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Asymptomatic cerebral infarction in patients with chronic atrial fibrillation
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patients undergoing coronary artery bypass grafting. Substances such as acetylcholine, thrombin, and adenosine induce relaxation in the vasculature mediated by a diffusible substance, EDRF. Relaxation is more prominent in arteries than in veins exposed to EDRF. Thus, the internal mammary artery demonstrated an 86% reduction in tension compared to only 25% for the saphenous vein. The weaker response in the saphenous vein may be due to differences in contractile properties, mechanical damage during vein harvesting, or to intrinsic differences in endothelial reactivity. However, although some endothelial damage was present in the veins, extensive removal of the endothelial layer is required to completely prevent relaxation. Reduced endothelial production of EDRF is another possible explanation. However, the reduced response of saphenous veins to EDRF may contribute to their lower patency rates as coronary bypass grafts. More effective release of EDRF in mammary arteries may enhance local regulation of vascular tone and perhaps prevent thrombosis.
Kempster PA, Gerraty RP, Gates PC: Asymptomatic cerebral infarction in patients with chronic atrial fibrillation. Stroke 1 9 : 9 5 5 957, 1988 An increased rate of stroke has been previously noted in patients with chronic atrial fibrillation. This retrospective study suggests that asymptomatic cerebral infarction is more common in patients with atrial fibrillation than in a control population. Seven patients out of 54 with atrial fibrillation had CT scan evidence of previous silent cerebral infarction, as compared with 7 of 168 prospectively studied patients presenting with symptoms of cerebral isehemia. Although the data confirm previous studies, methodologic problems related to patient selection in the retrospective analysis are present.
Lazor L, Russell JC, DaSilva J, et al: Use of the multiple-uptake gated acquisition scan for the preoperative assessment of cardiac risk. Surg Gynecol Obstet 167:234-238, 1988 This retrospective study of 196 patients correlated the ejection fraction by multiple-uptake gated acquisition scan
CAROL L. LAKE
(MUGA), a radionuclide angiogram, with cardiac-related mortality after subsequent cardiac or noncardiac surgery. With arbitrary divisions into three groups by ejection fraction (group 1 >_-0.55, group 2 0.36 to 0.54, and group 3 <0.35), cardiac mortality was 2.2%, 5.4%, and 19.5%, respectively. The predictive value of MUGA scans by type of surgical treatment demonstrated a statistically significant difference among the groups for noncardiac, but not cardiac, procedures. In noncardiac procedures, the mortality was 0% in group 1, 3.3% in group 2, and 33.3% in group 3. Mortality was also correlated with ventricular function as monitored by pulmonary capillary wedge pressure (PCWP); patients with PCWP >20 had a 55.6% mortality. The ASA physical status also correlated with mortality with 16.3% of ASA 4 patients dying of cardiac causes compared with 2.2% of ASA 3 patients ( P = 0.005). Duration of operation, age, and findings on two-dimensional echocardiogram failed to correlate with mortality. MUGA scans effectively assess ventricular function, permitting intensive monitoring and therapy in the perioperative period. ACKNOWLEDGMENT
The papers reviewed in this issue were published in the following journals: Acta Anaesthesiologica Scandinavica,
Annals of Internal Medicine, American Heart Journal, American Journal of Cardiology, American Journal of Physiology, American Journal of Surgery, American Review of Respiratory Disease, Anaesthesia, Anesthesia and Analgesia, Anesthesiology, Annals of Internal Medicine, Annals of Surgery, Annals of Thoracic Surgery, Arteriosclerosis, Basic Research in Cardiology, British Journal of Anaesthesia, Chest, Circulation, Clinical Pharmacology and Therapeutics, Critical Care Medicine, Anaesthesist, European Heart Journal, International Journal of Cardiology, Journal of the American College of Cardiology, Journal of the American Medical Association, Journal of Applied Physiology, Journal of Pharmacology and Applied Therapeutics, Journal of Thoracic and Cardiovascular Surgery, Journal of Trauma, Journal of Ultrasound Medicine, New England Journal of Medicine, Pace, Stroke, Surgery, Gynecology and Obstetrics, Thorax, Transfusion, Transplantation, and Vascular Surgery.
patients undergoing coronary artery bypass grafting. Substances such as acetylcholine, thrombin, and adenosine induce relaxation in the vasculature mediated by a diffusible substance, EDRF. Relaxation is more prominent in arteries than in veins exposed to EDRF. Thus, the internal mammary artery demonstrated an 86% reduction in tension compared to only 25% for the saphenous vein. The weaker response in the saphenous vein may be due to differences in contractile properties, mechanical damage during vein harvesting, or to intrinsic differences in endothelial reactivity. However, although some endothelial damage was present in the veins, extensive removal of the endothelial layer is required to completely prevent relaxation. Reduced endothelial production of EDRF is another possible explanation. However, the reduced response of saphenous veins to EDRF may contribute to their lower patency rates as coronary bypass grafts. More effective release of EDRF in mammary arteries may enhance local regulation of vascular tone and perhaps prevent thrombosis.
Kempster PA, Gerraty RP, Gates PC: Asymptomatic cerebral infarction in patients with chronic atrial fibrillation. Stroke 1 9 : 9 5 5 957, 1988 An increased rate of stroke has been previously noted in patients with chronic atrial fibrillation. This retrospective study suggests that asymptomatic cerebral infarction is more common in patients with atrial fibrillation than in a control population. Seven patients out of 54 with atrial fibrillation had CT scan evidence of previous silent cerebral infarction, as compared with 7 of 168 prospectively studied patients presenting with symptoms of cerebral isehemia. Although the data confirm previous studies, methodologic problems related to patient selection in the retrospective analysis are present.
Lazor L, Russell JC, DaSilva J, et al: Use of the multiple-uptake gated acquisition scan for the preoperative assessment of cardiac risk. Surg Gynecol Obstet 167:234-238, 1988 This retrospective study of 196 patients correlated the ejection fraction by multiple-uptake gated acquisition scan
CAROL L. LAKE
(MUGA), a radionuclide angiogram, with cardiac-related mortality after subsequent cardiac or noncardiac surgery. With arbitrary divisions into three groups by ejection fraction (group 1 >_-0.55, group 2 0.36 to 0.54, and group 3 <0.35), cardiac mortality was 2.2%, 5.4%, and 19.5%, respectively. The predictive value of MUGA scans by type of surgical treatment demonstrated a statistically significant difference among the groups for noncardiac, but not cardiac, procedures. In noncardiac procedures, the mortality was 0% in group 1, 3.3% in group 2, and 33.3% in group 3. Mortality was also correlated with ventricular function as monitored by pulmonary capillary wedge pressure (PCWP); patients with PCWP >20 had a 55.6% mortality. The ASA physical status also correlated with mortality with 16.3% of ASA 4 patients dying of cardiac causes compared with 2.2% of ASA 3 patients ( P = 0.005). Duration of operation, age, and findings on two-dimensional echocardiogram failed to correlate with mortality. MUGA scans effectively assess ventricular function, permitting intensive monitoring and therapy in the perioperative period. ACKNOWLEDGMENT
The papers reviewed in this issue were published in the following journals: Acta Anaesthesiologica Scandinavica,
Annals of Internal Medicine, American Heart Journal, American Journal of Cardiology, American Journal of Physiology, American Journal of Surgery, American Review of Respiratory Disease, Anaesthesia, Anesthesia and Analgesia, Anesthesiology, Annals of Internal Medicine, Annals of Surgery, Annals of Thoracic Surgery, Arteriosclerosis, Basic Research in Cardiology, British Journal of Anaesthesia, Chest, Circulation, Clinical Pharmacology and Therapeutics, Critical Care Medicine, Anaesthesist, European Heart Journal, International Journal of Cardiology, Journal of the American College of Cardiology, Journal of the American Medical Association, Journal of Applied Physiology, Journal of Pharmacology and Applied Therapeutics, Journal of Thoracic and Cardiovascular Surgery, Journal of Trauma, Journal of Ultrasound Medicine, New England Journal of Medicine, Pace, Stroke, Surgery, Gynecology and Obstetrics, Thorax, Transfusion, Transplantation, and Vascular Surgery.