The use of simulation in liver transplantation anesthesiology fellowship training: A survey of fellowship program directors in the United States.

INTRODUCTION: Liver transplantation surgeries are challenging cases for anesthesiologists. While intra-operative teaching is paramount, simulation has emerged as an educational tool to augment clinical training. A variety of simulation modalities have been described in the literature, but no study has aimed to assess the use of simulation in liver transplantation fellowship training. METHODS: A 20-question survey detailing the use of simulation, including simulation modalities used and barriers to simulation use, was developed and distributed to 22 program directors for liver transplantation anesthesiology fellowships. An exploratory analysis was performed on multiple-choice and free-text responses. RESULTS: Thirteen program directors completed the survey and were included in our analysis. Most programs (61.5%) did not report the use of simulation for liver transplantation fellow training. Of the programs that did use simulation, four required it as a mandatory component of their curriculum. Task trainers and screen-based simulators were more commonly used by these programs. Faculty availability and interest, as well as a lack of an established curriculum, were cited as major limitations to simulation use. CONCLUSIONS: Simulation is an important component of anesthesiology trainee education, as evidenced by the requirement for simulation during residency by the American Council for Graduate Medical Education. Our findings suggest that simulation is an underutilized educational tool that we believe could greatly augment the training of liver transplantation anesthesiology fellows by providing exposure to a wide range of clinical challenges.

The use of transesophageal echocardiography to predict surgical complexity scoring system for degenerative mitral valve repair.

BACKGROUND: For severe mitral valve (MV) degenerative disease, repair is recommended. Prediction of repair complexity and referral to high volume centers can increase rates of successful repair. This study sought to demonstrate that TEE is a feasible imaging modality to predict the complexity of surgical MV repair. METHODS: Two hundred TEE examinations of patients who underwent MV repair (2009-2011) were retrospectively reviewed and scored by two cardiac anesthesiologists. TEE scores were compared to surgical complexity scores, which were previously assigned based on published methods. Kappa values were reported for the agreement of TEE and surgical scores. McNemar's tests were used to test the homogeneity of the marginal probabilities of different scoring categories. RESULTS: TEE scores were slightly lower (2[1,3]) than surgical scores (3[1,4]). The agreement was 66% between the scoring methods, with a moderate kappa (.46). Using surgical scores as the gold standard, 70%, 71%, and 46% of simple, intermediate and complex surgical scores, respectively, were correctly scored by TEE. P1, P2, P3, and A2 prolapse were easiest to identify with TEE and had the highest agreement with surgical scoring (P1 agreement 79% with kappa .55, P2 96% [kappa .8], P3 77% [kappa .51], A2 88% [kappa .6]). The lowest agreement between the two scores occurred with A1 prolapse (kappa .05) and posteromedial commissure prolapse (kappa .14). In the presence of significant disagreement, TEE scores were more likely to be of higher complexity than surgical. McNemar's test was significant for prolapse of P1 (p = .005), A1 (p = .025), A2 (p = .041), and the posteromedial commissure (p < .0001). CONCLUSION: TEE-based scoring is feasible for prediction of the complexity of MV surgical repair, thus allowing for preoperative stratification.

Critical Care Simulation Education Program During the COVID-19 Pandemic.

BACKGROUND: Coronaviruses are important emerging human and animal pathogens. SARS-CoV-2, the virus that causes COVID-19, is responsible for the current global pandemic. Early in the course of the pandemic, New York City became one of the world's "hot spots" with more than 250,000 cases and more than 15,000 deaths. Although medical providers in New York were fortunate to have the knowledge gained in China and Italy before it came under siege, the magnitude and severity of the disease were unprecedented and arguably under appreciated. The surge of patients with significant COVID-19 threatened to overwhelm health care systems, as New York City health systems realized that the number of specialized critical care providers would be inadequate. A large academic medical system recognized that rapid redeployment of noncritical providers into such roles would be needed. An educational gap was therefore identified: numerous providers with minimal critical care knowledge or experience would now be required to provide critical-level patient care under supervision of intensivists. Safe provision of such high level of patient care mandated the development of "educational crash courses." METHODS: The purpose of this special article is to summarize the approach adopted by the Institute for Critical Care Medicine and Department of Anesthesiology, Perioperative and Pain Medicine's Human Emulation, Education, and Evaluation Lab for Patient Safety and Professional Study Simulation Center in developing a training program for noncritical care providers in this novel disease. RESULTS: Using this joint approach, we were able to swiftly educate a wide range of nonintensive care unit providers (such as surgical, internal medicine, nursing, and advanced practice providers) by focusing on refreshing critical care knowledge and developing essential skillsets to assist in the care of these patients. CONCLUSIONS: We believe that the practical methods reviewed here could be adopted by any health care system that is preparing for an unprecedented surge of critically ill patients.

Does chronic atrial fibrillation induce cardiac remodeling?

AIM: The aim of this study was to compare cardiac structure and function in patients with chronic atrial fibrillation (CAF), as opposed to patients with paroxysmal atrial fibrillation (PAF), and normal control subjects. METHODS AND RESULTS: This study included 83 patients, divided into 3 groups: group A, 32 patients with CAF for ≥6 months; group B, 29 patients in sinus rhythm with a documented history of PAF; and group C, 22 patients without history of atrial fibrillation. Patients with CAF were older (71 years vs. 64 in group B, and 64 in group C). Apart from age, groups were clinically similar. After careful clinical evaluation, comprehensive echocardiography studies were performed including cardiac chambers' size, systolic and diastolic left ventricular function. Left atrium (LA) volume index was significantly larger in CAF than PAF and control patients: 39 ± 13 versus 34 ± 9 versus 25 ± 8 (P < 0.003). Left ventricular ejection fraction was lower in CAF: 53.8 ± 7 versus 61.6 ± 6.7 versus 58.4 ± 5.2% (P < 0.001). Isovolumic relaxation time was shorter in CAF, 65 ± 16 versus 82 ± 21 versus 81 ± 13 msec (P < 0.001). E/Vp was significantly greater in CAF 2.6 ± 0.8 versus 1.7 ± 0.4 versus 1.7 ± 0.5 (P < 0.001). Additional diastolic parameters were also significantly different. CONCLUSION: These findings demonstrate that in patients with CAF structural and functional cardiac changes occur. Patients with CAF as opposed to both normal subjects and patients with PAF have larger left atria and reduced systolic and diastolic left ventricular function.

Connexin40 imparts conduction heterogeneity to atrial tissue.

Impulse propagation in cardiac tissue is a complex process in which intercellular coupling through gap junction channels is a critical component. Connexin40 (Cx40) is an abundant gap junction protein that is expressed in atrial myocytes. Alterations in the expression of Cx40 have been implicated in atrial arrhythmogenesis. The purpose of the current study was to assess the role of Cx40 in atrial impulse propagation. High-resolution optical mapping was used to study conduction in the right and left atrial appendages of isolated Langendorff-perfused murine hearts. Wild-type (Cx40(+/+)), heterozygous (Cx40(+/-)), and knockout (Cx40(-/-)) mice, both adult and embryonic, were studied to assess the effects of reduced Cx40 expression on sinus node function and conduction velocity at different pacing cycle lengths (100 and 60 ms). In both adult and late-stage embryonic Cx40(+/+) mice, heterogeneity in CV was found between the right and left atrial appendages. Either partial (Cx40(+/-)) or complete (Cx40(-/-)) deletion of Cx40 was associated with the loss of conduction heterogeneity in both adult and embryonic mice. Additionally, sinus node impulse initiation was found to be ectopic in Cx40(-/-) mice at 15.5 days postcoitus, whereas Cx40(+/+) mice showed normal activation occurring near the crista terminalis. Our findings suggest that Cx40 plays an essential role in establishing interatrial conduction velocity heterogeneity in the murine model. Additionally, we describe for the first time a developmental requirement for Cx40 in normal sinus node impulse initiation at 15.5 days postcoitus.

Impulse initiation and conduction in the murine atria: a basis for future investigation of sinus node dysfunction.

The prevalence of atrial conduction defects and sinus node dysfunction increases with age. These age-related changes may play a critical role in establishing the substrate for the development of atrial fibrillation (AF), the most common sustained arrhythmia. Despite the association between atrial arrhythmias and age, little is known of the mechanisms that underlie changes in atrial electrophysiological function. Ongoing studies in our laboratory are focused on determining the mechanisms of atrial conduction defects associated with aging and disease. The purpose of this report is to present some initial studies of the murine sinus node and the approach we have taken to quantify conduction at the site of impulse initiation.

Heterogeneous connexin43 expression produces electrophysiological heterogeneities across ventricular wall.

Recently we found that electrophysiological (EP) heterogeneities between subepicardial and midmyocardial cells can form a substrate for reentrant ventricular arrhythmias. However, cell-to-cell coupling through gap junctions is expected to attenuate transmural heterogeneities between cell types spanning the ventricular wall. Because connexin43 (Cx43) is the principal ventricular gap junction protein, we hypothesized that transmural EP heterogeneities are in part produced by heterogeneous Cx43 expression across the ventricular wall. The left ventricles of eight dogs were sectioned to expose the transmural surface. To determine whether heterogeneous Cx43 expression influenced EP function, high-resolution transmural optical mapping of the arterially perfused canine wedge preparation was used to measure transmural conduction velocity (thetaTM), dV/dt(max), transmural space constant (lambdaTM), and transmural gradients of action potential duration (APD). Relative Cx43 expression, quantified by confocal immunofluorescence, was significantly lower (by 24 +/- 17%; P < 0.05) in subepicardial compared with deeper layers. Importantly, reduced subepicardial Cx43 was associated with transmural heterogeneities of EP function evidenced by selectively reduced subepicardial thetaTM (by 18 +/- 9%; P < 0.05) compared with deeper layers. In subepicardial regions, dV/dt(max) was fastest (by 19 +/- 15%) and lambdaTM was smallest (by 18.1 +/- 2%), which suggests that conduction slowing was attributable to localized uncoupling rather than reduced excitability. The maximum transmural APD gradients occurred in the same regions where Cx43 expression was lowest; this suggests that Cx43 expression patterns served to maintain APD gradients across the transmural wall. These data demonstrate that heterogeneous Cx43 expression is closely associated with functionally significant EP heterogeneities across the transmural wall. Therefore, Cx43 expression patterns can potentially contribute to arrhythmic substrates that are dependent on transmural electrophysiological heterogeneities.