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Reversible Ischemia (reversible + ischemia)
Selected AbstractsAcute Effect of Cerivastatin on Cardiac Regional Ischemia in a Rat Model Mimicking Off-Pump Coronary SurgeryJOURNAL OF CARDIAC SURGERY, Issue 6 2005Koki Nakamura M.D. The aims of this study were to investigate the optimal duration of coronary occlusion for making reversible ischemia and to examine whether cerivastatin increases myocardial tolerance against prolonged coronary occlusion. Methods: Study 1,Male Sprague-Dawley rats (350 to 450 g) underwent temporary occlusion of either left anterior descending artery (LAD; for 3, 5, 7.5, 10, 12.5, 15, or 20 min) or circumflex artery (CX; for 5, 10, or 15 min). Study 2,Rats were divided into two groups, control and cerivastatin groups, which had 0.1 mg/kg cerivastatin intravenously after anesthesia. LAD was occluded for 10, 15, or 20 minutes. In the both studies, hearts were stained to determine the area at risk (AR) and infarcted (IF) area 24 hours after reperfusion. Results: In LAD occlusion, IF/AR increased in a time dependent manner: 4.5 ± 3.2%, 9.7 ± 5.2%, 17.2 ± 3.0%, 16.8 ± 2.7%, 23.9 ± 9.5% (p < 0.01 vs. 3 min), 62.4 ± 2.9% (p < 0.0001), and 63.4 ± 2.9% (p < 0.0001) at 3, 5, 7.5, 10, 12.5, 15, and 20 min, respectively. Also in CX, IF/AR increased with time: 14.3 ± 2.3%, 25.9 ± 2.1%, and 40.9 ± 6.2% (p < 0.001 vs. 5 min) at 5, 10, and 15 min, respectively. Cerivastatin significantly reduced IF/AR at 15 minutes (43.7 ± 6.2%) and at 20 minutes (44.6 ± 5.3%) compared to control (62.4 ± 2.9% and 60.6 ± 2.5%, respectively, p < 0.05). Conclusion: Cerivastatin increased myocardial tolerance after prolonged coronary occlusion over 10 minutes, which was considered to be the upper limit for creating a regional reversible ischemia in rats. [source] Predictive Value of T-wave Abnormalities at the Time of Emergency Department Presentation in Patients with Potential Acute Coronary SyndromesACADEMIC EMERGENCY MEDICINE, Issue 6 2008Kathy B. Lin BA Abstract Objectives:, T-wave abnormalities on electrocardiograms (ECGs) are common, but their ability to predict 30-day cardiovascular outcomes at the time of emergency department (ED) presentation is unknown. The authors determined the association between T-wave abnormalities on the presenting ECG and cardiovascular outcomes within 30 days of presentation in patients with potential acute coronary syndromes (ACSs). Methods:, This was a secondary analysis of a prospective cohort study of ED patients that presented with a potential ACS. Patients were excluded if they had a prior myocardial infarction, ST-segment elevation or depressions, right or left bundle branch block, or Q-waves on the initial ECG. Data included demographics, medical and cardiac history, and ECG findings including the presence or absence of T-wave flattening, inversions of 1,5 mm, and inversions >5 mm. Investigators followed the hospital course for admitted patients, and 30-day follow-up was performed on all patients. The main outcome was a composite of death, acute myocardial infarction, revascularization, coronary stenosis greater than 50%, or a stress test with reversible ischemia. Results:, Of 8,298 patient visits, 5,582 met criteria for inclusion: 4,166 (74.6%) had no T-wave abnormalities, 721 (12.9%) had T-wave flattening in two or more leads, 659 (11.8%) had T-wave inversions of 1,5 mm, and 36 (0.64%) had T-wave inversions >5 mm. The composite endpoint was more common in patients with T-wave flattening (8.2% vs. 5.7%; p = 0.0001; relative risk [RR] = 1.4; 95% confidence interval [CI] = 1.1 to 1.9), T-wave inversions 1,5 mm (13.2% vs. 5.7%; p = 0.0001; RR = 2.4; 95% CI = 1.8 to 3.1), and T-wave inversions >5 mm (19.4% vs. 5.7%; p = 0.0001; RR = 3.4; 95% CI = 1.7 to 6.1), or any T-wave abnormality (10.8% vs. 5.7%; p = 0.0001; RR = 1.9; 95% CI = 1.6 to 2.3), even after adjustment for initial troponin. This association also existed in the subset of patients without known coronary artery disease. Conclusions:, In patients with potential ACS presenting to the ED, T-wave abnormalities are associated with higher rates of 30-day cardiovascular events. [source] Apoptosis and Necrosis in the Ischemic Zone Adjacent to Third Degree BurnsACADEMIC EMERGENCY MEDICINE, Issue 6 2008Adam J. Singer MD Abstract Objectives:, Burns are characterized by a central zone of necrosis surrounded by a zone of potentially reversible ischemia. The authors explored the contribution of necrosis and apoptosis to cell death in the zone of ischemia. Methods:, A previously established rat contact thermal injury model that utilizes a brass comb to produce four distinctive burns sites separated by three "interspaces" of unburned skin was used. The interspaces represent the zone of stasis or ischemia while the burn sites represent the zone of coagulation. With this model, most unburned interspaces progress to necrosis over 2 to 3 days. Full-thickness 3-mm biopsies were obtained from the interspaces, burns, and normal skin controls at 30 minutes, 24 hours, and 48 hours after injury. Slides were stained with hematoxylin and eosin as well as activated cleaved caspase-3 (CC3a) for evidence of apoptosis and high-mobility group box 1 (HMGB1) for evidence of necrosis. Results:, Necrosis was not seen at 30 minutes, but was found in a large number of cells within the epidermis, sebaceous glands, and follicles at 24 and 48 hours. Faint nuclear CC3a staining indicative of apoptosis was present in a minority of cells within the epidermis, dermal fibroblasts, dermal follicles, and dermal sebaceous glands at 30 minutes and to a lesser degree at 24 and 48 hours. Conclusions:, Both early apoptosis and delayed necrosis are present in the zone of ischemia, contributing to injury progression. Necrosis appears to play a larger role than apoptosis in injury progression in the comb burn model. [source] Coronary steal syndrome with coil embolization of a large LIMA side branch: Radionuclide evidence for reversible ischemiaCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2005Nasser Abdo MD Abstract This case presents the controversy over coronary artery steal syndrome following bypass surgery when a large branch of the left internal mammary artery (LIMA) is not ligated. A discussion of previous attempts to understand the physiology of this anatomy is compared with case reports of objective evidence for ischemia that resolves following occlusion of the LIMA side branch. © 2005 Wiley-Liss, Inc. [source] Computed Tomography Coronary Angiography for Rapid Disposition of Low-risk Emergency Department Patients with Chest Pain SyndromesACADEMIC EMERGENCY MEDICINE, Issue 2 2007Judd E. Hollander MD Background Patients with recent normal cardiac catheterization are at low risk for complications of ischemic chest pain. Computed tomography (CT) coronary angiography has high correlation with cardiac catheterization for detection of coronary stenosis. Therefore, the investigators' emergency department (ED) incorporated CT coronary angiography into the evaluation of low-risk patients with chest pain. Objectives To report on the 30-day cardiovascular event rates of the first 54 patients evaluated by this strategy. Methods Low-risk chest pain patients (Thrombolysis In Myocardial Infarction [TIMI] score of 2 or less) without acute ischemia on an electrocardiogram had CT coronary angiography performed in the ED. If the CT coronary angiography was negative, the patient was discharged home. The main outcomes were death and myocardial infarction within 30 days of ED discharge, as determined by telephone follow up and record review. Data are presented as percentage frequency of occurrence with 95% confidence intervals (CIs). Results Of the 54 patients evaluated, after CT coronary angiography, 46 patients (85%) were immediately released from the ED, and none had cardiovascular complications within 30 days. Eight patients were admitted after CT coronary angiography: one had >70% stenosis, five patients had 50%,69% stenosis, and two had 0,49% stenosis. Three patients had further noninvasive testing; one had reversible ischemia, and catheterization confirmed the results of CT coronary angiography. All patients were followed for 30 days, and none (0; 95% CI = 0 to 6.6%) had an adverse event during index hospitalization or at 30-day follow up. Conclusions When used in the clinical setting for the evaluation of ED patients with low-risk chest pain, CT coronary angiography may safely allow rapid discharge of patients with negative studies. Further study to conclusively determine the safety and cost effectiveness of this approach is warranted. [source] | ||||||||||