single molecules. A major challenge to RPS is dynamic range: smaller particles in a heterogeneous sample can go undetected because of low signal-to-noise ratios (SNRs) and the fact that the pore size must be commensurate with that of the largest particles. Here, we describe a fundamentally different pore that provides an unprecedented dynamic detection range, from tens of nanometers to several microns in size, without the need for pre-sorting or filtration. Because of its unique geometry--nodes inserted along the channel--our pore produces distinct electronic signatures that overcome low SNRs. We demonstrate the power of our device by directly detecting and enumerating human immunodeficiency virus (HIV) in human plasma.

Traditional cell-screening techniques such as FACS and MACS are better suited for large numbers of cells isolated from bulk tissue and cannot easily screen stem or progenitor cells from minute populations found in their physiological niches. Furthermore, these techniques rely upon irreversible antibody binding, potentially altering cell properties, including gene expression and regenerative capacity. To address these challenges, we have developed a novel, label-free stem-cell analysis and sorting platform capable of quantifying cell-surface marker expression of single functional organ stem cells directly isolated from their micro-anatomical niche. Using our unique platform, we have discovered a remarkable heterogeneity in both the regenerative capacity and expression of CXCR4, β1-integrin, Sca-1, M-cadherin, Syndecan-4, and Notch-1 in freshly isolated muscle stem (satellite) cells residing on different, single myofibers and have identified a small population of Sca-1(+)/Myf5(+) myogenic satellite cells. Our results demonstrate the utility of our single-cell platform for uncovering and functionally characterizing stem-cell heterogeneity in the organ microniche.

An alternative technique for the repair of supracardiac total anomalous pulmonary venous return (TAPVR) is described. The pulmonary venous confluence (CPV) is identified below the right pulmonary artery between the aorta and superior vena cava. The atrial incisions are similar to a septosuperior approach of the mitral valve, modifying the incision on the roof of the left atrium to be parallel to the incision in the CPV. The common pulmonary vein is anastomosed to the roof of the left atrium. This approach offers optimal exposure for the repair without distorting the cardiac structures.

Pseudoaneurysm of the popliteal artery is much less common than true aneurysm in this location. We report 3 cases of popliteal artery pseudoaneurysms, each of differing etiopathology, one presenting 3 months after trauma, one following aortic valve replacement for aortic regurgitation with suspected endocarditis, with no organism detected, and the 3rd of infective etiology. The clinical presentation and surgical management are discussed with a review of the literature.

Severe coronary artery disease with coarctation of the aorta is an unusual and challenging clinical problem. We encountered three adults with severe coronary artery disease and tight coarctation of the aorta. Since angina was the dominant symptom in all, off-pump coronary artery bypass grafting (OPCABG) was done as a first stage. All survived the operation. After a gap of 3 weeks, coarctation repair has been done in 1 patient. We believe that OPCABG offers some unique advantages in this difficult situation.

Infants with atrial septal defects are seldom symptomatic and usually require elective surgery between 2 and 4 years of age. However a small minority is symptomatic and management at this age has been controversial. This study evaluated surgical closure of atrial septal defect below 2 years of age. Eighteen infants with a mean age of 13.4 +/- 5.7 months were operated on for secundum atrial septal defect from 1994 to 2001. Fourteen patients were symptomatic with failure to thrive in 7 and recurrent respiratory infections in 7, one had increasing cardiomegaly, and 3 were operated on early for social reasons. The defect was isolated in 11 patients (61%) and the other 7 (39%) had minor associated lesions requiring additional procedures such as ductal ligation, direct closure of a tiny ventricular septal defect, and inspection of the mitral valve. There were no early or late deaths. The postoperative course was complicated by pulmonary problems in 4 cases. Of the 16 patients available for follow-up, 14 were asymptomatic and 2 were symptomatically improved. Most showed a dramatic improvement in growth and development. These gratifying results indicate that consideration should be given to early surgical closure of atrial septal defect in symptomatic infants.

Aims: To analyze peroperative biopsies of RV myocardium in Tetralogy of Fallot by light microscopy, morphometry and electron microscopy in order to determine the degree of hypertrophy and degenerative changes and to correlate these changes with clinical and haemodynamic parameters., Materials and Methods: Right ventricular myocardium obtained peroperatively during surgical correction of Tetralogy of Fallot along with age-matched control samples were processed for routine light and electron microscopy using standard processing techniques. Mean cell diameter was analyzed using manual morphometric methods and ultrastructural study was carried out using a Philips transmission electron microscope., Results: The most consistent features of hypertrophy were the mitochondrial changes and increased nuclear convolutions. Majority of the patients had hypertrophy with mild to moderate degenerative changes. Severe degeneration was associated with irreversibility and was related to the severity and chronicity of the disease. There was a significant correlation of the morphological changes with clinical and haemodynamic parameters., Conclusions: Peroperative histomorphometric and ultrastructural evaluation of the RV myocardium in Tetralogy of Fallot reflects the effect of haemodynamic stresses on the right ventricular muscle and correlates with clinical cardiac dysfunction. It may be a useful adjunct in determining the time for surgical intervention and in predicting clinical outcome.

Background: This study aims to find the fundamental differences in the mechanism of opening and closing of a normal aortic valve and a valve with a stiff root, using a dynamic finite element model., Methods: A dynamic, finite element model with time varying pressure was used in this study. Shell elements with linear elastic properties for the leaflet and root were used. Two different cases were analyzed: (1) normal leaflets inside a compliant root, and (2) normal leaflets inside a stiff root., Results: A compliant aortic root contributes substantially to the smooth and symmetrical leaflet opening with minimal gradients. In contrast, the leaflet opening inside a stiff root is delayed, asymmetric, and wrinkled. However, this wrinkling is not associated with increased leaflet stresses. In compliant roots, the effective valve orifice area can substantially increase because of increased root pressure and transvalvular gradients. In stiff roots this effect is strikingly absent., Conclusions: A compliant aortic root contributes substantially to smooth and symmetrical leaflet opening with minimal gradients. The compliance also contributes much to the ability of the normal aortic valve to increase its effective valve orifice in response to physiologic demands of exercise. This effect is strikingly absent in stiff roots.

Background: The major aim of this study was to examine the leaflet/aortic root interaction during the cardiac cycle, including the stresses developed during the interaction., Methods: Dynamic finite element analysis was used along with a geometrically accurate model of the aortic valve and the sinuses. Shell elements along with proper contact conditions were also used in the model. Pressure patterns during the cardiac cycle were given as an input, and a linear elastic model was assumed for the material., Results: We found that aortic root dilation starts before the opening of the leaflet and is substantial by the time leaflet opens. Dilation of the root alone helps in opening the leaflet to about 20%. The equivalent stress pattern shows an instantaneous increase in stress at the coaptation surface during closure. Stresses increase as the point of attachment is approached from the free surface., Conclusions: The complex interplay of the geometry of the valve system can be effectively analyzed using a sophisticated dynamic finite element model. Results not previously brought out by the earlier static analysis shed new light on the root/valve interaction.

A 3 1/2-year-old female child presented with massive hemoptysis 5 months after a modified Blalock-Taussig (BT) shunt for double-outlet right ventricle with pulmonary stenosis. Computerized tomographic scan and angiography showed a false aneurysm of the subclavian artery at the insertion of the shunt. Successful surgical management is discussed.

Children with Down's syndrome and congenital heart defects have multiple problems. The role of cardiac surgery in the management of these patients was investigated by reviewing the clinical data, hospital course and follow-up of 21 patients (9 males and 12 females, age range 1 month to 14 years) with Down's syndrome and congenital heart defects operated in our institute. Twelve (57%) of these were infants and nine (43%), older children. Five were in congestive cardiac failure, four were hypothyroid. The heart lesions ranked in incidence as follows: atrioventricular septal defect 7 (33.3%), tetralogy of Fallot 3 (14.3%), tetralogy of Fallot & atrioventricular septal defect both 2 (9.5%), double outlet right ventricle with pulmonary stenosis 1 (4.8%), patent ductus arteriosus 2 (9.5%), patent ductus arteriosus plus coarctation 1 (4.8%), ventricular septal defect 2 (9.5%), atrial septal defect plus ventricular septal defect 1 (4.8%), atrial septal defect plus patent ductus arteriosus plus right pulmonary artery stenosis 1 (4.8%) and transposition of great arteries with multiple ventricular septal defect 1 (4.8%). Four (19%) patients had palliative procedures while the rest (81%) underwent primary repair. All survived the operation. The post-operative period was complicated in 6 (28.5%), with respiratory infections in 3, pulmonary hypertensive crisis in 2 and complete heart block in 1. The early mortality was 0, while there were 2 (9.5%) late deaths. The number of hospitalisations was markedly reduced according to the parents. Follow-up showed near normal pulmonary artery pressure in 50 percent children with large shunts and a good developmental spurt was seen in 60 percent. From a purely surgical viewpoint, the prognosis for children with Down's syndrome and congenital heart disease is good.

Ball valve thrombus is a very rare cardiac pathological entity; most case reports are postmortem. It is always associated with a very tight rheumatic mitral stenosis. The antemortem diagnosis of ball valve thrombus has become easy with the advent of echocardiography and even easier with biplane or multiplane transesophageal echocardiography, including the three-dimensional acquisition of images. We present the case of a patient with a ball valve thrombus diagnosed during routine echocardiographic examination as a prelude to surgery.

A 2-year-old male child presented with fever, complete heart block, and congestive cardiac failure. Echocardiography showed a dumbbell-shaped mass in the right ventricle and right atrium. He was operated on with a provisional diagnosis of rhabdomyoma. Histopathology and immunohistochemistry of the resected tumor revealed a malignant germ cell tumor with predominant yolk sac differentiation.

A 43 year old patient who underwent mitral valve replacement had pulmonary artery catheter inserted before induction of anaesthesia. The catheter could no be removed postoperatively by routine manoeuvres in the intensive care unit. Fluoroscopy in the cardiac catheterization revealed a straight course of the catheter indicating the probability of its inclusion in the left atrial suture line. The pulmonary artery catheter was successfully removed percutaneously in the cardiac catheterization laborartory. The procedure is described.