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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The best management for patients requiring CABG with severe calcification of the thoracic aorta has not be established. To clamp ascending aorta in such cases produce cerebral embolization, aortic dissection or mural laceration. We reported a 60-year-old male for unstable angina with LMT lesion. Emergency CABG using IABP was performed with femoral cannulation, moderate hypothermia and induced ventricular fibrillation. His postoperative course was uneventful and coronary arteriography revealed a satisfactory patent graft of the RITA to the LAD system.
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PMID:[A successful report of emergency CABG for severe calcified thoracic aorta--the porcelain aorta]. 177 87

Systemic hypothermia at 25 degrees-28 degrees C without chemical cardioplegia was used in 908 patients undergoing coronary artery bypass grafting. Local coronary artery flow was interrupted only during grafting of a distal anastomosis. Systemic perfusion pressure was maintained at 80-100 mmHg, hematocrit at 20%-25%, and pCO2 and pH were monitored during hypothermia according to the alpha-stat principle, while the left ventricle was vented routinely. Proximal anastomoses were performed just before extracorporeal circulation was started by only partially occluding the ascending aorta. Preoperatively 61.9% of the patients had had a myocardial infarction, and 44% had unstable angina. In 14% a severe lesion of the main stem of the left coronary artery was present. Left ventricular function was moderately depressed in 25% and severely depressed in 8% of the patients. Forty-eight patients (5.3%) were aged 70 years or older. The mean number of grafts placed per patient was 3.3. Perioperative myocardial infarction occurred in 3%. Death due to left ventricular failure occurred in 0.4%. No left ventricular assist devices were needed; an intra-aortic balloon pump was used in 1%; positive inotropic support was required in 3.8% of the patients. These results indicate that systemic hypothermia alone provides safe myocardial protection and in certain cases may be the method of choice, particularly if aortic cross clamping or administration of cardioplegic solution is contraindicated. In addition, this method provides rapid revascularization of a severely ischemic zone, as present after unsuccessful PTCA procedures.
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PMID:Myocardial protection by simple systemic hypothermia without aortic occlusion. 226 41

Cardioplegic myocardial protection has become the standard for coronary artery bypass. In contrast, we report 500 consecutive coronary artery bypass operations with intermittent aortic clamping for distal anastomoses, left ventricular venting, and 30 degrees C hypothermia. Average patient age was 62 years (range of 30 to 89 years). The number of patients who had urgent or emergency operations was 194 (39%); 251 patients had unstable angina, and 123 others had preinfarction angina (pain at rest in the hospital); 27 had evolving myocardial infarction. The average number of grafts was 3.3 per patient, and the average ischemic time was 7.65 minutes per graft. There were five hospital deaths (1%); none resulted from poor myocardial protection that caused low cardiac output. Only three survivors (0.6%) required a balloon pump to be weaned from cardiopulmonary bypass: two had acute infarctions preoperatively, and the other had an ejection fraction of 0.30 and intractable atrial arrhythmias. Only two other patients (0.4%) received any inotropic infusions postoperatively. Eighteen patients (3.6%) had a perioperative infarction. These results, particularly the virtual absence of postoperative inotropic support, in unselected patients of whom 80% had acute coronary syndromes, indicate that intermittent ischemia can provide excellent myocardial protection for coronary bypass. Brief periods of intermittent ischemia alleviate concern about cardioplegic protection via occluded coronaries or internal mammary grafts and provide a simple and safe option for myocardial protection during coronary artery bypass.
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PMID:Coronary artery bypass without cardioplegia. 349 33

Although it is well established that coronary revascularization can reverse exercise-induced ischemic dysfunction, the effects on resting ventricular performance are controversial. From a group of 183 patients receiving surgical therapy for ischemic heart disease, 166 underwent bypass graft arteriography at an average of 7 to 14 days postoperatively. In 149 patients, satisfactory preoperative and postoperative biplane left ventriculograms were obtained. Regional wall motion was assessed by the 100 segment method of Sheehan and Dodge, and a perioperative change in shortening greater than 2 standard deviations of normal variability over 20 or more adjacent segments was considered significant. Ninety-five patients had stable or progressive angina, 88 had medically refractory unstable angina, 155 were in New York Heart Association Class IV, and 37 had a preoperative left ventricular ejection fraction of less than 0.4. Myocardial integrity was preserved with crystalloid cardioplegia and topical hypothermia. Seven hundred ninety-eight bypass grafts were performed (522 vein grafts and 276 mammary artery grafts), and 13 patients had concomitant left ventricular aneurysmectomy. Hospital mortality was 2.2%. The overall early graft patency rate was 95.9% (93.7% for vein grafts and 100% for mammary arteries). Only one patient had a decrement in regional wall motion, and 51 (37%) had significant postoperative improvement (27 in the unstable angina group and 24 in the stable angina group); in the patients with improved regional wall motion, ejection fraction increased by an average of 0.18 (p less than 0.01). Ejection fraction also improved after aneurysmectomy, and the increment seemed to result from both a reduction in end-diastolic volume and improved regional wall motion. Thus, reversible ischemic myocardial dysfunction appears to be common in the general population of patients undergoing coronary artery bypass grafting; 40% of patients with unstable angina and 34% of those with stable angina can be expected to have improved regional wall motion after successful revascularization. Finally, ventricular aneurysm resection significantly enhances left ventricular performance as assessed by ventriculographic ejection fraction.
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PMID:The effects of coronary revascularization on left ventricular function in ischemic heart disease. 406 32

Hypothermic potassium cardioplegia has become the most popular technique for myocardial preservation during coronary revascularization. However, an older technique continues to yield comparable results with some potential advantages. Myocardial preservation was achieved with systemic hypothermia to 28 degrees C, pericardial cooling, elective ventricular fibrillation, maintenance of systemic perfusion pressure between 80 and 100 mm Hg, routine left ventricular venting, and local vessel isolation during distal anastomoses without aortic occlusion. Proximal anastomoses were performed prior to atrial cannulation and cardiopulmonary bypass. Nonemergency isolated bypass grafting was performed in 500 consecutive patients, of whom 51% had had a prior myocardial infarction, 24% had unstable angina, and 21% had left main coronary stenosis. Primary grafting was performed in 483 patients and reoperations in 17. The mean number of grafts per patient was 3.8. Perioperative myocardial infarction occurred in 1.8%. Hospital mortality was 0.4%. Late follow-up was obtained for all survivors at a mean postoperative interval of 17.8 months. All survivors were asymptomatic or improved over their preoperative status. The 3 year actuarial survival rate was 95.8%, equivalent to that for the matched general population. Of 287 male patients under age 65, 68.4% were working preoperatively and 69.5% postoperatively. This technique provides results comparable to bypass grafting with cardioplegia and may be useful when aortic occlusion or administration of cardioplegic solutions is not desirable.
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PMID:Noncardioplegic myocardial preservation for coronary revascularization. 661 56

Does the use of warm-body perfusion in elderly patients with severe cerebrovascular disease lead to a higher incidence of stroke, due to hypotension secondary to low systemic vascular resistance? Two thousand, three hundred eighty-three (2,383) consecutive myocardial revascularizations were performed (1987-1992) using warm-body (perfusion 37 degrees C), cold-heart surgery (cold cardioplegic arrest). The perfusion pressure was maintained between 50-70 torr; hematocrit was kept around 20%. Prospective data during hospitalization revealed 23 operative deaths (1%), and 24 patients (1%) who developed new neurological signs after surgery. The latter formed three groups: Group I consisted of six patients with severe neurological deficits, who never regained consciousness and died after support systems withdrawal. Group II included 14 patients with postoperative clinical evidence of focal cerebral infarction (9 had hemiplegia, 2 had visual disturbance, and 3 showed alteration of memory), all of whom had residual defects at discharge; Group III was composed of four patients with minor neurological deficits after surgery (hemiparesis, gait disturbance, mental changes) which had cleared up by discharge. These data were compared retrospectively with 1605 patients (1980-1986) undergoing myocardial revascularization with moderate (25-30 degrees C) hypothermia and the same surgical team and operative techniques. Both groups had similar preoperative demographics except the warm group included more elderly patients, higher numbers with unstable angina and poor ejection fraction, and more frequent use of a mammary artery conduit. Neurological complications were 1% and 1.3% for the normothermic and hypothermic perfusion groups respectively. Incremental risk factors of stroke remain: age over 70 years, diffuse atherosclerosis of the aorta, carotid occlusive disease, and severe hypotension during perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Neurological complications during myocardial revascularization using warm-body, cold-heart surgery. 804 89

Profound hypothermia with elective ventricular fibrillation and total circulatory arrest was used in a patient undergoing coronary artery bypass grafting (CABG) with severe calcification of the ascending aorta. A 76-year-old woman with unstable angina was referred for coronary revascularization. Ascending aorta was severely calcified with the exception of limited region of proximal ascending aorta, and the coronary arteriography showed high-grade obstruction of the left anterior descending (LAD) and dominant right coronary artery (RCA). The left internal thoracic artery was anastomosed to the LAD, and the saphenous vein graft to the RCA under systemic moderate hypothermia and elective ventricular fibrillation. During the proximal anastomosis of the saphenous vein graft to the non-calcified ascending aorta, profound hypothermia and circulatory arrest was instituted for 11 minutes. The wean from extracorporeal circulation was successful, and the postoperative course was uneventful.
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PMID:[Coronary revascularization using profound hypothermia with elective ventricular fibrillation and total circulatory arrest]. 828 28

Forty-two patients with an ejection fraction of 0.20 or less underwent coronary artery bypass grafting from 1986 to 1990 using a method of myocardial protection we term "centigrade cardioplegia," combining single-dose, cold, crystalloid cardioplegia, systemic hypothermia, and local hypothermia. Thirty-day mortality was 4.8% (2/42). Perioperative morbidity included two myocardial infarctions (4.8%) and one stroke (2.4%), which fully resolved. Postoperative left ventricular function improved (left ventricular ejection fraction, 0.157 +/- 0.028 to 0.226 +/- 0.085; p < 0.0002), as did New York Heart Association class (3.4 +/- 0.73 to 1.8 +/- 0.63; p < 0.0001) and Canadian class (3.3 +/- 0.81 to 0.61 +/- 0.92). Survival, 88% at 1 year, declined to 68% at 3 years and 34% at 6 years. This high-risk group had very acceptable short-term results, indicating adequate intraoperative myocardial protection. Four clinical variables were associated with long-term survival: (1) chief complaint of pain only (p = 0.05), (2) history of unstable angina (p = 0.04), (3) Canadian class less than IV (p = 0.05), and (4) New York Heart Association class less than IV (p = 0.05). Reduced survival, although not statistically significant (p = 0.07), was noted for right ventricular ejection fraction of 0.30 or less. These factors may help predict which patients with severe left ventricular dysfunction will benefit from revascularization.
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PMID:Coronary bypass with ejection fraction of 0.20 or less using centigrade cardioplegia: long-term follow-up. 837 19

Between August 1986 and March 1993, 124 patients (102 men; mean age of 59 years) underwent myocardial revascularization with the use of at least one free internal mammary artery (FIMA). This group represents 4.5% of the 2725 coronary bypasses performed during the same period. Seventy-six patients (61%) had suffered from at least one previous myocardial infarction. Forty-five patients (36%) had unstable angina; three-vessel disease was found in 100 cases (80.5%) and a left ventricular ejection fraction lower than 0.4 in 22 (17.7%). There were 18 (14.5%) redo procedures and 90 (72.5%) bilateral internal mammary artery (IMA) grafts. The reasons for using a FIMA were: too short an internal mammary artery pedicle in 83 patients, IMA injury at harvesting in 30 patients and post-bypass ischaemia in areas grafted with pedicled IMA (PIMA) in 11 patients. Cardiopulmonary bypass, moderate hypothermia (30 degrees C) and crystalloid anterograde and retrograde cardioplegia were used in all cases. Sixty-seven FIMA grafts were anastomosed directly to the ascending aorta; 57 were sutured via a saphenous hood using a running suture of polypropylene 7/0 and three were anastomosed end-to-end to a PIMA graft. FIMA grafts were directed to the left anterior descending (34%), the circumflex (37%) and the right coronary artery (29%). In total, 179 anastomoses were constructed using 127 FIMA, 136 using PIMA and 158 using saphenous veins (3.8 anastomoses per patient). Hospital mortality and postoperative myocardial infarction rates were 5.6% (seven patients) and 3.2% (four patients), respectively. Cardiac-related mortality was 3.2% (four patients); three of these four patients had been operated on for evolving infarction and one underwent a redo procedure. Four of the 117 survivors died later on; in two, it was cardiac-related and a result of global heart failure at 9 and 12 months. Of the 113 remaining patients, 106 are symptom free after a mean follow-up of 28.2 (range 3-84) months. Fifty-nine patients (50.4%) were restudied by angiography at a mean interval of 15 months. Patency rates of FIMA anastomosed either directly to the aorta or via a saphenous hood were 82.8 or 89.7%, respectively. Patency rates of FIMA directed to the left anterior descending, the circumflex and the right coronary artery were 85.7, 88 and 83.3%, respectively. Global FIMA patency was 86.4%, while global PIMA patency was 100%. The FIMA mid-term patency rates compare unfavourably with those of PIMA: FIMA should therefore be restricted to the cases where PIMA or other pedicled arterial grafts are unavailable.
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PMID:Free internal mammary artery graft in myocardial revascularization. 886 40

An important factor in the production of myocardial damage following cardiopulmonary bypass in the creation of oxygen derived free radicals. Few sources for these radicals have been identified but experimentally activated neutrophils are known to release free radical which contribute to myocyte necrosis. The aim of this pilot study was to identify whether, by depleting patients of leukocytes and particularly neutrophils on bypass, a better degree of myocardial protection could be observed using specific identifiers of myocardial damage. Ten patients undergoing urgent coronary artery bypass for unstable angina with impaired left ventricular function were leuko-depleted using a PALL medical leukocyte filter in the extra corporeal circulation together with leukocyte depletion of all transfused blood. A similar group of matched controls had only an arterial line filter without leukodepletion. All patients were operated by one surgeon using identical techniques of intermittent cross clamping and fibrillation at moderate hypothermia. Full blood count, Glutathione, Troponin T and CPK/MB were measured before, during and at identified intervals up to 72 hour after bypass. Preliminary results show little change in the total leukocyte count but the Troponin T and CPK/MB values were lower in the filtered group than in the control group and an increased level of total Glutathione in the filter group showed that there was less oxidated stress on the myocardium. Currently this filter is an expensive addition to bypass surgery but these preliminary results suggest that activated neutrophil depletion on bypass may be of benefit to patients with unstable angina, impending myocardial necrosis and low ejection fraction.
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PMID:Does activated neutrophil depletion on bypass by leukocyte filtration reduce myocardial damage? A preliminary report. 1006 58


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