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STUDY OBJECTIVE To define the behavior of power spectral heart rate variability (PSHR) during potentially stressful events in the perioperative period, and relate it to changes in blood pressure (BP) and heart rate (HR). DESIGN Longitudinal clinical study. SETTING Operating room and recovery suites of a large tertiary care referral center. PATIENTS 26(More)
In this study we examined the hypothesis that endothelial damage increases proximal coronary arterial vasomotor tone and sensitivity to vasoconstrictor stimulation. The response of the left anterior descending coronary artery (LAD) (% area change) to serotonin and nitroglycerin were examined in eight anesthetized (Innovar + nitrous oxide), closed-chest dogs(More)
In the nonfailing heart, normovolemic hemodilution increases cardiac output and decreases total peripheral resistance (TPR). Putative mechanisms mediating the decrease in TPR include reflex vasodilation and changes in the local regulation of blood flow. Our objectives were to determine whether ablation of reflex neural mechanisms or the inhibition of nitric(More)
Twenty-four mongrel dogs, weighing 13 to 24 kg, were used to study the effectiveness of anastomosis by Argon Laser beam. After anesthesia, intubation and controlled ventilation, they were submitted to three types of vascular anastomoses: saphenous vein intercarotid artery bypass; left mammary artery/left anterior descending coronary artery bypass; and(More)
The "antimuscarinic effect" of fentanyl and its dependence on subtypes of receptors were characterized in isolated porcine coronary arteries. Left anterior descending coronary arteries were dissected from the hearts of 60 adult pigs obtained at a slaughterhouse and prepared for isometric tension studies. The effects of fentanyl on the cumulative(More)
Myocardial ischemia during surgery can be caused by coronary vasospasm. Neurohumoral mechanisms are involved in this phenomenon, and various substances have been suggested as possible causes, including acetylcholine, histamine, and norepinephrine. The responses of isolated porcine coronary arteries (from 117 pig hearts) with (E+) and without (E-)(More)
Our overall goal was to investigate the mechanism by which fentanyl attenuates acetylcholine-induced contraction in porcine coronary artery. We tested the hypothesis that fentanyl attenuates muscarinic coronary contraction via sigma receptor activation. Left coronary artery vascular rings were isolated from porcine hearts and were suspended in organ(More)
Exercise is associated with release of catecholamines and vasoactive intestinal polypeptides. Recurrent exposure to catecholamines modifies the sensitivity of adrenoceptors. To test the hypothesis that exercise training may affect the sensitivity of the epicardial coronary arteries, we performed studies on isolated coronary arteries from male dogs capable(More)
Substance P (SP), a vasoactive neuropeptide detected in animal and human hearts has been reported to increase coronary blood flow in animals. However, no data are available on SP effects on epicardial coronary arteries, the site of coronary disease. To determine the amount and distribution of SP and its action in the large coronary vessels, we studied two(More)
Vasoactive intestinal polypeptide, a neurotransmitter peptide detected in animal and human hearts, has been found in nerves of coronary arteries. To determine the amount and distribution of vasoactive intestinal polypeptide in the large coronary vessels and its possible participation in coronary vasoregulation, two groups of animals were studied. In the(More)