Search

Cardiac amyloidosis is frequently misdiagnosed, denying patients the opportunity for timely and appropriate management of the disease. The purpose of this review and case studies is to raise awareness of the diagnostic “red flags” associated with cardiac amyloidosis and the currently available non-invasive strategies for diagnosis. The review focuses on the identification of one of the two main types of cardiac amyloidosis, transthyretin amyloid cardiomyopathy, and non-invasive tools to distinguish this from light-chain amyloidosis. A diagnostic algorithm centered around the use of non-invasive imaging and laboratory analysis is presented. The algorithm generates four differential diagnoses for patients presenting with signs and symptoms consistent with cardiac amyloidosis. Case examples are presented, representing the four potential outcomes of diagnosis using the algorithm. The review provides a guide on how to recognize the often-overlooked presentations of this disease in clinical practice. Non-invasive imaging techniques and diagnostic tools that do not require the involvement of a specialty center have allowed for the improved diagnosis of cardiac amyloidosis. Timely diagnosis of this life-threatening disease is essential for optimal management and it is imperative that clinicians have a high index of suspicion for patients presenting with “red flag” symptoms.

Organ allocation for transplantation across the United States is administered by the United Network for Organ Sharing (UNOS). UNOS recently approved a major policy change of the system used to allocate hearts for adult transplant candidates. The main objective of this study is to investigate the impact of the new policy on geographic disparity measured by four performance indicators (waiting time before a transplant, transplant rate, pre-transplant mortality rate, and average distance traveled by donated hearts). The current policy and the new policy were evaluated using the thoracic simulation allocation model. The results show that the new policy improves the median waiting time, transplant rate, and pre-transplant mortality rate. The overall predicted improvement in geographic equity is modest except in terms of waiting time. The findings highlight the need for a targeted approach for donor heart allocation to achieve equal access to heart transplantation in the US.

Advanced percutaneous and surgical procedures in structural and congenital heart disease require precise pre-procedural planning and continuous quality control. Although current imaging modalities and post-processing software assists with peri-procedural guidance, their capabilities for spatial conceptualization remain limited in two- and three-dimensional representations. In contrast, 3D printing offers not only improved visualization for procedural planning, but provides substantial information on the accuracy of surgical reconstruction and device implantations. Peri-procedural 3D printing has the potential to set standards of quality assurance and individualized healthcare in cardiovascular medicine and surgery. Nowadays, a variety of clinical applications are available showing how accurate 3D computer reformatting and physical 3D printouts of native anatomy, embedded pathology, and implants are and how they may assist in the development of innovative therapies. Accurate imaging of pathology including target region for intervention, its anatomic features and spatial relation to the surrounding structures is critical for selecting optimal approach and evaluation of procedural results. This review describes clinical applications of 3D printing, outlines current limitations, and highlights future implications for quality control, advanced medical education and training.

The presence of a cardiovascular implantable electronic device has long been a contraindication for the performance of magnetic resonance imaging (MRI). We established a prospective registry to determine the risks associated with MRI at a magnetic field strength of 1.5 tesla for patients who had a pacemaker or implantable cardioverter-defibrillator (ICD) that was "non-MRI-conditional" (i.e., not approved by the Food and Drug Administration for MRI scanning).Patients in the registry were referred for clinically indicated nonthoracic MRI at a field strength of 1.5 tesla. Devices were interrogated before and after MRI with the use of a standardized protocol and were appropriately reprogrammed before the scanning. The primary end points were death, generator or lead failure, induced arrhythmia, loss of capture, or electrical reset during the scanning. The secondary end points were changes in device settings.MRI was performed in 1000 cases in which patients had a pacemaker and in 500 cases in which patients had an ICD. No deaths, lead failures, losses of capture, or ventricular arrhythmias occurred during MRI. One ICD generator could not be interrogated after MRI and required immediate replacement; the device had not been appropriately programmed per protocol before the MRI. We observed six cases of self-terminating atrial fibrillation or flutter and six cases of partial electrical reset. Changes in lead impedance, pacing threshold, battery voltage, and P-wave and R-wave amplitude exceeded prespecified thresholds in a small number of cases. Repeat MRI was not associated with an increase in adverse events.In this study, device or lead failure did not occur in any patient with a non-MRI-conditional pacemaker or ICD who underwent clinically indicated nonthoracic MRI at 1.5 tesla, was appropriately screened, and had the device reprogrammed in accordance with the prespecified protocol. (Funded by St. Jude Medical and others; MagnaSafe ClinicalTrials.gov number, NCT00907361 .).

Purpose In the United States, heart allocation is administered by the United Network for Organ Sharing (UNOS). UNOS collects demographics and clinical data for all transplant candidates, donors, and recipients listed since 1995. While the data is available to the public upon requests; it has been used predominately for research rather than clinical decision making, transplant patient use and policy makers. The aim of this project is to build a web application to visualizes UNOS data and promote easy access to summary statistics for diverse members of the transplant community. Methods This highly interactive web application was developed using the UNOS data between 2006 and 2014 using modern Javascript-based technologies such as Vue.js and Google Maps to show graphs, choropleth and kriging maps. The application is made publicly available on the internet to allow the users to visualize different statistics for different geographic granularity level, (i.e., Transplant center, OPO's donor service area and UNOS region) either by directly selecting locations on the USA map or by selecting an option from a drop-down menu. Several statistics are visualized for different years and for heart-alone or multi-organ transplants. A general map of the US is visible to show the data at the national and OPO levels to give an overall view of the geographic differences across the US states. Drop-down menus are available to select the preferred statistics and indicators by transplant center or UNOS region. Results Several statistics are displayed for different geographic levels and for each year between 2006 and 2014. The set of statistics includes: Probability of receiving a donor heart, % of declined offers because of quality reasons, % of accepted offers of low/medium/high quality, Average cold-ischemic time of the transplanted organs, Average waiting time of a recipient, 1-year, 3-years, 5-years post-transplant mortality rate, 1-year, 3-years, 5-years post-transplant graft failure rate, % of unused organs, % of declined offers because of quality reasons. Conclusion The web application creates maps of several statistics summarizing the available data to provide a useful tool to support decisions for a general audience. The provided interactive maps are a useful tool for improved visual understanding of the heart transplant information for abroad audience, including, patients, OPOs, transplant surgeons and policy makers.

INTRODUCTION In 2008, the Florida Radiological Society (FRS) developed the FRS Legislative Fellowship in Tallahassee with the purpose of introducing radiology residents to both organized medicine and the political process. At the time, the fellowship was the first grassroots, state-level governmental experience within the ACR [1]. It has since been emulated by other state chapters of the ACR, including those of Texas, Michigan, and Washington [2]. The FRS fellowship model is under consideration by other ACR chapters. Moreover, each of these fellowship programs is in part modeled after the ongoing nationallevel Rutherford-Lavanty Fellowship, established in 1993 by the ACR to provide radiology residents direct personal exposure to ACR government relations activities. In this article, we assess the impact of the fellowship on the individual participants and the return for the state chapter.

The pulmonary atresia and intact ventricular septum (PAIVS) spectrum usually includes very hypoplastic right ventricles (RVs) and tricuspid valves (TVs) and often RV-coronary artery connections (RV-CACs). These abnormalities are often thought irreversible and typically only 30% reach a 2-ventricle repair (2VR). Our hypothesis, however, has been PAIVS is a developmental defect and catch-up growth is possible in all. To answer this question, we attempted to obtain up to 10year echo data on RV and TV growth and function in the 24 survivors (of 28 patients) from 1989 to 1999. To maximize the validity of the growth results obtained, we used only paired studies and required biplane echos to accurately estimate RV volumes, TV size, and function. Measurements were indexed to determine the z score (standard deviation of the mean from predicted). All patients had an RV outflow patch and ASD reduction. We have found catch-up growth required complete relief of RV obstruction and a mildly restrictive (3–5mmHg) ASD to encourage TV flow. A central shunt was placed in 38%. RV-CACs (2.7±1.6/pt) were uneventfully ligated off bypass in 9/28 (32%). For the 24 survivors, 19 adequate paired biplane studies were obtained from here and elsewhere and for 12 allowed a 10year follow-up. The RV volume z scores grew from −5.1±2.5 to 0.9±1.9 about 10years later. The TVs, even with increased flow early, grew more slowly than the RVs. Nevertheless, the very small TVs in 10 pts went from z scores of −4.6±0.4 to −0.04±−1.5 within about 5–10years. Valvotomies were done in 3. RV function was high normal (EF=74.5±0.1%) presumably because of pulmonary regurgitation in the 8 pts who had adequate studies. We conclude: (1) Catch-up growth appears reliable in PAIVS pts when RV obstruction is relieved and TV flow is increased (2) RV function was good and resembled well-repaired TOF (3) These results encourage pursuing 2VRs in PAIVS patients.

Objectives To determine the pattern of feeding milestones following primary repair of long-gap esophageal atresia (EA). Method A questionnaire based upon well established feeding milestones was used. Children after long-gap EA repair, n = 40, were compared from after primary repair to healthy children from birth, n = 102. Results The age when surveyed of the EA group and controls was different: 6.2 ± 4.7 (mean ± standard deviation) years, range 1.1–20.9, versus 2.5 ± 2.4 years, range 0.0–12.1, p = 0.00. The esophageal gap length in the EA group was 5.1 ± 1.2 cm and age at repair was 5.5 ± 5.0 months. There was no statistically significant difference between the atresia group and controls for feeding milestones; Self feeding finger foods approached significance. There was, however, greater variability in the timing of milestones in the atresia group compared to controls. Feeding milestones were negatively correlated with age at primary repair: drinking with a covered sippy cup, ρ = − 0.51, p = 0.01 and self feeding finger foods, ρ = − 0.36, p = 0.04 were statistically significant. Drinking from a cup correlated with gestational age, ρ = 0.38, p = 0.04, and negatively correlated to esophageal gap length, ρ = − 0.45, p = 0.01. Conclusions Despite delayed onset of feeding, major milestones after EA repair occurred in similar pattern to normal infants. An early referral for primary repair is beneficial for earlier acquisition of milestones for infants with long-gap EA.

Vascular endothelial cells (ECs) can be injured in a variety of pathologic processes that involve activated complement. We reported previously that porcine ECs incubated with exogenous IL-4 or IL-13 are protected from cytotoxicity by human complement and also from apoptosis by TNF-α. The resistance to complement consists of an intrinsic mechanism that is lost a few days after cytokine removal. In our current study, we investigated whether transfer of the IL-4 gene into porcine ECs in vitro and into porcine vascular tissues in vivo would induce efficient and durable protection from human complement. We found that ECs transduced with adenoIL-4 or adenoIL-13 exhibited continuous production of the cytokine and prolonged protection from complement-mediated killing. IL-4 also protected ECs from activation: ECs incubated with IL-4 did not develop cell retraction and intercellular gaps upon stimulation with sublytic complement. The endothelium and subendothelium of pig iliac arteries that were transduced with the IL-4 gene were effectively protected from complement-dependent immediate injury after perfusion with human blood. However, after similar perfusion, the endothelium was immediately lost from arteries that were transduced with a control adenovirus. The protection was not due to up-regulation of the complement regulators decay accelerating factor, membrane cofactor protein, and CD59, or to reduced complement activation, but required the participation of Akt. Although our studies model protection in pig-to-primate xenotransplantation, our findings of IL-4 induction of Akt-mediated protection may be more broadly applicable to EC injury as manifested in ischemia-reperfusion, allotransplantation, and various vascular diseases.

The donor heart undergoes degradation during hypothermic storage. An assessment of donor heart preservation is typically done with histological or biochemical methods that are not feasible in the clinical setting. We describe a method to study the donor heart using cardiac perfusion MRI that is potentially feasible for clinical use. Standard cardiectomy was performed in the pig model and the hearts were stored in normal saline at 5 degrees C. Imaging was performed by using a rapid gradient-echo sequence (FLASH) with saturation-recovery preparation for T1-weighting in the short axis and horizontal long axis views. Approximately 80 serial images were acquired at a rate of 1/s during administration of 0.006 mmol/ml Gd-DTPA (500 ml, 1 l/min). Signal intensity vs. time curves were generated for each heart and slice imaged and compared to a 0.006 mmol/ml Gd-DTPA reference. HE stained biopsies of the LV, RV, and septum were also obtained. The mean duration of heart storage (N=10) was 8.8 h (range 4.2-19.2 h). Histologically, no differences were seen in HE stained biopsies among hearts at different storage times. However cardiac MRI revealed a decrease in perfusion units in each subsequent heart tested after 4.2 h. (R=0.49). Average peak up-slope was used as a surrogate measure for flow capacity through the microvasculature and peak contrast enhancement was used as a measurement of viable microvasculature. The 4 h heart had 83% peak contrast enhancement of the reference standard, as compared to 44% for the 19.2 h heart. The decrease in peak enhancement is directly related to the duration of storage time. No correlation of peak up-slope of the intensity curve to storage time was found. This new application of cardiac MRI in the donor heart is applicable to: (1) assessing marginal hearts, (2) evaluating donor heart preservation techniques, and (3) correlating pre- to post-transplant viability.

The psychiatric and psychosocial evaluation of the heart transplant candidate can identify particular predictors for postoperative problems. These factors, as identified during the comprehensive evaluation phase, provide an assessment of the candidate in context of the proposed transplantation protocol. Previous issues with compliance, substance abuse, and psychosis are clear indictors of postoperative problems. The prolonged waiting list time provides an additional period to evaluate and provide support to patients having a terminal disease who need a heart transplant, and are undergoing prolonged hospitalization. Following transplantation, the patient is faced with additional challenges of a new self-image, multiple concerns, anxiety, and depression. Ultimately, the success of the heart transplantation remains dependent upon the recipient's ability to cope psychologically and comply with the medication regimen. The limited resource of donor hearts and the high emotional and financial cost of heart transplantation lead to an exhaustive effort to select those patients who will benefit from the improved physical health the heart transplant confers.

The Asporto Heart Preservation Device is a system providing perfusion of cardioplegia to the donor heart using a computer-controlled peristaltic pump in a thermoelectrically cooled and insulated container. In 1998, a user interface was developed at the University of Minnesota consisting of a touch screen and battery-backed microcontroller. Power was supplied by a 120 VAC to 12 VDC converter. An upgrade to the insulated cooler and microcontroller occurred in 2002, which was followed by proof of concept experimental pre-clinical transplants and tests demonstrating the efficacy of the device with isolated donor hearts. During the period between 2002 and 2006, a variety of donor organ containers were developed, modified, and tested to provide an optimal sterile environment and fluid path. Parallel development paths encompass formalized design specifications for final prototypes of the touch screen/microcontroller, organ container, and thermoelectric cooler.

Left ventricular diverticulum is an extremely rare anomaly, especially in the absence of other findings, and as such it has been rarely imaged, rarely seen intraoperatively, and has no standardized management algorithm. We report our suggested imaging and management in the context of previous management philosophies.

This chapter focuses on the ethical principles that have been established and applied to the field of biomedical research and development. At the conclusion of this chapter, we describe a pathway for the development of a new prosthetic heart valve which will be used to illustrate the application of biomedical ethics as it applies today.

The purpose of using animal models in preclinical evaluation of biomaterials is to provide a preliminary assessment of human safety and efficacy relative to the manufacturer claims and comparable technology that can be used as an appropriate control standard. The development of new technologies, including in vitro methods and computer modeling, that has occurred in the last few decades has enhanced the approach to the study of physiology. However, the use of in vivo models still remains a necessity in investigations into certain physiologic phenomena, especially those related to the pathophysiologic mechanisms of disease, as in vitro studies are limited to the assessment of durability of the test material and hemodynamic performance. In this chapter, we will focus on three commonly used animal models for in vivo biomaterials research and testing in cardiac and vascular surgery: pigs; cows; and sheep. The chapter begins with current recommendations for in vivo preclinical evaluation of cardiac and vascular devices and continues with a short discussion on responsible use of animals in the assessment of biomaterials and biomedical devices, followed by specific considerations and examples of existing animal models for each species. Finally, we discuss conventionally-placed devices and percutaneously-placed devices, as well as potential future directions.

We report the case of a 48-year-old male who was found to have an atrial septal defect (ASD) of the secundum type with evidence of moderate right heart load requiring elective device closure. Intraprocedural balloon-sizing showed an average stretched diameter of 16 mm. The decision was made to implant a …

3D volume rendered computed tomography (3D-CT) produces detailed, three-dimensional models that can be rotated and viewed in any orientation to provide a more natural and functional view of the patient's anatomy. This technology is especially beneficial in diagnosing and repairing cardiovascular anomalies. Three cases are presented where 3D-CT was used to diagnose and plan a course of treatment for patients with cardiac anomalies.

Background: The CryoMaze procedure is usually limited to endocardial ablation under cardio-pulmonary bypass. Epicardial ablation is considered inferior as endocardial islets of atrial tissue could theoretically remain viable, protected from cryoinjury by epicardial fat and endocardial circulating warm blood. Novel argon-powered cryoprobes with lower ablation temperatures have recently become available. It is unclear if these instruments can reliably induce transmural atrial fibrosis by epicardial cryoablation on the beating heart. Methods: Ten sheep were divided into two equal groups. CryoMaze ablations were applied using an argon-powered cryoprobe with an ablation temperature of −185°C. In the control group, standardized ablations (n = 50) were applied endocardially under cardiopulmonary bypass. In the experimental group, corresponding ablations (n = 50) were applied epicardially on the beating heart. Postoperatively the animals were monitored for 30 days. At necropsy, the lesions were explanted and analyzed histologically for evidence of transmural fibrosis. Results: Two animals in the control group and one animal in the experimental group died prematurely. Autopsy of the remaining animals showed that all lesions (n = 70) had retained their structural integrity. In the control group, histology demonstrated transmural fibrosis in 94% (28/30) of the endocardially applied lesions. In the experimental group, histology demonstrated transmural fibrosis in 95% (38/40) of the epicardially applied lesions. Statistical analysis revealed no significant difference between the two groups (p = 0.96). Conclusion: Argon-powered epicardial cryoablation on the beating heart is as efficient in inducing transmural fibrosis as the traditional technique of endocardial ablation under cardio-pulmonary bypass. (J Card Surg 2011;26:240-243)

As a consequence of technology improvements and refinement, perfusion of the donor heart has moved from the research laboratory to clinical studies. Multiple investigators are currently leading pre-clinical trials of devices using perfusion preservation, and one device is now in European clinical trials. One major problem with the donor heart is the high metabolism relative to other organs, and depletion of ATP leads rapidly to acidosis and necrosis of the myocardium. Two techniques in development to address the issue are normothermic and hypothermic perfusion. This review examines the current issues regarding donor heart preservation and techniques of pre-clinical evaluation necessary for regulatory approval.

The modern era of cardiac surgery is largely considered to have begun in the animal research laboratories. Today, animal models continue to be used for the study of cardiovascular diseases and are required for the preclinical assessment of pharmaceuticals, mechanical devices, therapeutic procedures, and/or continuation therapies. This chapter was designed to provide readers and potential investigators with important background information necessary for the process of matching an experimental hypothesis to an animal species that will serve as an appropriate model for studying a specific cardiovascular disease or for testing a given medical device. A review of the current animal models used in cardiac research is provided and arranged by disease state. Critical factors to consider when choosing an appropriate animal model including cost, reproducibility, and degree of similarity of the model to human disease are discussed. Thus, this chapter can be utilized as a practical guide for planning of research protocols.

In 3 years, the ABR will be changing the oral board format to a computer-based examination. In anticipation of this, residency training programs must be proactive and optimize the learning environment to maximize residents’ preparation for this examination and their subsequent careers. Undoubtedly, it is vital that training programs provide education to residents to make good clinical judgments rather than using residents for their work product. The optimal residency program provides graduated levels of responsibility such that residents are engaged in active leaning. Unfortunately, radiology residency training programs fall short of providing the optimal “adult” learning as a result of Socratic and didactic lecture style constraints. The problem with the didactic lecture, in which slides are shown one after another with the presenter providing a narrative (typically read from the slide), is that listeners succumb to an insidious mental numbness. In the large lecture halls with the lights low, some residents have actually fallen asleep, as have some attending physicians. Who hasn’t let their mind wander in a long lecture? The attention span of an adult is limited to 20 minutes, and further accumulation of knowledge is not improved by more of the same. Lectures using the Socratic method are lauded for an interactive experience in which an expert guides an individual through a series of questions with the purpose of stimulating critical thinking and illuminating ideas. Here, the reasoning process is considered more important than preconceived facts or beliefs. Unfortunately, the Socratic lecture format is dependent on an expert with a high level of knowledge who corrects erroneous responses before they become “black pearls.” Another problem with the Socratic method is that it can easily degenerate into a pimping session whereby residents recite pertinent facts by rote memory without any thoughtful discourse. An additional issue is the variable application of questions that lead, divert, or even mislead residents. Using these techniques, an examiner can easily make a poor resident look good or a good resident look bad—so not everyone likes the spotlight. The current residency education system using the Socratic method and didactic lecture styles is limited by the inability to incorporate new technologies that maximize decision support. For example, a multiplanar

Background A major problem in procurement of donor hearts is the limited time a donor heart remains viable. After cardiectomy, ischemic hypoxia is the main cause of donor heart degradation. The global myocardial ischemia causes a cascade of oxygen radical formation that cumulates in an elevation in hydrogen ions (decrease in pH), irreversible cellular injury, and potential microvascular changes in perfusion. Objective To determine the changes of prolonged storage times on donor heart microvasculature and the effects of intermittent antegrade perfusion. Materials and Methods Using porcine hearts flushed with a Ribosol-based cardioplegic solution, we examined how storage time affects microvascular myocardial perfusion by using contrast-enhanced magnetic resonance imaging at a mean (SD) of 6.1 (0.6) hours (n=13) or 15.6 (0.6) hours (n=11) after cardiectomy. Finally, to determine if administration of cardioplegic solution affects pH and microvascular perfusion, isolated hearts (group 1, n=9) given a single antegrade dose, were compared with hearts (group 2, n=8) given intermittent antegrade cardioplegia (150 mL, every 30 min, 150 mL/min) by a heart preservation device. Khuri pH probes in left and right ventricular tissue continuously measured hydrogen ion levels, and perfusion intensity on magnetic resonance images was plotted against time. Results Myocardial perfusion measured via magnetic resonance imaging at 6.1 hours was significantly greater than at 15.6 hours (67% vs 30%, P=.00008). In group 1 hearts, the mean (SD) for pH at the end of 6 hours decreased to 6.2 (0.2). In group 2, hearts that received intermittent antegrade cardioplegia, pH at the end of 6 hours was higher at 6.7 (0.3) ( P=.0005). Magnetic resonance imaging showed no significant differences between the 2 groups in contrast enhancement (group 1, 62%; group 2, 40%) or in the wet/dry weight ratio. Conclusion Intermittent perfusion maintains a significantly higher myocardial pH than does a conventional single antegrade dose. This difference may translate into an improved quality of donor hearts procured for transplantation, allowing longer distance procurement, tissue matching, improved outcomes for transplant recipients, and ideally a decrease in transplant-related costs.

Currently, prosthetic heart valve testing is performed on animal models with no underlying cardiovascular pathologies. Unfortunately, unforeseen adverse events may occur when heart valves tested in animals in normal sinus rhythm are implanted in patients suffering from arrhythmias. For example, the Medtronic Parallel valve functioned well in pre-clinical testing, but a high rate of thromboembolic complications appeared when the valve was placed in patients with atrial fibrillation (AF). Given the increasing number of patients afflicted with AF, an animal model of the disorder is needed to more accurately predict a valve's function in the clinical setting. Among methods available for inducing AF, electrophysiological pacing is the most practiced, but the challenges associated with pacing have led to the development of alternative methods of inducing AF These methods include gene transfer and a pharmacologic approach with acetylcholine and catecholamines. Finally, although stem cells have been widely investigated in terms of their therapeutic benefits, the use of their well-reported pro-arrhythmic behavior shows great promise for the development of an AF model in sheep. Such a model would have the potential for detecting adverse outcomes with mechanical heart valves before implantation in the clinical setting.

Black bear bile has been used in traditional Chinese medicine to treat liver and eye related illnesses for centuries. A major constituent of bile is ursodeoxycholic acid (UDCA). Recent analysis of the cellular effects of UDCA and its taurine conjugate tauroursodeoxycholic acid (TUDCA) have demonstrated their antiapoptotic properties through regulation of Bcl-2 family and survival signaling proteins (Bax, Bad, phosphatidylinositol-3-kinase). In this study, we tested the hypothesis that TUDCA administered to rats prior to a myocardial infarction (MI) would exhibit anti-apoptotic effects and improve cardiac function. Prior to ligation of the left anterior descending (LAD) coronary artery, TUDCA (50 mg/ml, 400 mg/kg, IV) or PBS was administered to rats. Animals were sacrificed 24 hours after ligation for terminal transferase-mediated dUTP-digoxigenin nick end-labeling (TUNEL) and caspase-3 activity to assess apoptosis. Additional TUDCA or PBS treated rats underwent pre-operative,1 and 4 week transthoracic ultrasounds to assess heart function by quantification of shortening fraction (SF) and infarct area. TUNEL labeling of the cardiac tissue revealed a significant reduction in apoptotic cells in rats given TUDCA prior to ischemic injury ( p = 0.05). In support of reducing apoptosis, caspase-3 activity in the TUDCA treated animals also decreased ( p = 0.02). By 4 weeks, a significantly smaller infarct area was present in the TUDCA group compared to the PBS group (0.05 vs. 0.13 cm2, p = NS) and there was also an improvement in SF. The results provide evidence for TUDCA as a viable treatment for reducing apoptosis in a model of myocardial infarction. Additional studies will distinguish the functional result of improved cell survival following infarction, suggesting the potential for clinical application of this anti-apoptotic drug in treatment of acute MI.

The in-vivo performance of the Triflo trileaflet mechanical valve was evaluated in an ovine model. The aim of long-term follow up was to gather site-specific performance data demonstrating device safety, as required for regulatory approval of this new valve design, prior to its use in clinical trials.The Triflo trileaflet valve was implanted in 26 sheep using 29-mm mitral (n=8; animal body weight 63.3 +/- 10.3 kg, age 112.0 +/- 30.7 weeks) or 21-mm aortic mechanical valves (n=19; body weight 73.0 +/- 4.36 kg, age 112.6 +/- 23.6 weeks) using standard techniques. Animals were allocated to 150- or 365-day survival cohorts. The 150-day cohort was further subdivided into mitral valve (n=6) and aortic valve (n=11) implants. The 365-day cohort was organized into aortic (n=7) and mitral (n=2) implants. Angiography, echocardiography, and pathology were performed to assess valve performance.Angiographically monitored pressure measurements for the trileaflet mitral valve at 150 and 365 days were within established ranges in terms of mean aortic pressure, systolic and diastolic aortic pressure, and left ventricular end-diastolic pressure. In animals receiving a mitral valve the transvalvular gradient was 3.5 +/- 0.71 mmHg at 365 days, and 0.2 +/- 0.4 mmHg at 150 days. The Triflo mitral valve had only mild (physiologic) regurgitation. Cardiac output was within normal limits in animals receiving the Triflo valve in the aortic position. Laboratory values reflected no ongoing infection or destruction of blood cells as a result of device implantation. No significant abnormality was noted at necropsy in any animal, except for evidence of thromboembolic events in the kidneys (4-20%). Pathological evaluation was reflected by mild to moderate fibrous tissue formation at the inflow orifice (n=15), and minimal growth was observed in the outflow tract of one valve. This was consistent with that seen in sheep implanted with a standard St. Jude Medical bileaflet valve.The study results showed the Triflo valve to perform to safety levels comparable with those of the standard St. Jude Medical bileaflet design, when implanted in the aortic and mitral positions. Additional analysis of historic control data suggested that the trileaflet valve design may offer a reduction in outflow tract obstruction by allowing for a greater effective orifice area index when compared to an equal-sized-orifice bileaflet valve. Notably, the Triflo valve was associated with a statistically significant reduction in myocardial hypertrophy, further reducing the potential for patient-prosthesis mismatch. Overall, the Triflo valve appeared to more closely emulate the hemodynamic properties of the native tissue valve than the traditional bileaflet design. Hence, the trileaflet design may offer the function of a tissue valve while retaining the durability of the mechanical valve.

Effective outcomes in cardiothoracic surgical research using rodents are dependent upon adequate techniques for intubation and mechanical ventilation. Multiple methods are available for intubation of the rat; however, not all techniques are appropriate for survival studies. This article presents a refinement of intubation techniques and a simplified mechanical ventilation setup necessary for intrathoracic surgical procedures using volatile anesthetics. The procedure is defined and complications of the procedure are elucidated that provide a justification for animal numbers needed for initiating new studies. Lewis rats weighing 178-400 g (287 +/- 44) were anesthetized using Enflurane and intubated with a 16-G angiocatheter using transillumination. Mechanical ventilation (85 bpm, 2.5 mL TV, enflurane 1.5-2%) maintained adequate sedation for completion of an intrathoracic procedure. Complications of the intubation and ventilation included mortality from anesthetic overdose, intubation difficulty, pneumothorax, traumatic extubation, and ventilation disconnection. Anesthetic agents and their related effects on the rat heart and reflexes are compared. This article also underscores the importance of refinement, reduction, and replacement in the context of cardiothoracic surgery using rodent models.

Although histological evaluation of the cardiac tissue is the current gold standard for evaluation of rejection, we hypothesized that cardiac perfusion MRI is a safe non-invasive method that correlates tissue blood flow changes with biopsy proven rejection in the cardiac transplant patient.In a retrospective study from 1984-2001, 83 patients underwent 135 MR Gd-DTPA imaging studies. In 8 patients (9%), biopsies graded 2 or higher (by ISHLT criteria) provided evidence of rejection. Patients were age and sex matched to 11 non-rejected controls for imaging analysis. Time-signal intensity curves generated for a mid-ventricle LV short axis slice during rest and adenosine stress allowed determination of myocardial blood flow (MBF, ml/min/gm). ROC curve analysis by SPSS allowed estimation of sensitivity and specificity.At rest, there was no difference in MBF between patients with prior rejection vs. those without (1.18 +/- 0.26 vs. 1.16 +/- 0.29). At stress there was a decrease in MBF for patients with prior rejection episodes (3.27 +/- 0.74) compared to no rejection (3.60 +/- 0.72), P = 0.067). The area under the ROC curve was 0.82, with specificity and sensitivity of 75% and 81%, respectively.This study suggests that perfusion MR imaging can be used in assessing the cardiac transplant patient for rejection related microvascular changes. The high specificity and sensitivity recorded from the ROC curve illustrates the potential utility of this diagnostic test for future studies.

For over 30 years, animal models have remained a central critical component in the pre-clinical safety evaluation of prosthetic heart valves developed for use in humans. Though many advances have been made in valve design, no ideal replacement prosthesis has yet been developed. As a result, valve manufacturers continue to address issues relating to thrombogenicity, structural integrity, fluid dynamics and calcification in their designs. Many animal models have been developed to examine these issues, including dog, pig, calf and sheep, yet no standard model has been accepted. Recently, the International Standard Organization has provided guidelines in document 5840 to address cardiovascular implants. The aim of this report is to provide a summary of the current state of pre-clinical valve evaluation in animals. Changes in ISO 5840 will be addressed that have occurred between 1998 and the present date, and the role of current available animal models. The aim also is to provide rational guidance in the selection of appropriate animal models to match the purpose of valve implantation studies.

Occurrence of immediate post-transplant heart failure in the cardiac transplant recipient is typically attributed to elevated pulmonary vascular resistance, however other etiologies may play a role. At the completion of the transplant, free air, which has collected in the donor heart, is vented via an aortotomy. Free air may rise into the right coronary artery and obstruct reperfusion of the right ventricle. Cardiac perfusion MRI may offer a method of non-invasively determining the presence of air embolus. The objectives in the pilot study were to identify steps in the donor process where free air could enter into the aortic root causing obstruction of perfusion of the coronary arteries. A change in surgical technique could then be used to eliminate a portal of entry and cardiac perfusion MRI could validate the technique. Standard cardiectomy was compared to a variation in technique in two animals. Pulmonary vein ligation was completed in the experimental model before completion of cardiectomy. Both hearts were isolated and imaged using T1-weighted FLASH sequence and gadolinium contrast via the aortic root. Cardiac perfusion MRI imaging of the heart with the unligated pulmonary vein revealed evidence of air embolus and no perfusion of the right coronary artery compared to the ligated heart. Anatomically, the right coronary artery is anterior in the mediastinum compared to the left coronary artery. Air emboli preferentially rise into the right coronary and can obstruct flow into the right heart. Cardiac perfusion MRI offers an effective method to evaluate the isolated pre-transplant heart for perfusion defects.

PART 1 In the past 12 months, the radiology department at the University of Mississippi has developed a new interdisciplinary cardiac imaging program with an operational workflow bridging multiple technological, infrastructural, and budgetary constraints. Before the implementation of this new workflow, the department did not protocol imaging studies or individualize examinations for patients’ clinical indications. Because a single “comprehensive” protocol was used for all cardiac MRI examinations, image acquisition lasted about 2 hours, and the technologist called the radiologist with any questions. The purpose of this report is to describe how disparate operational elements can be combined to form a functional cardiac MRI service. Additionally, this project serves as an example of a practice quality improvement (PQI) project that residents can participate in or lead during training.

In cardiac transplantation, the transport time between harvest and recipient is limited by the viability of the donor heart. The problem of viability is a consistent limitation in cardiac transplantation. Since the 1960s, techniques, including hypothermia, perfusion, oxygenation, and hyperbaria, have been used to prolong the preservation of the transplantable heart. Continuing development of cardioplegic solutions has minimized edema and oxygen radical formation, which have resulted in extension of the donor heart viability. New research into the events leading to necrosis, oncosis, and apoptosis may allow further advancement of protective cardioplegic solutions in combination with technology of transporting the heart. With a prolonged preservation time there is potential to increase the donor pool and ultimately improve post-operative outcomes.

Sodium polystyrene sulfonate (Kayexalate) commonly is used in treating hyperkalemia. As a cation exchange resin, it also can be used to reduce the potassium content of enteral nutrition formulas. This study evaluates the use of Kayexalate to reduce potassium in one high-protein enteral formula and describes the quantitative analysis of the product.Sodium polystyrene sulfonate and enteral formula were mixed into a slurry and allowed to settle, and then the supernatant was decanted off and tested as samples. Three sample concentrations were analyzed: a control not subjected to potassium reduction, 0.5 g of Kayexalate per mEq K+ sample, and a 1 g/mEq K+ sample. Of these samples, moisture, lipid, protein, carbohydrate, ash, and mineral content were obtained.Compared with the control, the percentage decrease of potassium ranged from 25% to 36%, depending on the concentration of Kayexalate. A significant increase of 324% in sodium concentration was found in the 1.0 g/mEq K+ sample. Although there was no change in magnesium content, a slight increase in phosphorus, iron, and zinc was evident.The treatment of an enteral formula with sodium polystyrene sulfonate significantly increases its sodium content, with a modest decrease in potassium content. Clinicians using this method in clinical practice should be aware of the increase in sodium content.

he Florida Radiological Society FRS) developed and funded a Legisative Fellowship in Tallahassee with he purpose to introduce organized edicine and the political process to adiology residents. Two residents, ne each from the University of outh Florida and the University of lorida, participated in the fellowhip during March 2008, while the egislature was in session. To our nowledge, the fellowship was the rst of its kind: a state-level legislative ellowship experience sponsored by a hapter of the ACR. The FRS lobbyist, Alison Dudey organized the fellowship schedle. The 3-day Tallahassee experince included meetings with state