Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We assessed limit to cardiac compensation during isovolemic hemodilution (HD) in 14 anesthetized dogs. Radioactive microspheres were used to evaluate myocardial blood flow (MBF) and its transmural distribution (endo/epi). Myocardial O2 consumption (MVO2) and percent lactate extraction were determined. Coronary vasodilator reserve was assessed from reactive hyperemic responses. Dogs were divided into group 1, with intact left anterior descending coronary artery (LAD), and group 2, with critical stenosis of LAD. Measurements were obtained at baseline and during graded HD (Hespan) until cardiac failure (CF). CF occurred at lower hematocrit in group 1 compared with group 2 (9 +/- 1 vs. 17 +/- 1%). In group 1, MBF increased during HD to maintain MVO2 constant; increases in MBF were transmurally uniform until CF, when decreased endo/epi and lactate production suggested subendocardial ischemia. Coronary vasodilator reserve decreased progressively during HD and was absent at CF. In group 2, stenotic LAD demonstrated constant MBF (resulting in decreased MVO2) during HD. At CF, these responses along with reduced endo/epi and lactate production indicated local myocardial ischemia. We conclude that 1) with normal coronary circulation, cardiac function was well maintained over a wide range of hematocrits because increases in MBF were transmurally uniform and sufficient to maintain myocardial oxygenation: CF occurred during extreme HD when MBF became maldistributed, resulting in subendocardial ischemia; 2) critical coronary stenosis impaired coronary vascular adjustment to HD and reduced significantly tolerance of left ventricle to HD; and 3) present findings underscore the importance of recruitment of coronary vasodilator reserve in preserving total and regional myocardial oxygenation during HD.
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PMID:Limit to cardiac compensation during acute isovolemic hemodilution: influence of coronary stenosis. 834 51

In this study we addressed the question of whether the measurement of cardiac Troponin I (cTnI) is able to reflect beneficial effects of hypertonic-hyperoncotic solutions after transient cardiac arrest. Ten pigs were anaesthetized and cardiac arrest was induced by electric fibrillation. After 5 minutes of global ischemia, cardiac arrest was reversed by electric defibrillation. Upon return of spontaneous circulation 5 animals received hypertonic-hyperoncotic solutions (10% Hydroxyethylstarch 200/0.5 and 7.2% NaCl). The other animals received equivalent volumes of physiological saline. We observed that cTnI serum levels of animals treated with hypertonic-hyperoncotic solutions were significantly lower than those treated with saline. We conclude that hypertonic-hyperoncotic solutions may have cardioprotective effects.
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PMID:Hypertonic-hyperoncotic solutions decrease cardiac troponin I concentrations in peripheral blood in a porcine ischemia-reperfusion model. 1148 33

Newer, minimally invasive catheter-based endovascular technology utilizing stent grafts are currently being evaluated for abdominal aortic aneurysm (AAA) repair. A retrospective review of all (3 years) consecutive, non-ruptured elective AAA repairs was undertaken to document the results of AAA surgical repair in a modern cohort of patients to allow a contemporary comparison with the evolving endoluminal data. One hundred twenty-one AAAs were identified in a male veteran population. Mean age was 68.5 +/-7.7 years. Medical history review showed hypertension in 55%, heart disease in 73.5%, peripheral vascular disease in 21%, stroke and transient ischemic attacks in 22%, diabetes mellitus in 7%, renal insufficiency in 10%, and smoking history in 80%. The AAA size was documented with ultrasound (5.2 +/-1.3 cm, n=40) and computed tomography (5.6 +/-1.3 cm, n=100). Fifty-nine percent had angiography. Intraoperative end points included an operative time of 165 +/-6.3 minutes from incision to dressing placement. A Dacron tube graft was used in 78%, the remaining were Dacron bifurcated grafts. A suprarenal clamp was used in 8% for proximal aortic control with juxtarenal aneurysms. A pulmonary-artery catheter was placed in 69%. A transverse incision was used in 69% of patients and a midline incision was used in the rest. Estimated blood loss was 1505 +/-103 mL; cell saver blood returned 754 +/-53 mL; crystalloid/Hespan 4771 +/-176 mL; banked packed red blood cells 0.75 +/-0.11 U. Time to extubation was, in the operating room (78.5%), on the day of the operation (5.0%), postoperative day (POD) 1 (12.4%), POD2 (1.7%), POD3 (0.8%), and one case was performed with epidural anesthesia only. Postoperative end points included a 30-day mortality rate of 1.6% (two patients). Postoperative morbidity included wound dehiscence 0.8%; sepsis, urinary tract infection, wound infection, leg ischemia, ischemic colitis, and stroke each had an incidence of 1.6%; myocardial infarction, congestive heart failure, pneumonia, re-operation for suspected bleeding, and ileus or bowel obstruction occurred with an incidence of 3.3%. No significant increase in serum creatinine levels was noted. Time to enteral fluids/nutrition was 3.5 +/-0.08 days. Patients were out of bed to a chair or walking by 1.3 +/-0.06 days postoperatively. The length of stay in the intensive care unit (ICU) was 2.0 +/-0.12 days and postoperative hospital stay was 6.6 +/- 0.33 days. Transfusion requirement for the hospital stay was 1.6 +/-0.2 U per patient. This review highlights a cohort of male veteran patients with significant cardiac co-morbidity who have undergone repair with a conventional open technique and low mortality and morbidity rates. This group had rapid extubation, time to oral intake, and ambulation. In addition, ICU and hospital stays were relatively short.
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PMID:Abdominal aortic aneurysm repair. 1156 37

This study determines the systemic and microvascular hemodynamic consequences of administering a low dose sodium nitrite after fluid resuscitation from hemorrhagic shock. Hemodynamic responses to hemorrhagic shock and resuscitation were studied in the hamster window chamber model. Moderated hemorrhage was induced by arterial controlled bleeding of 50% of the blood volume (BV) and the hypovolemic state was maintained for 1h. Volume restitution was performed by infusion of 25% of BV using Hextend (6% Hetastarch 670kDa in lactated electrolyte solution) 10min after fluid resuscitation 100microl of specific concentrations of sodium nitrite were infused. The experimental groups were named based on the nitrite concentration used, namely: 0microM, 10microM and 50microM. Systemic parameters, microvascular hemodynamics and capillary perfusion (functional capillary density, FCD) were followed during entire protocol. Exogenous 10microM nitrite maintained systemic and microhemodynamic conditions post fluid resuscitation from hemorrhagic shock, compared to 50microM or no nitrite. A moderated increase in plasma nitrite during the early phase of resuscitation reversed arteriolar vasoconstriction and increased capillary perfusion and venous return, improving central cardiac function. Nitrite effects on resistance vessels, directly influenced intravascular pressure redistribution, sustained blood flow, and prevented tissue ischemia. In conclusion, increasing nitrite plasma bioavailability after fluid resuscitation from hemorrhagic shock can be a potential therapy to enhance microvascular perfusion and to improve overall outcome.
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PMID:Low dose nitrite enhances perfusion after fluid resuscitation from hemorrhagic shock. 1980 38