80 research outputs found
Flexible fiberoptic pericardioscopy for the diagnosis of pericardial disease
Pericardiocentesis provides an etiologic diagnosis for pericardial effusions approximately 25% of the time. In seven patients with evidence of a large pericardial effusion of unknown origin without cardiac tamponade, a flexible fiberoptic bronchoscope was inserted through a subxiphoid incision after the effusion was drained. Pericardioscopy allowed visualization of all pericardial surfaces and made it possible to perform selective biopsy not limited to a subxiphoid window. It is a safe procedure that can permit distinction among benign, malignant and tuberculous origins of pericardial effusion
Doppler echocardiographic demonstration of the differential effects of right ventricular pressure and volume overload on left ventricular geometry and filling
AbstractTo compare the effects of isolated right ventricular pressure and volume overload on left ventricular diastolic geometry and filling, 11 patients with primary pulmonary hypertension, 11 patients with severe tricuspid regurgitation due to tricuspid valve resection and 11 normal subjects were studied with use of Doppler echocardiography techniques. Right ventricular systolic overload in primary pulmonary hypertension resulted in substantial leftword ventricular septal shift that was most marked at end-systole and early diastole and decreased substantially by end-diastole. Right ventricular diastolic overload after tricuspid valve resection resulted in maximal leftward ventricular septal shift at end-diastole sparing end-systole and early diastole. The early diastolic distortion of left ventricular geometry associated with right ventricular pressure overload resulted in prolongation of isovolumetric relaxation of the left ventricle (129 ± 39 ms) and a reduction in early diastolic finding compared with values in normal subjects.Late diastolic distortion of left ventricular geometry associated with right ventricular volume overload had no influence on the duration of left ventricular isovolumetric relaxatoon (52 ± 32 ms) but caused a reduction in the atrial systolic contribution to late distolic filling of the left ventricle compared with values in normal sujects. In patients with right ventricular pressure overload, 52 ± 16% of left ventricular filling occurred in early diastole compared with 78 ± 11% in patients with right ventricular volume overload (p < 0.001). The differential effects of systolic and diastolic right ventricular overload on the pattern of left ventricular filling appear to bt related to the timing of leftward ventricular septal displacement
Reduced atrial contribution to left ventricular filling in patients with severe tricuspid regurgitation after tricuspid valvulectomy: A Doppler echocardiographic study
AbstractPatients undergoing valvulectomy for isolated tricuspid valve endocarditis offer the unique opportunity to study the effects of acquired right ventricular volume overload on left ventricular filling in persons free of pulmonary hypertension and preexisting left heart disease. Eleven patients who had undergone total or partial removal of the tricuspid valve were compared with 11 age-matched control subjects; Doppler echocardiographic techniques were used to quantify changes in left ventricular filling and to relate them to changes in left ventricular and left atrial geometry caused by right ventricular and right atrial distension.The late diastolic fractional transmitral flow velocity integral, a measure of the left atrial contribution to left ventricular filling, was significantly decreased in patients undergoing tricuspid valvulectomy compared with control subjects (0.22 ± 0.11 versus 0.32 ± 0.09; p < 0.04). Severe tricuspid regurgitation in these patients resulted in marked right atrial distension, reversal of the normal interatrial septal curvature and compression of the left atrium such that left atrial area was significantly smaller than in control subjects (5.9 ± 2.2 versus 8.6 ± 1.2 cm2/m2; p < 0.005).Acting as a receiving chamber, the left ventricle was maximally compressed by the volume-overloaded right ventricle in late diastole coincident with the timing of atrial systole, resulting in a significant increase in the left ventricular eccentricity index compared with that in control subjects (1.35 ± 0.14 versus 1.03 ± 0.1; p < 0.001). Thus, right ventricular volume overload due to severe tricuspid regurgitation results in left heart geometric alterations that decrease left atrial preload, impair left ventricular receiving chamber characteristics and reduce the atrial contribution to total left ventricular filling
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Mitochondrial transplantation for therapeutic use
Mitochondria play a key role in the homeostasis of the vast majority of the bodyâs cells. In the myocardium where mitochondria constitute 30 % of the total myocardial cell volume, temporary attenuation or obstruction of blood flow and as a result oxygen delivery to myocardial cells (ischemia) severely alters mitochondrial structure and function. These alterations in mitochondrial structure and function occur during ischemia and continue after blood flow and oxygen delivery to the myocardium is restored, and significantly decrease myocardial contractile function and myocardial cell survival. We hypothesized that the augmentation or replacement of mitochondria damaged by ischemia would provide a mechanism to enhance cellular function and cellular rescue following the restoration of blood flow. To test this hypothesis we have used a model of myocardial ischemia and reperfusion. Our studies demonstrate that the transplantation of autologous mitochondria, isolated from the patientâs own body, and then directly injected into the myocardial during early reperfusion augment the function of native mitochondria damaged during ischemia and enhances myocardial post-ischemic functional recovery and cellular viability. The transplanted mitochondria act both extracellularly and intracellularly. Extracellularly, the transplanted mitochondria enhance high energy synthesis and cellular adenosine triphosphate stores and alter the myocardial proteome. Once internalized the transplanted mitochondria rescue cellular function and replace damaged mitochondrial DNA. There is no immune or auto-immune reaction and there is no pro-arrhythmia as a result of the transplanted mitochondria. Our studies and those of others demonstrate that mitochondrial transplantation can be effective in a number of cell types and diseases. These include cardiac and skeletal muscle, pulmonary and hepatic tissue and cells and in neuronal tissue. In this review we discuss the mechanisms leading to mitochondrial dysfunction and the effects on cellular function. We provide a methodology for the isolation of mitochondria to allow for clinical relevance and we discuss the methods we and others have used for the uptake and internalization of mitochondria. We foresee that mitochondrial transplantation will be a valued treatment in the armamentarium of all clinicians and surgeons for the treatment of varied ischemic disorders, mitochondrial diseases and related disorders
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Preliminary Biomarkers for Identification of Human Ascending Thoracic Aortic Aneurysm
Background: Human ascending thoracic aortic aneurysms (ATAAs) are life threatening and constitute a leading cause of mortality in the United States. Previously, we demonstrated that collagens α2(V) and α1(XI) mRNA and protein expression levels are significantly increased in ATAAs. Methods and Results: In this report, the authors extended these preliminary studies using highâthroughput proteomic analysis to identify additional biomarkers for use in whole blood realâtime RTâPCR analysis to allow for the identification of ATAAs before dissection or rupture. Human ATAA samples were obtained from male and female patients aged 65±14 years. Both bicuspid and tricuspid aortic valve patients were included and compared with nonaneurysmal aortas (mean diameter 2.3 cm). Five biomarkers were identified as being suitable for detection and identification of ATAAs using qRTâPCR analysis of whole blood. Analysis of 41 samples (19 small, 13 mediumâsized, and 9 large ATAAs) demonstrated the overexpression of 3 of these transcript biomarkers correctly identified 79.4% of patients with ATAA of â„4.0 cm (P<0.001, sensitivity 0.79, CI=0.62 to 0.91; specificity 1.00, 95% CI=0.42 to 1.00). Conclusion: A preliminary transcript biomarker panel for the identification of ATAAs using whole blood qRTâPCR analysis in men and women is presented
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Derivation and Validation of a Preoperative Prediction Rule for Delirium After Cardiac Surgery
Backgroundâ Delirium is a common outcome after cardiac surgery. Delirium prediction rules identify patients at risk for delirium who may benefit from targeted prevention strategies, early identification, and treatment of underlying causes. The purpose of the present prospective study was to develop a prediction rule for delirium in a cardiac surgery cohort and to validate it in an independent cohort.
Methods and Resultsâ Prospectively, cardiac surgery patients â„60 years of age were enrolled in a derivation sample (n=122) and then a validation sample (n=109). Beginning on the second postoperative day, patients underwent a standardized daily delirium assessment, and delirium was diagnosed according to the confusion assessment method. Delirium occurred in 63 (52%) of the derivation cohort patients. Multivariable analysis identified 4 variables independently associated with delirium: prior stroke or transient ischemic attack, Mini Mental State Examination score, abnormal serum albumin, and the Geriatric Depression Scale. Points were assigned to each variable: Mini Mental State Examination â€23 received 2 points, and Mini Mental State Examination score of 24 to 27 received 1 point; Geriatric Depression Scale >4, prior stroke/transient ischemic attack, and abnormal albumin received 1 point each. In the derivation sample, the cumulative incidence of delirium for point levels of 0, 1, 2, and â„3 was 19%, 47%, 63%, and 86%, respectively (C statistic, 0.74). The corresponding incidence of delirium in the validation sample was 18%, 43%, 60%, and 87%, respectively (C statistic, 0.75).
Conclusionsâ Delirium occurs frequently after cardiac surgery. Using 4 preoperative characteristics, clinicians can determine cardiac surgery patientsâ risk for delirium. Patients at higher delirium risk could be candidates for close postoperative monitoring and interventions to prevent delirium
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