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Numerous studies have shown that more visual features can be stored in visual short-term memory (VSTM) when they are encoded from fewer objects (Luck & Vogel, 1997, Nature, 390, 279-281; Olson & Jiang, 2002, Perception & Psychophysics, 64[7], 1055-1067). This finding has been consistent for simple objects with one surface and one boundary contour, but very few experiments have shown a clear performance benefit when features are organized as multipart objects versus spatially dispersed single-feature objects. Some researchers have suggested multipart object integration is not mandatory because of the potential ambiguity of the display (Balaban & Luria, 2015, Cortex, 26(5), 2093-2104; Luria & Vogel, 2014, Journal of Cognitive Neuroscience, 26[8], 1819-1828). For example, a white bar across the middle of a red circle could be interpreted as two objects, a white bar occluding a red circle, or as a single two-colored object. We explore whether an object benefit can be found by disambiguating the figure-ground organization of multipart objects using a luminance gradient and linear perspective to create the appearance of a unified surface. Also, we investigated memory for objects with a visual feature indicated by a hole, rather than an additional surface on the object. Results indicate the organization of multipart objects can influence VSTM performance, but the effect is driven by how the specific organization allows for use of global ensemble statistics of the memory array rather than a memory benefit for local object representations.

Machine learning (ML) has been increasingly used in medicine and neurosurgery. We sought to determine whether ML models can distinguish ruptured from unruptured aneurysms and identify features associated with rupture.We performed a retrospective review of patients with intracranial aneurysms detected on vascular imaging at our institution between 2002 and 2018. The dataset was used to train 3 ML models (random forest, linear support vector machine [SVM], and radial basis function kernel SVM). Relative contributions of individual predictors were derived from the linear SVM model.Complete data were available for 845 aneurysms in 615 patients. Ruptured aneurysms (n = 309, 37%) were larger (mean 6.51 mm vs. 5.73 mm; P = 0.02) and more likely to be in the posterior circulation (20% vs. 11%; P0.001) than unruptured aneurysms. Area under the receiver operating curve was 0.77 for the linear SVM, 0.78 for the radial basis function kernel SVM models, and 0.81 for the random forest model. Aneurysm location and size were the 2 features that contributed most significantly to the model. Posterior communicating artery, anterior communicating artery, and posterior inferior cerebellar artery locations were most highly associated with rupture, whereas paraclinoid and middle cerebral artery locations had the strongest association with unruptured status.ML models are capable of accurately distinguishing ruptured from unruptured aneurysms and identifying features associated with rupture. Consistent with prior studies, location and size show the strongest association with aneurysm rupture.

Background Prince George's County Maryland, historically a medically underserved region, has a population of 909 327 and a high incidence of cardiometabolic syndrome and hypertension. Application of level I evidence practices in such areas requires the availability of highly advanced cardiovascular interventions. Donabedian principles of quality of care were applied to a failing cardiac surgery program. We hypothesized that a multidisciplinary application of this model supported by partnership with a university hospital system could result in improved quality care outcomes. Methods and Results A 6‐month assessment and planning process commenced in July 2014. Preoperative, intraoperative, and postoperative protocols were developed before program restart. Staff education and training was conducted via team simulation and rehearsal sessions. A total of 425 patients underwent cardiac surgical procedures. Quality tracking of key performance measures was conducted, and 323 isolated coronary artery bypass grafting procedures were performed from July 2014 to December 2019. Key risk factors in our patient demographic were higher than the Society of Thoracic Surgeons national mean. Risk‐adjusted outcome data yielded a mortality rate of 0.3% versus 2.2% nationally. The overall major complication rate was lower than expected at 7.1% compared with 11.5% nationally. Readmission rate was less than the Society of Thoracic Surgeons mean for isolated coronary artery bypass grafting (4.0% versus 10.1%, P Conclusions Excellent outcomes in cardiac surgery are attainable following program renovation in an underserved region in the setting of low volume. The principles and processes applied have potential broad application for any quality improvement effort.

Purpose Retinopathy of prematurity is a leading cause of childhood blindness worldwide, but clinical diagnosis is subjective, which leads to treatment differences. Our goal was to determine objective differences in the diagnosis of plus disease between clinicians using an automated retinopathy of prematurity (ROP) vascular severity score. Design This retrospective cohort study used data from the Imaging and Informatics in ROP Consortium, which comprises 8 tertiary care centers in North America. Fundus photographs of all infants undergoing ROP screening examinations between July 1, 2011, and December 31, 2016, were obtained. Participants Infants meeting ROP screening criteria who were diagnosed with plus disease and treatment initiated by an examining physician based on ophthalmoscopic examination results. Methods An ROP severity score (1–9) was generated for each image using a deep learning (DL) algorithm. Main Outcome Measures The mean, median, and range of ROP vascular severity scores overall and for each examiner when the diagnosis of plus disease was made. Results A total of 5255 clinical examinations in 871 babies were analyzed. Of these, 168 eyes were diagnosed with plus disease by 11 different examiners and were included in the study. The mean ± standard deviation vascular severity score for patients diagnosed with plus disease was 7.4 ± 1.9, median was 8.5 (interquartile range, 5.8–8.9), and range was 1.1 to 9.0. Within some examiners, variability in the level of vascular severity diagnosed as plus disease was present, and 1 examiner routinely diagnosed plus disease in patients with less severe disease than the other examiners (P Conclusions We observed variability both between and within examiners in the diagnosis of plus disease using DL. Prospective evaluation of clinical trial data using an objective measurement of vascular severity may help to define better the minimum necessary level of vascular severity for the diagnosis of plus disease or how other clinical features such as zone, stage, and extent of peripheral disease ought to be incorporated in treatment decisions.

Background Variation in red blood cell (RBC) transfusion practices exists at cardiac surgery centers across the nation. We tested the hypothesis that significant variation in RBC transfusion practices between centers in our state's cardiac surgery quality collaborative remains even after risk adjustment. Methods Using a multiinstitutional statewide database created by the Maryland Cardiac Surgery Quality Initiative (MCSQI), we included patient-level data from 8,141 patients undergoing isolated coronary artery bypass (CAB) or aortic valve replacement at 1 of 10 centers. Risk-adjusted multivariable logistic regression models were constructed to predict the need for any intraoperative RBC transfusion, as well as for any postoperative RBC transfusion, with anonymized center number included as a factor variable. Results Unadjusted intraoperative RBC transfusion probabilities at the 10 centers ranged from 13% to 60%; postoperative RBC transfusion probabilities ranged from 16% to 41%. After risk adjustment with demographic, comorbidity, and operative data, significant intercenter variability was documented (intraoperative probability range, 4% –59%; postoperative probability range, 13%–39%). When stratifying patients by preoperative hematocrit quartiles, significant variability in intraoperative transfusion probability was seen among all quartiles (lowest quartile: mean hematocrit value, 30.5% ± 4.1%, probability range, 17%–89%; highest quartile: mean hematocrit value, 44.8% ± 2.5%; probability range, 1%–35%). Conclusions Significant variation in intercenter RBC transfusion practices exists for both intraoperative and postoperative transfusions, even after risk adjustment, among our state's centers. Variability in intraoperative RBC transfusion persisted across quartiles of preoperative hematocrit values.

Purpose Accurate image-based ophthalmic diagnosis relies on fundus image clarity. This has important implications for the quality of ophthalmic diagnoses and for emerging methods such as telemedicine and computer-based image analysis. The purpose of this study was to implement a deep convolutional neural network (CNN) for automated assessment of fundus image quality in retinopathy of prematurity (ROP). Design Experimental study. Participants Retinal fundus images were collected from preterm infants during routine ROP screenings. Methods Six thousand one hundred thirty-nine retinal fundus images were collected from 9 academic institutions. Each image was graded for quality (acceptable quality [AQ], possibly acceptable quality [PAQ], or not acceptable quality [NAQ]) by 3 independent experts. Quality was defined as the ability to assess an image confidently for the presence of ROP. Of the 6139 images, NAQ, PAQ, and AQ images represented 5.6%, 43.6%, and 50.8% of the image set, respectively. Because of low representation of NAQ images in the data set, images labeled NAQ were grouped into the PAQ category, and a binary CNN classifier was trained using 5-fold cross-validation on 4000 images. A test set of 2109 images was held out for final model evaluation. Additionally, 30 images were ranked from worst to best quality by 6 experts via pairwise comparisons, and the CNN’s ability to rank quality, regardless of quality classification, was assessed. Main Outcome Measures The CNN performance was evaluated using area under the receiver operating characteristic curve (AUC). A Spearman’s rank correlation was calculated to evaluate the overall ability of the CNN to rank images from worst to best quality as compared with experts. Results The mean AUC for 5-fold cross-validation was 0.958 (standard deviation, 0.005) for the diagnosis of AQ versus PAQ images. The AUC was 0.965 for the test set. The Spearman’s rank correlation coefficient on the set of 30 images was 0.90 as compared with the overall expert consensus ranking. Conclusions This model accurately assessed retinal fundus image quality in a comparable manner with that of experts. This fully automated model has potential for application in clinical settings, telemedicine, and computer-based image analysis in ROP and for generalizability to other ophthalmic diseases.

[Figure: see text] OBJECTIVES: Childhood blindness from retinopathy of prematurity (ROP) is increasing as a result of improvements in neonatal care worldwide. We evaluate the effectiveness of artificial intelligence (AI)–based screening in an Indian ROP telemedicine program and whether differences in ROP severity between neonatal care units (NCUs) identified by using AI are related to differences in oxygen-titrating capability. METHODS: External validation study of an existing AI-based quantitative severity scale for ROP on a data set of images from the Retinopathy of Prematurity Eradication Save Our Sight ROP telemedicine program in India. All images were assigned an ROP severity score (1–9) by using the Imaging and Informatics in Retinopathy of Prematurity Deep Learning system. We calculated the area under the receiver operating characteristic curve and sensitivity and specificity for treatment-requiring retinopathy of prematurity. Using multivariable linear regression, we evaluated the mean and median ROP severity in each NCU as a function of mean birth weight, gestational age, and the presence of oxygen blenders and pulse oxygenation monitors. RESULTS: The area under the receiver operating characteristic curve for detection of treatment-requiring retinopathy of prematurity was 0.98, with 100% sensitivity and 78% specificity. We found higher median (interquartile range) ROP severity in NCUs without oxygen blenders and pulse oxygenation monitors, most apparent in bigger infants (>1500 g and 31 weeks’ gestation: 2.7 [2.5–3.0] vs 3.1 [2.4–3.8]; P = .007, with adjustment for birth weight and gestational age). CONCLUSIONS: Integration of AI into ROP screening programs may lead to improved access to care for secondary prevention of ROP and may facilitate assessment of disease epidemiology and NCU resources.

A nearly linear contrast response function (CRF) is found in the lower level striate cortex whereas a steep, nonlinear increase at lower contrasts that gradually increases toward response saturation for higher contrasts is found in the higher level extrastriate cortex. This change of CRFs along the ventral cortical pathway indicates a shift from stimulus- and energy-dependent coding at lower levels to percept- and information-dependent coding at higher levels. The increase of nonlinearity at higher levels optimizes the extraction of perceptual information by amplifying responses to the ubiquitous low-contrast inputs in the environment. We used this difference of CRFs between lower and higher levels, particularly at lower contrasts (.0 to .30), as a tool to investigate examples of 2 lower level (simultaneous brightness and simultaneous tilt) and 2 higher level (Poggendorff and Ponzo) illusions. As predicted, the Poggendorff and Ponzo illusions yielded strong nonlinear increases in their CRFs compared to the more linear functions found for the simultaneous-brightness and simultaneous-tilt illusions. We conclude that the Poggendorff-Ponzo illusions rely more heavily on high-level, percept-dependent cortical processing than do the simultaneous-brightness-simultaneous-tilt illusions and, more generally, that differences between contrast-dependent changes may be a useful tool in determining the relative level of cortical processing of many other visual effects. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Studies have shown that people consistently remember seeing more of a studied scene than was physically present (e.g., Intraub & Richardson Journal of Experimental Psychology: Learning, Memory, and Cognition, 15, 179-187, 1989). This scene memory error, known as boundary extension, has been suggested to occur due to an observer's failure to differentiate between the contributing sources of information, including the sensory input, amodal continuation beyond the view boundaries, and contextual associations with the main objects and depicted scene locations (Intraub, 2010). Here, "scenes" made of abstract shapes on random-dot backgrounds, previously shown to elicit boundary extension (McDunn, Siddiqui, & Brown Psychonomic Bulletin & Review, 21, 370-375, 2014), were compared with versions made with extremal edges (Palmer & Ghose Psychological Science, 19, 77-84, 2008) added to their borders, in order to examine how boundary extension is influenced when amodal continuation at the borders' view boundaries is manipulated in this way. Extremal edges were expected to reduce boundary extension as compared to the same scenes without them, because extremal edge boundaries explicitly indicate an image's end (i.e., they do not continue past the view boundary). A large and a small difference (16 % and 40 %) between the close and wide-angle views shown during the experiment were tested to examine the effects of both boundary extension and normalization with and without extremal edges. Images without extremal edges elicited typical boundary extension for the 16 % size change condition, whereas the 40 % condition showed signs of normalization. With extremal edges, a reduced amount of boundary extension occurred for the 16 % condition, and only normalization was found for the 40 % condition. Our findings support and highlight the importance of amodal continuation at the view boundaries as a component of boundary extension.

Individuals consistently remember seeing wider-angle versions of previously viewed scenes than actually existed. The multi-source model of boundary extension (BE) suggests many sources of information contribute to this visual memory error. Color diagnosticity is known to affect object recognition with poorer recognition for atypically versus typically colored objects. Scenes with low-color diagnostic main objects and two versions of scenes with high-color diagnostic main objects (typically and atypically colored) were tested to determine if the reduced ability to identify the main object in a scene influences BE. Scenes were presented to one group of participants for 46 ms and another group for 250 ms. Each scene was followed by a mask and a request for a recognition response concerning the identity of the main object. The scene was then immediately presented again for testing and participants rated it as depicting a more close-up view, more wide-angle, or the same view as before. The study demonstrates that poorer encoding of main objects in scenes leads to increased BE, but trial-by-trial recognition accuracy had no relationship to BE magnitude. This finding provides further insight into the impact of task demand and main object recognition on BE.

Importance Retinopathy of prematurity (ROP) is a leading cause of childhood blindness worldwide. The decision to treat is primarily based on the presence of plus disease, defined as dilation and tortuosity of retinal vessels. However, clinical diagnosis of plus disease is highly subjective and variable. Objective To implement and validate an algorithm based on deep learning to automatically diagnose plus disease from retinal photographs. Design, Setting, and Participants A deep convolutional neural network was trained using a data set of 5511 retinal photographs. Each image was previously assigned a reference standard diagnosis (RSD) based on consensus of image grading by 3 experts and clinical diagnosis by 1 expert (ie, normal, pre–plus disease, or plus disease). The algorithm was evaluated by 5-fold cross-validation and tested on an independent set of 100 images. Images were collected from 8 academic institutions participating in the Imaging and Informatics in ROP (i-ROP) cohort study. The deep learning algorithm was tested against 8 ROP experts, each of whom had more than 10 years of clinical experience and more than 5 peer-reviewed publications about ROP. Data were collected from July 2011 to December 2016. Data were analyzed from December 2016 to September 2017. Exposures A deep learning algorithm trained on retinal photographs. Main Outcomes and Measures Receiver operating characteristic analysis was performed to evaluate performance of the algorithm against the RSD. Quadratic-weighted κ coefficients were calculated for ternary classification (ie, normal, pre–plus disease, and plus disease) to measure agreement with the RSD and 8 independent experts. Results Of the 5511 included retinal photographs, 4535 (82.3%) were graded as normal, 805 (14.6%) as pre–plus disease, and 172 (3.1%) as plus disease, based on the RSD. Mean (SD) area under the receiver operating characteristic curve statistics were 0.94 (0.01) for the diagnosis of normal (vs pre–plus disease or plus disease) and 0.98 (0.01) for the diagnosis of plus disease (vs normal or pre–plus disease). For diagnosis of plus disease in an independent test set of 100 retinal images, the algorithm achieved a sensitivity of 93% with 94% specificity. For detection of pre–plus disease or worse, the sensitivity and specificity were 100% and 94%, respectively. On the same test set, the algorithm achieved a quadratic-weighted κ coefficient of 0.92 compared with the RSD, outperforming 6 of 8 ROP experts. Conclusions and Relevance This fully automated algorithm diagnosed plus disease in ROP with comparable or better accuracy than human experts. This has potential applications in disease detection, monitoring, and prognosis in infants at risk of ROP.

The purpose of this study is to examine trends in mitral valve (MV) repair and replacement surgery using The Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS ACSD).The study population included isolated mitral valve operations performed between January 2000 and December 2007 at 910 hospitals participating in the STS ACSD. Patients with endocarditis, prior cardiac operation, shock, emergency operation, and concomitant coronary artery bypass graft or aortic valve surgery were excluded.During the 8-year study period, 58,370 patients underwent isolated primary MV operations. For patients with isolated mitral regurgitation (n = 47,126), the rate of MV repair (versus replacement) increased from 51% to 69% (p0.0001). Among patients having replacement (n = 24,404), there has been a pronounced decline in the use of mechanical valves: 68% to 37% (p0.0001). The operative mortality for MV replacement was consistently higher than that for repair (3.8% versus 1.4%), a finding that persisted after risk-adjustment (adjusted odds ratio 0.52, 95% confidence interval: 0.45 to 0.59; p0.0001). Among patients having elective isolated MV repair (n = 28,140), the operative mortality was 1.2%. For asymptomatic (class I) patients, operative mortality was 0.6%.This study documents several important trends in MV surgery, including the progressive adoption of mitral valve repair and increasing use of bioprosthetic replacement valves. Operative risks of MV repair are significantly lower than those for MV replacement. Operative mortality for isolated elective mitral valve repair is 1% in contemporary clinical practice.

Objective. Saphenous vein grafts (SVG) used for coronary artery bypass surgery (CABG) often develop a gradual luminal narrowing over the first year due to neointimal hyperplasia (NH). Although the basic science of NH is well studied, our clinical understanding of this issue is limited. The purpose of this cohort study was to investigate clinical risk factors for NH by monitoring luminal narrowing within SVG using multichannel CT angiography (CTA). Methods. Thirty patients underwent CABG involving SVG (N = 44) and arterial grafts (N = 36). Patient variables were recorded and the baseline quality of each conduit determined intraoperatively by analyzing surplus segments for intima-media thickness ratio (IMT) by histology and matrix metalloproteinase-2 by enzyme-linked immunosorbent assay. Percent luminal narrowing (%LN) was calculated for each patent graft by comparing the CTA appearance on day 5 to a repeat study at 1 y. Results. Compared with arterial grafts, SVG showed significantly higher IMT at baseline (0.9 ± 0.65 versus 0.22 ± 0.17, P < 0.0001) and more %LN over the first year (6.9 ± 7.5 versus 25.3 ± 13.3% LN, P< 0.0001). Of all of the measured variables, the only significant predictors of %LN included baseline IMT (r = 0.58, P = 0.002) and matrix metalloproteinase-2 levels (r = 0.60, P = 0.002) in SVG. Conclusions. The degree of NH at baseline, a phenomenon exclusive to SVG and not found in arterial grafts, was significantly related to the development of lumen loss in the conduit over the first year after CABG. The study of SVG using serial CTA may provide unique insights into the natural history of SVG remodeling and to identify factors that influence the long-term function of this conduit.

Aortic valve bypass is a technique used in high-risk patients with critical aortic stenosis that consists of placement of a conduit from the left ventricular apex to descending aorta. We describe the imaging appearances of this apicoaortic conduit on multidetector CT (MDCT).Each patient underwent retrospective ECG-gated MDCT using a 16-detector-row scanner several days after placement of an apicoaortic conduit. All images were assessed by two radiologists who reviewed the appearance of the apicoaortic conduit and any post-operative complications. Follow-up studies were available for several patients.Twelve patients (9 men, 3 women, mean age - 78 years) underwent evaluation and the conduit was visible in each. The valve within the conduit was visible in ten (91%) of the 11 patients who received intravenous contrast material. Common findings were periconduit outpouching and hypoperfusion involving the left ventricle. Complications included pericardial hemorrhage, hemothorax and ventricular pseudoaneurysm. Mild to moderate increase in wall thinning was identified in the three patients who underwent follow-up imaging.Aortic valve bypass with an apicoaortic conduit appears to be a feasible alternative to aortic valve replacement in high-risk patients. MDCT is an excellent method to assess the imaging features of such conduits.

Previous research has demonstrated the ability of diffuse red light to suppress activity in the magnocellular (M) visual pathway. An earlier psychophysical study found that a subset of nonpsychotic relatives of persons with schizophrenia showed the opposite effect when compared to healthy adults (Bedwell et al., 2003), suggesting a novel biobehavioral marker for the disorder. The present study attempted to replicate and explore the mechanism for this effect using fMRI. Results provide physiological evidence that the M pathway response to red light is in the opposite direction than expected in a subset of nonpsychotic relatives of persons with schizophrenia.

ObjectiveThe predominant mechanism of early graft failure after coronary artery bypass grafting remains in doubt. Aspirin administered in the initial hours after coronary artery bypass grafting improves graft patency, implicating prostanoid synthesis in the pathogenesis. We hypothesized that synergy between endothelial disruption in the venous conduit and aspirin resistance would cause vein graft failure.MethodsAspirin resistance, defined by diagnostic findings on at least two of three separate assays, was serially assessed in 225 patients undergoing off-pump coronary artery bypass grafting. Endothelial cell integrity was determined in surplus segments obtained from 408 vein grafts. The deposition of intraluminal thrombin within the vein was determined by comparing serum F1.2 levels between the coronary sinus and the aorta after grafting. Intraoperative blood flow in the grafts was measured with transit-time technology, and patency was assessed with electrocardiographically gated multichannel computed tomographic coronary angiography on day 5. Aspirin was the sole antithrombotic agent used during the study.ResultsThrombosed grafts (16/408) showed more endothelial cell loss at the time of grafting than did those grafts that remained patent (10.8% ± 21.5% vs 51.4% ± 39.1% integrity, P < .01). Aspirin resistance occurred in 67 patients (30%). Graft thrombosis was associated with aspirin resistance (P < .04) and reduced endothelial integrity (P < .01). These factors coexisted in 14 of 16 grafts that failed and were associated with elevated coronary sinus F1.2 levels.ConclusionAspirin resistance and relatively compromised venous endothelial cell integrity together marked patients whose vein grafts failed within days after off-pump coronary artery bypass grafting. These observations form a basis for identifying patients at risk and developing approaches to prevent vein injury or to selectively intervene in high-risk circumstances.

Background The Cox Maze III operation remains the gold standard for the surgical treatment of atrial fibrillation (AF). We report our experience using a flexible argon-powered metal cryoprobe for creation of the complete Cox-Maze III lesion set in patients with AF (the CryoMaze operation). Methods Beginning July 2002, 38 patients underwent the CryoMaze operation. Two patients had isolated CryoMaze procedures, whereas 36 patients had the CryoMaze performed in combination with coronary, valvular, or aortic surgery. All patients had electrocardiographic follow-up. Atrial fibrillation was continuous in 79%. Mean duration of AF before operation was 48 months. Results There were no complications related to the use of cryoenergy. There was 1 hospital death (2.6%) and no late deaths. At a mean follow-up of 12 months, 35 of 37 patients (95%) were in normal sinus rhythm. One patient required pacemaker implantation 3 months after surgery, and 1 patient refused follow-up. There have been no early or late thromboembolic events. Conclusions The CryoMaze operation reliably cures atrial fibrillation at medium term follow-up, with rates identical to those reported for the classic Cox-Maze III operation.

Background Tricuspid valve replacement (TVR) is a rarely needed operation. Choices between mechanical and biological prosthesis still generate controversy. We present our initial clinical experience with a stentless aortic root placed inverted in the tricuspid annulus. Methods Between August 2000 and September 2003, TVR for severe tricuspid insufficiency was performed in 8 patients. Indications were infective endocarditis (7) and iatrogenic damage (1). Mean age was 42.2 years old (20 to 58 years old). Five patients were male and 3 patients had a concomitant procedure (mitral valvuloplasty, coronary bypass grafting, and aortic valve replacement). A stentless aortic root, size 27 mm (n = 5) or 29 mm (n = 3) was placed inverted in the tricuspid position after the valsalva sinuses were scalloped. Interrupted 4-0 polypropylene sutures were used between the tricuspid valve annulus and the sewing ring. The struts equivalent on the stentless valve were anchored to the septal, anterior and posteroinferior wall of the right ventricle using 5-0 PTFE pledgeted sutures. Results Hospital survival was 100% and mean hospital stay was 12.5 days (3 to 18 days). Intraoperative and follow-up echocardiograms revealed no stenosis or insufficiency. Mean follow-up was 17.2 months (1–38 months). There were 3 late deaths due to continued IV drug use (n = 2) and end-stage renal failure (n = 1). Conclusions This is a novel surgical alternative for a very high risk population. Potential advantages over current options include minimization of blood contact with nonbiological surfaces, preservation of annular motion, freedom from anticoagulation, and a theoretical lower rate of calcification.

Background Saphenous vein graft failure after coronary artery bypass surgery may be as high as 5% to 10% in the first postoperative week. We hypothesized that identifying damage sustained by saphenous vein endothelium before grafting predicts early graft attrition after off-pump coronary artery bypass graft surgery. Methods Intraoperative graft flow, platelet function, and endothelial integrity were analyzed in 125 patients undergoing off-pump coronary artery bypass graft surgery. Endothelial integrity was assessed in an excess vein segment from each graft using immunohistochemistry (CD31 staining). Platelet function was monitored just before and immediately after revascularization and on postoperative days 1 and 3 using whole blood aggregometry, thrombelastography, and platelet activated clotting time. Platelet activation was monitored using flow cytometry. Intraoperative conduit blood flow, measured by transit time ultrasonography, was used to detect and rectify anastomotic problems. Early graft patency was determined on postoperative day 5 using gated multichannel computed tomography angiography. Results In 106 patients undergoing postoperative computed tomography evaluation, 10 vein grafts in 10 patients were discovered to have developed early thrombosis, representing 4% (10 of 217) of all vein grafts. Endothelial integrity was 10.75% ± 17.56% in 10 grafts that failed early compared with 51.45% ± 36.29% in patent grafts ( p = 0.04). Perioperative platelet function and graft flow did not differ significantly between the two groups. Conclusions Although endothelial disruption predicts early failure of bypass grafts, the importance of a hypercoaguable state and low graft flow as a cause of early graft thrombosis after off-pump coronary artery bypass graft surgery was not supported by our preliminary results. A means to assess, prevent, and treat intraoperative vein graft damage will likely improve early graft patency.

Objective To present the authors' 30-year experience with traumatic aortic rupture (TAR). Background Data TAR is a highly lethal injury. Most institutions manage a small number of cases, and most surgeons receive only modest exposure during training. Methods Between 1971 and 2001, the authors operated on 219 patients with a diagnosis of TAR. Diagnosis of TAR since 1994 has been based exclusively on the use of contrast-enhanced spiral computed tomography, with angiography reserved for equivocal cases (periaortic mediastinal hematoma without aortic wall abnormalities). Patients were divided according to surgical technique. Eighty-two patients (group A) were operated on with a clamp-and-sew technique. Sixty-four patients (group B) underwent surgery with the use of a passive shunt, and 73 patients (group C) were treated using heparin-less partial cardiopulmonary bypass. Results Mortality was 18 patients for group A (21.9%), 23 patients for group B (35.9%), and 13 patients for group C (17.8%) (P = .03). Paraplegia occurred in 15 of 64 survivors in group A (23.4%), 7 of 41 survivors in group B (17%), and 0 of 60 survivors in group C (P =.0005). Aortic occlusion without lower body perfusion for longer than 30 minutes (P =.004) and surgical technique without lower body bypass support (P = .0005) were associated with paraplegia. Conclusions Surgery for TAR based on spiral computed tomography screening and diagnosis is reliable. The use of heparin-less distal cardiopulmonary bypass in the authors' hands is safe and is associated with a reduced incidence of paraplegia.

The visibility of stationary visual phantoms and the grating induction (GI) effect were concurrently analyzed with both black and gray inspection areas (IA) using the same subjects with counterbalanced orders of measurements. Oblique inducing gratings were employed in order to compare the visibility of obliquely aligned and vertically misaligned appearances between the two phenomena. Aligned and misaligned phantom responses with a black IA were similar, whereas overall phantom visibility was severely suppressed when the IA was gray. In contrast, misaligned GI dominated with a gray IA, whereas aligned and misaligned GI responses were similar with a black IA. Phantoms appear to be related to visual mechanisms' selectively utilizing relative luminance information between the inducing grating and IA in a manner consistent with more global figural characteristics of the display (e.g., modal and amodal completion). On the other hand, GI may be predominantly due to locally operating brightness/contrast mechanisms.

Myocardial stress can result in myocellular phenotypic changes including enhanced activity of antioxidant enzyme systems. Accordingly, endogenous tissue antioxidant enzyme activity has been associated with resistance to cardiac ischemia and reperfusion injury. The present study was designed to determine if environmental perturbations could alter myocardial antioxidant enzyme (catalase) activity and function after ischemia. Isolated perfused rat hearts (Langendorff apparatus, 37 degrees C) were subjected to 20 min global ischemia (37 degrees C) and 40 min reperfusion. Rats studied immediately following shipment had increased myocardial catalase activity (1330 +/- 3.5 U/g, P0.05 vs quarantined control) and increased resistance to ischemia and reperfusion injury (end reperfusion developed pressure, DP 55 +/- 4.0 mm Hg, P0.05 vs quarantined control). However, control rats that were quarantined for 4 weeks exhibited a progressive decrease in catalase activity (760 +/- 10 U/g) for 3 weeks of quarantine. There was a concurrent decrease in resistance to myocardial ischemia and reperfusion injury (DP 40 +/- 3.6 mm Hg). Similarly, quarantined rats subjected to construction-related noise levels in excess of 90 dB (A scale) had increased myocardial catalase activity (1140 +/- 3.3 U/g, P0.05) and functional tolerance to ischemia and reperfusion (DP 66 +/- 3.3 mm Hg, P0.05). Finally, rats experiencing 90-dB noise levels for 2 days exhibited increased myocardial catalase activity (1125 +/- 30 U/g, P0.05) and myocardial ischemia and reperfusion injury tolerance (DP 62 +/- 1.7 mm Hg, P0.05). We conclude that variations in environmental conditions can relate to changes in antioxidant defense mechanisms and tolerance to myocardial ischemia and reperfusion injury in the rat.

In a three-line vernier acuity task, a central line was localized between two aligned line segments. Accuracy did not improve when the segments formed a unified amodally completed percept. In a two-line vernier acuity task, a line was localized below a target line placed next to a physically segmented flank stimulus. Shifts in mean points of subjective equality suggested that amodally completed segments influenced localization. Previous conflicting findings are explained by a representation that is available early to influence perceived alignment. However, position tuning is poor. This representation may be realized physiologically by interpolation responses between amodally completed segments.

Lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-alpha independently induce cardioprotection against ischemia in the rat at 24 h after administration, suggesting that endogenously synthesized TNF-alpha may play a role in LPS-induced protection. The purposes of this study were 1) to delineate the time course of LPS-induced cardiac functional protection against ischemia and its relation with myocardial and circulating TNF-alpha profile, 2) to examine whether prior protein synthesis inhibition abrogates the protection, and 3) to assess the effects of TNF-alpha inhibition and neutralization on the protection. Rats were treated with LPS (0.5 mg/kg i.p.). Cardiac functional resistance to normothermic global ischemia-reperfusion was examined at sequential time points after LPS treatment in isolated hearts by the Langendorff technique. Myocardial and circulating TNF-alpha was determined by enzyme-linked immunosorbent assay at 1-24 h after LPS treatment. Protection was apparent at 24 h, 3 days, and 7 days but not at 2 or 12 h. Maximal protection at 3 days was abolished by cycloheximide pretreatment (0.5 mg/kg i.p. 3 h before LPS treatment). Increases in myocardial and circulating TNF-alpha preceded the acquisition of protection. Dexamethasone pretreatment (4.0 or 8.0 mg/kg i.p. 30 min before LPS treatment) abolished peak increase in myocardial TNF-alpha and substantially suppressed circulating TNF-alpha (54.3 and 85.9% inhibition, respectively) without an influence on the maximal protection. Similarly, maximal protection was not affected by TNF binding protein (40 or 80 microg/kg i.v. immediately after LPS treatment). The results suggest that LPS-induced cardiac functional protection against ischemia is a delayed and long-lasting protective response that may involve de novo protein synthesis. Although LPS-induced increase in myocardial and circulating TNF-alpha precedes the delayed protection, it may not be required for the delayed protection.

Repetitive episodes of brief ischemia induce myocardial adaptation to prolonged ischemia. To investigate whether this myocardial adaptive response involves gene transcription and de novo protein synthesis, this study examined the effects of actinomycin D (ActD) and cycloheximide (Chx) on the cardioprotection induced by repeated ischemic preconditioning. Isolated, perfused working rat hearts underwent cyclic ischemia (CI, four 5-min ischemic intervals, 37 degrees C) with and without pretreatment with Chx (1.0 mg/kg, ip; translation inhibition) or ActD (1.5 mg/kg, ip; transcription inhibition) 3 hr prior to heart isolation. All hearts were subjected to 20 min global ischemia (37 degrees C) and 40 min reperfusion (I/R). Coronary effluent was assayed for creatine kinase (CK) activity. Myocardial tissue was homogenized and crude protein content determined. CI preconditioning improved postischemic recovery of cardiac output (CO; 48 +/- 5.1% vs 73 +/- 2.8% for control and CI, respectively, P0.05) and reduced CK release (61 +/- 8.5 U/L vs 38 +/- 4.2 U/L for control and CI, respectively, P0.05). The beneficial effects of CI preconditioning on myocardial function and cellular integrity were abolished by Chx while ActD had no effect. Myocardial protein content was increased in CI preconditioned myocardium relative to control hearts (5082 +/- 89 microg/g vs. 4459 +/- 260 microg/g, respectively, P0.05). Similarly, pretreatment with Chx but not ActD prevented the increase in myocardial protein content (Chx + CI, 4020 +/- 254 microg/g; ActD + CI, 5049 +/- 68 microg/g, P0.05 Chx + CI vs CI or ActD + CI). Myocardial dry/wet weight ratios were not different between groups (P0.05). We conclude that CI preconditioning induces protein synthesis-dependent myocardial protection against I/R injuries. CI-induced de novo protein synthesis in the myocardium appears to be regulated at the translational level rather than by gene transcription.

"Fast-track" (FT) cardiac surgery is popular in the private and university sectors. This study was designed to examine its safety and efficacy in the Department of Veterans Affairs elderly, male patient population, a population with multiple comorbid risk factors, often decreased social functioning, and impaired support systems.Time to extubation, hospital length of stay, perioperative morbidity, and mortality were studied in two consecutive cohorts undergoing cardiac operations requiring cardiopulmonary bypass before (pre-FT: n = 255, January 1992 to September 1993) and after (FT: n = 304, October 1993 to October 1995) institution of an FT protocol at a university-affiliated teaching Department of Veterans Affairs medical center. Preoperative risk factors, including a Department of Veterans Affairs risk-adjusted estimate of operative mortality, and perioperative surgical and anesthetic processes of care were evaluated.The mean Department of Veterans Affairs risk estimate of perioperative mortality was not different between the pre-FT and FT cohorts (3.5% versus 3.7%, p = 0.13). In the FT cohort, median time to extubation decreased significantly (19.2 versus 10.2 hours; p0.001) along with median surgical intensive care unit stay (96 versus 49 hours; p0.001) and total postoperative length of stay (222 versus 167 hours; p0.001). Median postoperative day of hospital discharge decreased from day 10 to 7 (p0.001). One patient (0.3%) required emergent reintubation directly related to early extubation. Reintubation for medical reasons was unchanged between pre-FT and FT groups (6.3% versus 5.0%; p = 0.48). Postoperative morbidity was similar between groups except for nosocomial pneumonia, the rate of which decreased significantly in the FT cohort (14.7% versus 7.3%; p0.005). Thirty-day (3.9% versus 4.6%; p = 0.69) and 6-month mortality (6.7% versus 6.9%; p = 0.91) were unchanged.An FT cardiac surgery protocol has been instituted in a university-affiliated teaching Department of Veterans Affairs medical center, with decreased length of stay and no significant increase in postoperative morbidity, 30-day mortality, or 6-month mortality. It was associated with a lower rate of nosocomial pneumonia, a finding that must be validated in a prospective study.

Sublethal endotoxemia attenuates cardiac functional injury from global ischemia but it is unknown whether endotoxemia can protect myocardium against infarction. Furthermore, increases in myocardial catalase and heat shock protein (HSP) following endotoxemia have been associated with cardiac ischemic protection. We therefore hypothesized that a 72-hr pretreatment with endotoxin (ETX) would reduce myocardial tissue necrosis in association with augmented catalase activity and stress protein expression. Rabbits were treated with normal saline or lipopolysaccharide (Salmonella typhimurium) at 10, 5, and 1 microgram/kg doses. Three days after saline or ETX injection they were subjected to 45 min of coronary artery occlusion followed by 3 hr of reperfusion. Area of necrosis (tetrazolium staining) was normalized to anatomic risk zone size (Evans blue staining). Catalase activity was measured by a standard assay and HSP 72 was assessed by immunohistochemistry. During regional ischemia and reperfusion there were no differences in heart rate or mean arterial blood pressure between groups. ETX treated rabbits had the same risk zone size as controls. Infarct size was reduced in the ETX treated rabbits at the 10 and 5 microgram/kg doses compared with control rabbits (17.5 +/- 1.5% and 22.2 +/- 3.1% vs 45.3 +/- 2.5%; P0.05) but no protective effect was observed at the 1.0 micrograms/kg dose (38.0 +/- 4.6%; P0.05 vs control). Catalase activity was not different between control and ETX (5 microgram/kg) treated groups (997.8 +/- 59.1 U/g vs 1099.6 +/- 69.3 U/g myocardium; P0.05) but endotoxin induced expression of myocardial HSP 72. We conclude that a single challenge with endotoxin can induce delayed myocardial protection against infarction in vivo. This delayed cardioprotective response involves enhanced stress protein expression without changes in myocellular catalase activity.

I NTRAOPERATIVE transesophageal echocardiography (TEE) is being used increasingly for monitoring of ventricular function and wall motion during coronary artery bypass grafting (CABG). Although the exact frequency of its use has not been well documented in the literature, a recent survey administered by the Society of Cardiovascular Anesthesiologists at their 1993 Annual Meeting indicated that nearly 39% of the respondents (n = 202) used TEE "routinely" during cardiac cases (although no distinction was made between CABG and valve surgery).* Although the respondents to this survey represent a biased sample of cardiovascular subspecialists, it appears that the intraoperative use of TEE has become popular. With the use of such a sensitive imagmg modality, the chance of detecting incidental abnormalities unrelated to the primary surgical procedure increases. A case is reported of an unsuspected finding on TEE that led to additional surgical intervention in an already high-risk patient undergoing CABG.

This study was conducted to assess the effect of priming on the Stroop task over time. Color-congruent, color-incongruent, and neutral stimuli were randomly presented. Five prime conditions were also used. The prime conditions included valid color, invalid color, valid word, and invalid word primes and no prime. Primes were presented to 8 subjects at varying stimulus onset asynchronies ranging from −200 msec., i.e., 200 msec. before the color-word stimulus, to 200 msec., i.e., 200 msec. after the color-word stimulus. Analysis suggested the facilitory or inhibitory effects of semantic information on the Stroop task are reduced when the prime follows the color-word stimulus by 200 msec. This implies 200 msec. are needed to make the proper color response. A model is proposed to account for the findings. Methodological considerations for studies using priming and the Stroop task are also discussed.

This study investigated the possibility of sex differences in spatial frequency processing by measuring contrast sensitivity and reaction time to spatial frequency in the same 20 men and 20 women. This is the first study to investigate sex differences in reaction time to spatial frequency and the first to study sex differences in contrast sensitivity and reaction time within the same participants. No sex differences were found in either contrast sensitivity or reaction time measures, suggesting that women and men process spatial frequency information similarly.

Moving phantom visibility was measured for subjects with a fundus classified as either lightly or darkly pigmented. The phantom-inducing pattern was a black-and-white square-wave grating drifting continuously from left to right, with a black horizontal occluder interrupting the middle of the grating. Moving phantom visibility was significantly reduced for darker relative to lighter pigmented subjects. The results show that fundus pigmentation can influence the perception of illusory contours and surfaces (i.e., phantoms). This finding supports and expands on previous research concerning fundus pigmentation influences on real contour perception.

Two experiments examined the ability to recognize a repeated figure in stimuli where only fragments of the figures were presented. Fragments were either closed or open regions presented either with or without an occluder that filled the spaces between the fragments (Experiment 1). Recognition performance was significantly better for open fragments, with or without an occluder, contrary to previous assertions that the occluder is the important factor for recognition. When stimulus size was varied, an occluder hindered recognition performance in the smallest size condition relative to unoccluded stimuli, which were equally easy to recognize across all size conditions (Experiment 2). The size results support the idea of size invariance in object naming. The difficulty in the smallest occluded condition is discussed in terms of differences in global and local processing depending on visual angle and sparsity.

Sublethal endotoxin (ETX) pretreatment of rats induces protection from cardiac ischaemia-reperfusion injury. This protective state is associated with increased endogenous myocardial catalase activity. Since tumour necrosis factor (TNF) is one mediator of ETX effects, we hypothesized that (TNF) pretreatment of the rat (30 μg/kg ip) 36 h prior to cardiac ischaemia-reperfusion could induced myocardial protection. We found that TNF administration increased both myocardial tolerance to ischaemia reperfusion injury (modified Langendorff, buffer perfusion, global, normothermic ischaemia) and myocardial catalase activity at 36 h. Moreover, we found that 6 h after TNF administration, myocardial hydrogen peroxide (H 2 O 2 , assessed by aminotriazole-H 2 O 2 inactivation of catalase) and myocardial neutrophil accumulation (assessed by histology) were both increased. When neutrophil function was inhibited either by neutrophil depletion (vinblastine) or by ibuprofen treatments of the rat before TNF, the protection previously apparent at 36 h was blocked. We conclude that TNF can induce myocardial resistance to ischaemia reperfusion injury. This protection is related to prior tissue neutrophil accumulation and concomitant increases in H 2 O 2 levels.

Background In-hospital mortality rates for left-sided infective endocarditis (IE) exceed 20%. We investigated the outcomes of an aggressive approach to mitral valve IE that emphasizes early surgical intervention and preferential performance of mitral valve repair. Methods We reviewed 89 consecutive operations in 87 patients for native mitral valve IE at a single institution from 2002 to 2007. Operations occurred promptly after completion of preoperative studies. Independent risk factors for death were investigated using multivariable logistic regression. Results Mitral valve repair was accomplished in 56 of 89 patients (63%). Perioperative mortality was 4.4% (n = 4). Survival rates at 1 and 5 years were 89.9% (80 of 89) and 82.0% (73 of 90). There was a survival benefit for repair vs replacement at 1 (p = 0.03) and 5 years (p = 0.0017). Repair vs replacement (odds ratio [OR], 0.2; 95% confidence interval [CI], 0.06 to 0.72), diabetes (OR, 4.43; 95% CI, 1.18 to 16.66), and renal failure (OR, 3.65; 95% CI, 1.3 to 12.91) were independent risk factors for late mortality. Among 59 patients with active IE, preoperative head computed tomography (CT) showed 29 (49%) had abnormalities, including 12 (41%) with intracerebral hemorrhage. The median interval was 4 days from admission to operation. The rate of permanent postoperative stroke was 1.1% (1 of 89). Conclusions These results support early surgical therapy for mitral valve IE. Head CT abnormalities do not warrant delay of operation. Mitral valve repair was associated with a long-term survival advantage compared with valve replacement.

Background— Aortic valve bypass (AVB; apicoaortic conduit) surgery relieves aortic stenosis (AS) by shunting blood from the apex of the left ventricle to the descending thoracic aorta through a valved conduit. We have performed AVB surgery as an alternative to conventional aortic valve replacement for high-risk AS patients. Methods and Results— Between 2003 and 2007, 31 high-risk AS patients were treated with AVB surgery. Twenty-two patients (71%) were undergoing reoperation with patent coronary bypass grafts, and 5 (16%) had a porcelain ascending aorta. The average age was 81 years. Cardiopulmonary bypass was used for 19 of 31 patients (61%); the median duration of cardiopulmonary bypass was 19 minutes. Cross-clamp time for all patients was 0 minutes. Perioperative mortality was 13% (4 of 31 patients); no perioperative deaths occurred in the last 16 consecutive patients. One patient experienced a stroke related to intraoperative hypotension. No strokes have occurred during follow-up. Renal function was unchanged after AVB (preoperative creatinine, 1.3±0.5 mg/dL; postoperative creatinine, 1.2±0.5 mg/dL). The mean gradient across the native aortic valve decreased from 43.5±15 to 10.4±5.4 mm Hg. Echocardiographically determined conduit flow expressed as a percentage of total cardiac output was 72±12%. Conclusions— AVB surgery is an important therapeutic option for high-risk patients with symptomatic AS. Ventricular outflow is distributed in a predictable fashion between the conduit and the left ventricular outflow tract, and AVB surgery reliably relieves AS. Stroke and renal dysfunction were uncommon.

ObjectiveMore than 200,000 aortic valve replacements are performed annually worldwide. We describe changes in the aortic valve replacement population during 10 years in a large registry and analyze outcomes.MethodsThe Society of Thoracic Surgeons National Database was queried for all isolated aortic valve replacements between January 1, 1997, and December 31, 2006. After exclusion for endocarditis and missing age or sex data, 108,687 isolated aortic valve replacements were analyzed. Time-related trends were assessed by comparing distributions of risk factors, valve types, and outcomes in 1997 versus 2006. Differences in case mix were summarized by comparing average predicted mortality risks with a logistic regression model. Differences across subgroups and time were assessed.ResultsThere was a dramatic shift toward use of bioprosthetic valves. Aortic valve replacement recipients in 2006 were older (mean age 65.9 vs 67.9 years, P < .001) with higher predicted operative mortality risk (2.75 vs 3.25, P < .001); however, observed mortality and permanent stroke rate fell (by 24% and 27%, respectively). Female sex, age older than 70 years, and ejection fraction less than 30% were all related to higher mortality, higher stroke rate and longer postoperative stay. There was a 39% reduction in mortality with preoperative renal failure.ConclusionsMorbidity and mortality of isolated aortic valve replacement have fallen, despite gradual increases in patient age and overall risk profile. There has been a shift toward bioprostheses. Women, patients older than 70 years, and patients with ejection fraction less than 30% have worse outcomes for mortality, stroke, and postoperative stay.

Efforts to reduce reperfusion injury have focused on exogenous therapies; however, endogenous attenuation of reperfusion injury can be induced by a single sublethal dose of endotoxin (ETX) prior to ischemia. The purposes of this study were to investigate (i) the early neutrophilendothelial (PMN-EC) adherence, (ii) the associated myocardial oxidant stress, (iii) the relationship of oxidant stress to antioxidant enzyme activity, and (iv) the correlation of increased antioxidant enzyme activity to myocardial recovery following ischemia/reperfusion (I-R) injury at 36 hr. Rats were administered a sublethal dose (2% of LD50) of endotoxin (500 μg/kg, ip, Salmonella typhimurium). At 6 hr, myocardial neutrophil accumulation (histology), hydrogen peroxide (H2O2) levels, and myocardial tissue glutathione (glutathione and oxidized glutathione) levels were determined. At 24 hr myocardial tissue glutathione levels and catalase (CAT) activity were assayed. At 36 hr, myocardial tissue superoxide dismutase, glutathione peroxidase, glutathione reductase, catalase, and glucose-6-phosphate dehydrogenase (G-6-PD) were assayed. At 36 hr, hearts were subjected to a standard (20 min, global, 37°C) ischemic insult followed by reperfusion. At 40 min of reperfusion, ventricular function was assessed (ventricular balloon; ventricular developed pressure +dP/dt, and t-dP/dt). Pretreatment with ETX resulted in (i) increased myocardial PMN accumulation at 6 hr (P < 0.05), (ii) increased tissue H2O2 levels at 6 hr (P < 0.05) and increased tissue glutathione oxidation at 24 hr (P < 0.05), (iii) increased myocardial CAT activity (U/mg protein) at 24 and 36 hr and increased G-6-PD activity (U/mg protein) at 36 hr (P < 0.05), and (iv) improved recovery of myocardial function following I-R injury at 36 hr (P < 0.05). We conclude that a single sublethal dose of endotoxin results in (i) early myocardial accumulation of neutrophils and associated increased H2O2 levels, (ii) a low-grade oxidant stress, (iii) subsequent increases in myocardial antioxidant enzyme activity, and (iv) enhanced myocardial functional recovery following ischemia-reperfusion injury.

Background Thoracic aortic injury remains a leading cause of death after blunt trauma. Thoracic aortic stents have the potential to treat aortic tears using a less invasive approach. We have accumulated the largest series of patients treated with blunt thoracic aortic injury over a 2-year period. Methods From July 2005 to present, 26 patients presenting with blunt aortic injury were treated with thoracic aortic endografting; these patients were retrospectively compared with the prior 26 patients presenting with similar aortic injury who were treated by open surgical repair. A Severity Characterization of Trauma score calculated for each patient predicts mortality based on severity of injury and degree of physiologic derangement on presentation. Results Patients treated with endografting had a significantly shorter length of stay, less intraoperative blood loss, decreased 24-hour blood transfusion, and lower incidence of postoperative tracheostomy compared with patients undergoing open repair. Survival in both groups was similar despite a trend toward higher injury severity among patients treated with endografting. Conclusions This early experience suggests that aortic endografting may provide a safe and efficient treatment of aortic tears that cardiac surgeons can be successful in employing.

Background Despite concerns about the adequacy of support provided by continuous-flow left ventricular assist devices (LVADs), direct comparisons of patient characteristics and outcomes between first-generation pulsatile and second-generation nonpulsatile LVADs are absent. We hypothesized that a nonpulsatile Jarvik 2000 LVAD (Jarvik Heart, Inc, New York, NY) would result in comparable outcomes to those of similarly ill patients implanted with a pulsatile LVAD (Novacor, WorldHeart Inc, Oakland, CA; and HeartMate XVE, Thoratec, Pleasanton, CA). Methods We retrospectively compared common pre-LVAD clinical characteristics and indicators of heart failure severity between 13 pulsatile and 14 nonpulsatile LVAD recipients. The outcomes analyzed were either heart transplantation, if the LVAD was intended as a bridge to transplantation, or hospital discharge if the intention was destination therapy. Results There was no significant difference between groups in pre-LVAD disease severity indicators. Nonpulsatile LVAD recipients had a significantly smaller body surface area (1.9 ± 0.2 m 2 versus 2.1 ± 0.2 m 2 , p = 0.04) and cardiopulmonary bypass time was also significantly shorter (61 ± 34 minutes versus 110 ± 49 minutes, p = 0.01). Aside from duration of initial intensive care unit stay (nonpulsatile, 10 ± 16 days; pulsatile, 14 ± 11 days; p = 0.02), there was no difference in post-LVAD outcomes: 10 of 14 nonpulsatile and 8 of 13 pulsatile LVAD patients achieved the combined end point ( p = 0.69). Conclusions Similarly ill congestive heart failure patients benefited equally well from either a nonpulsatile or a pulsatile LVAD. This may support an expanded role for nonpulsatile LVADs in the treatment of severe heart failure.

Background Debate continues between on-pump or off-pump approach for coronary artery bypass grafting (CABG). We used off-pump coronary artery bypass grafting (OPCAB) as a tool within a decision-making algorithm driven by the patient-related factors of coronary anatomy and comorbidity. Our analysis presents this decision algorithm and describes outcomes using this approach. Methods From January 2000 to December 2003, 592 consecutive patients undergoing isolated CABG were assigned by one surgeon to a technique: on-pump CABG or OPCAB according to (1) anatomy and (2) predicted risk. Anatomic factors against OPCAB were target vessel size less than 1.25 mm, calcification, poor quality, intramyocardial location, and multiple stenoses. Given that OPCAB could be performed safely, patients in the moderate risk range, ie, those elderly with multiple comorbidities, were preferentially treated using OPCAB. Results The OPCAB group had higher predicted 30-day mortality compared with the on-pump CABG group, consistent with the protocol's intent. However, morbidity and mortality were similar between on-pump CABG and OPCAB. The OPCAB patients received the same number of internal mammary artery grafts but fewer distal grafts. Mortality and observed to expected ratios were favorable for both groups and below those The Society of Thoracic Surgeons' predicted for OPCAB. Conclusions Matching surgical strategy to patient-related factors and needs resulted in excellent outcomes. Our data support the use of a protocol based on patient characteristics to drive the surgeon's choice between an on-pump CABG or OPCAB approach. As such, OPCAB can be viewed as a tool to be used by the surgeon developing a best practice in treating coronary artery disease.

Nonspecific primary allograft dysfunction is an important cause of perioperative death in cardiac transplant recipients. We report a case of severe nonspecific allograft dysfunction that was ultimately reversible after 18 days of biventricular mechanical circulatory support. Allograft recovery was echocardiographically recognized by a positive inotropic response to isoproterenol and milrinone. This case illustrates the potential for recovery of even extreme allograft dysfunction.

Previous research has suggested that genetic loading for schizophrenia is related to a dysfunctional magnocellular (M) subcortical visual pathway—responsible for processing movement and location. However, data substantiating this mechanism remains inconclusive. The present study used a novel technique to selectively suppress the M system in order to investigate the impact of genetic loading for schizophrenia on its functioning. A visual backward masking task was administered to 28 healthy first-degree relatives of persons with schizophrenia and 31 healthy controls. The task was administered on both a red and neutral background, as diffuse red light has been shown to selectively suppress the M system in basic vision research. On a location condition of backward masking, controls demonstrated reduced accuracy on the red compared to the neutral background. In contrast, relatives did not display differential performance between the two backgrounds. The differential effect on the two groups appears to be attributable to a difference in activity of the M pathway. Performance in the relatives was consistent with the notion of a hyperactive M pathway. D 2002 Elsevier Science B.V. All rights reserved.

Inflammation induces the expression of angiogenic growth factors in tissues, which leads to microvascular growth. Bacterial lipopolysaccharide (LPS) provokes a transient inflammatory response in the heart and induces delayed cardiac resistance to post-ischemic contractile dysfunction. In this study, we examined: 1) the effects of LPS on myocardial expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), 2) whether an increase in the density of myocardial microvessels follows the expression of angiogenic growth factors, and 3) the effect of LPS on myocardial resistance to infarction and its relationship with microvascular growth. Rats were treated with LPS (from Salmonella typhimurium, 0.5 mg/kg i.p.). The expression of bFGF and VEGF in the myocardium was examined at 6 and 12 h after LPS treatment by immunofluorescent staining. Myocardial capillary and arteriole densities were determined 3 days after LPS treatment by morphometry, using immunofluorescent staining of von Willebrand factor (a marker protein of endothelial cells) and alpha-smooth muscle actin (a marker protein of smooth muscle cells). To examine cardiac resistance to infarction, hearts were subjected to 40 min of regional ischemia and 2 h of reperfusion by reversible occlusion of left coronary artery at 3 days after LPS treatment. LPS induced cardiac bFGF and VEGF at 6 and 12 h after treatment. The expression of these growth factors was followed by an increase in myocardial capillary density (2032 +/- 78/mm2 vs. 1617 +/- 47/mm2 in saline control, P < 0.05), but not arteriole density, at 3 days. Meanwhile, infarct size was significantly reduced by LPS preconditioning (infarct/left ventricle 12.3 +/- 1.04% vs. 21.7 +/- 1.65% in saline control, 43% reduction, P < 0.05). These results suggest that LPS preconditioning induces cardiac bFGF and VEGF, and an increase in myocardial capillary density. This increased myocardial capillary density is associated with a reduced infarct size after in vivo regional ischemia-reperfusion.

Reduced exposure during minimally invasive valve operations poses new difficulties in intraoperative management. Transesophageal echocardiography improves intraoperative management. During a minimally invasive aortic valve replacement, we encountered unexpected hypotension due to mechanical compression of the right ventricle against the sternum. Transesophageal echocardiography facilitated rapid diagnosis of this problem. Surgeons performing these procedures should be aware of this potential problem.

Myocardial tolerance to ischemia and reperfusion (I/R) injury can be achieved by either acute or delayed cardioprotective mechanisms. Ischemic preconditioning has been demonstrated to be a powerful acute cardioprotective stimulus. We have reported that lipopolysaccharide (LPS) pretreatment induces delayed myocardial adaptation to I/R injury. To optimize myocardial protection, we examined the ability of delayed myocardial adaptation to enhance acute ischemic preconditioning in the isolated working rat heart. Male Sprague-Dawley rats were divided into control, acute [transient ischemia (TI); 5-min global ischemia, 37 degrees C], delayed (LPS; 500 micrograms/kg i.p.), or combined (LPS + TI) cardioprotective groups. Delayed cardioprotection involved LPS injection 72 h before heart isolation. All hearts were subjected to 20-min global ischemia (37 degrees C) and 30-min reperfusion. Coronary effluent collected during reperfusion was assayed for creatine kinase (CK) activity. Both TI and LPS treatment improved postischemic aortic flow recovery (29 +/- 4.5 and 44 +/- 4.0%, respectively; P < 0.05, LPS vs. TI) compared with control hearts (11 +/- 2.2%; P < 0.05, TI or LPS vs. control). When TI was applied to LPS-treated hearts (LPS + TI), aortic flow recovery was further enhanced (57 +/- 3.8%; P < 0.05 vs. TI or LPS alone). CK release during 20 and 30 min of reperfusion was decreased in all treated hearts compared with control hearts (P < 0.05). These results indicate that delayed myocardial adaptation and acute ischemic preconditioning independently activate protective mechanisms against ischemia. Enhanced protection occurs when induced delayed mechanisms are combined with acute cardioprotective stimuli, which optimize postischemic myocardial function and reduce myocellular necrosis.

The authors have shown that stimulation of cardiac alpha 1-adrenoceptors confers immediate cardioprotection in the isolated rat heart against post-ischemic dysfunction, and have recently demonstrated that in vivo treatment of rats with norepinephrine (NE) induces cardiac heat shock protein 72 and myocardial adaptation to ischemia 24 h after treatment. To characterize the delayed myocardial adaptive response induced by NE further, the present study examined its time course and effects of adrenoceptor antagonism and protein synthesis inhibition on this adaptive response during optimal myocardial protection. Rats were treated with NE (3.1 mumol/kg, i.p.) or normal saline (0.4 ml, i.p.), and hearts isolated at 2, 4, 24, 72 and 168 h after injection. Isolated hearts were subjected to 25 min of normothermic global ischemia and 40 min of reperfusion by the Langendorff technique, and left ventricular developed pressure (LVDP) was assessed. There was no difference in baseline LVDP among groups. Post-ischemic LVDP recovered to 44.7 +/- 2.1 mmHg in pooled saline control. LVDP was significantly improved in hearts isolated at 4, 24 and 72 h after injection of NE (66.3 +/- 3.8, 68.6 +/- 2.7 and 72.6 +/- 8.3 mmHg, respectively, P0.05 v control) but not in hearts isolated at 2 or 168 h. Effects of antecedent adrenoceptor antagonism and protein synthesis inhibition were examined in hearts isolated at 72 h after NE treatment. Prazosin pretreatment (2.4 mumol/kg, i.p.) abolished the delayed myocardial adaptive response induced by NE at 72 h (post-ischemic LVDP 48.3 +/- 6.1 mmHg, P0.05 v control) while propranolol pretreatment (3.4 mumol/kg, i.p.) had no effect (post-ischemic LVDP 67.3 +/- 3.7 mmHg, P0.05 v control). Cycloheximide pretreatment (3.6 mumol/kg, i.p.) also abolished the beneficial effect of NE at 72 h (post-ischemic LVDP 50.2 +/- 6.0 mmHg, P0.05 v control). In conclusion, administration of NE to rats can induce delayed and sustained cardioprotection against post-ischemic myocardial dysfunction. NE-induced myocardial adaptation to ischemia at 72 h is mediated by alpha 1-adrenoceptors and appears to require protein synthesis.

Background Colon perforation has been previously described after solid organ transplantation. Since the inception of the lung transplant program at the University of Colorado 60 isolated lung transplantations have been performed. Four of these patients have suffered spontaneous colonic perforation. Methods The case history of each lung transplant patient with a colon perforation and the literature were reviewed. Results An increased incidence of colon perforation in lung transplant patients was identified. Diverticulitis was found to be the predominant cause, and an association with steroids was noted. The two deaths in this series were in patients receiving high-dose steroids in whom invasive Aspergillus infections developed. Conclusions Careful screening of the gastrointestinal tract before transplantation is advocated. A steroid-sparing immunosuppressive regimen is recommended. All lung transplant patients with abdominal complaints require an aggressive work-up, and surgeons should have a low threshold for laparotomy. Conservative surgical principles, including resection of the perforated segment of colon and proximal end-colostomy rather than primary anastomosis, are necessary for the optimal outcome.

Objective: Previous studies have demonstrated that norepinephrine (NE) confers immediate cardioprotection against ischemia and reperfusion injuries. The present study tests the hypothesis that in vivo treatment with NE induces delayed cardioprotection against postischemic dysfunction in the rat heart which is associated with expression of c-fos and heat shock protein (HSP) 70 in the myocardium. Methods: Rats were treated with NE (3.1 μmol/kg, ip) and hearts isolated and perfused with a modified Langendorff technique 2 or 24 h after injection. Left ventricular developed pressure (LVDP) and left ventricular end-diastolic pressure (LVEDP) were recorded during 25 min normothermic global ischemia and 40 min reperfusion. Total RNA was extracted from left ventricular tissue at various time points and Northern hybridization was applied to detect c-fos and HSP70 mRNAs. Expression and distribution of c-fos and HSP72 proteins in the myocardium were examined by immunohistochemical staining. Results: In vivo NE treatment improved postischemic recovery of both LVDP and LVEDP in the hearts isolated at 24 h after treatment but not in those isolated at 2 h. LVDP was 68.9 ± 4.8 mmHg in NE 24 h group at the end of reperfusion in comparison to 43.6 ± 2.9 mmHg in saline control group ( P < 0.01). Pretreatment with prazosin abolished NE-induced cardioprotection while propranolol pretreatment had no effect. Northern analysis demonstrated rapid and transient increases in c-fos and HSP70 mRNAs in the myocardium after NE treatment. Accumulation of c-fos protein was observed at 3 h and increased amount of HSP72 protein was demonstrated at 24 h in the myocardium. Pretreatment of rats with prazosin eliminated NE-induced increase in cardiac HSP70 mRNA. Conclusions: The results suggest that in vivo treatment with NE upregulates the expression of c-fos and HSP70 in the myocardium and induces delayed protection against postischemic myocardial dysfunction in the isolated rat heart. Induction of both the expression of cardiac HSP70 and the delayed cardioprotection by NE appears to be mediated by α 1 adrenoceptors.

The purpose of this article is to report our short- and intermediate-term follow-up of cardiac transplantation for congenital heart disease and cardiomyopathy in children (age greater than 6 months), adolescents, and young adults. Thirty patients (ages 8 months to 24 years) with end-stage heart failure have undergone cardiac transplantation in our program: 12 (40%) for postoperative end-stage heart failure, 9 (30%) as primary treatment for congenital heart disease, 5 (17%) for dilated cardiomyopathy, and 4 (13%) for restrictive/hypertrophic cardiomyopathy. Nineteen patients (63%) had undergone prior operations; 4 patients received transplants for failed Fontan procedures. Induction therapy with antithymocyte therapy was used routinely, and long-term immunosuppression was by cyclosporine and azathioprine alone. Rejection surveillance/diagnosis was based on echocardiographic criteria. Posttransplantation follow-up ranges from 3 to 78 months. Operative mortality was 3.3% (1/30). No patients have been diagnosed with either accelerated allograft atherosclerosis or posttransplantation lymphoproliferative disease. We conclude that cardiac transplantation may be performed with excellent early and intermediate-term results.

Abstract Catecholamines have been implicated in the phenomenon of ischemic preconditioning. We have previously demonstrated that ischemic preconditioning against postischemic mechanical dysfunction in the isolated rat heart is mediated by the α 1 -adrenergic receptor. The purpose of this study was to delineate the signal transduction of preconditioning distal to the α 1 -adrenergic receptor. Our results suggest that (1) transient ischemia and α 1 -adrenergic receptor–induced preconditioning is inhibited by protein kinase C (PKC) antagonists, (2) functional protection against global ischemia/reperfusion injury can be induced by infusion of diacylglycerol, the second messenger of the α 1 -adrenergic pathway, and (3) transient ischemia and α 1 -adrenergic preconditioning are both characterized by similar translocation of PKC-δ to the sarcolemma of myocardium. These findings suggest that PKC is an effector of preconditioning in the isolated rat heart.