In-vivo measurements of coronary blood flow using 16-slice multidetector spiral computed tomography (MDCT) in a porcine model.

PURPOSE: To determine whether CTCA supplemented with CT flow measurements can be used to demonstrate and semiquantitatively evaluate poststenotic coronary blood flow in a porcine model. MATERIALS AND METHODS: In 10 thoracotomized pigs, transit time flow meter probes were attached to the aorta and left anterior descending artery (LAD) for real-time blood flow volumetry. A vascular silicone occluder was deployed around the LAD proximal to the probe to create medium-grade (MGS) and high-grade stenoses (HGS). The blood flow was measured by CT without vessel occlusion and distal to the stenoses. Time-density curves were generated from CT data. The curves were evaluated by calculating and cross-plotting the variables "slope of the density increase", "peak density" and "slope of the post-peak density decrease" from the LAD and aortic CT data. RESULTS: The flow in the LAD dropped to 41 % +/- 9 % (mean +/- SD) for MGS and 12 % +/- 6 % for HGS of the baseline. Coronary time-density curves plateaued proportional to luminal narrowing. Unimpaired flow could be differentiated statistically significant from poststenotic flow adjacent to MGS and HGS (p < 0.000 and p < 0.002, respectively). Flow adjacent to MGS and HGS was successfully differentiated for "slope of the density increase" and "slope of the post-peak density decrease" (p < 0.003 and p < 0.030, respectively). CONCLUSION: CT measurements allow semiquantitative evaluation of poststenotic coronary blood flow.

The Effect of Thoracic Epidural Lidocaine on Blood Flow of Grafted Coronary Vessels in Coranary Artery Bypass Graft Surgery / 대한마취과학회지

BACKGROUND: Thoracic epidural anesthesia (TEA) is increasingly used to reduce stress response, pain and pulmonary complication of patients under coronary artery bypass graft (CABG). However, effects of TEA on blood flow of grafted coronary artery are scarcely noticed. Imbalance between blood flow of grafted coronary artery and myocardial oxygen demand can bring about perioperative myocardial ischemia. Thus we evaluated the effect of TEA on blood flow of coronary grafts. METHODS: Twenty seven patients with triple-vessel coronary artery disease under CABG were recruited. Left internal mammary artery, radial artery, and great saphenous vein were anastomosed to left anterior descending artery, obtuse marginalis, and posterior descending artery, respectively. Before surgery, an epidural catheter was inserted. Total intravenous anesthesia was undertaken using fentanyl, midazolam and vecuronium. After grafts anastomosis, blood flow of grafted coronary artery was measured using transit-time flowmeter (TTFM) before weaning from CPB. And then, mixture of 2% lidocaine 10 ml, fentanyl 50microgram and bicarbonate 1 mEq was injected via epidural catheter. Under the constant pump flow, the blood flow of grafted coronary artery before, 10 and 20 minutes after drug administration were measured using TTFM. RESULTS: The blood flow of coronary artery grafts was similar in three time interval, irrespective of grafted artery. There are no significant differences in changes in coronary blood flow associated with epidural lidocaine injection among 3 types of grafted artery. CONCLUSIONS: The present study shows that there are no significant effects of TEA on blood flow of newly grafted coronary artery after CABG.

Effects of Korean Red Ginseng on the Vaginal Blood Flow and Structure in Female Castrated Rats / 대한비뇨기과학회지

PURPOSE: Ginseng is a traditional Asian remedy for sexual dysfunction. The purposes of this study were to investigate the effects of Korean red ginseng (KRG) on the vaginal blood flow and tissue structure in female castrated rats. MATERIALS AND METHODS: Female Spague-Dawley rats (200-210gm) were divided into 4 groups: the control (n=20), castration (n=30), and castration plus oral administration of KRG extracts (50 and 100mg/kg/day, n=15 and n=15, respectively). After 1 month of treatment, the serum estrogen and total cholesterol levels were measured. The vaginal blood flow was measured using laser Doppler flowmeter before and after pelvic nerve stimulation (PNS). The vaginal tissue was processed for Masson's trichrome stain, immunohistochemistry and Western blotting. RESULTS: The serum estrogen level was significantly decreased in the castration group (0.8+/-1.9ng/ml); however, it increased up to the control level (2.2+/-1.3ng/ml) in both the KRG administration groups (p<0.05). The PNS-induced vaginal blood flow tended to improve in the KRG treatment groups. On the histology, the vaginal epithelial layer and submucosal microvasculature showed improvement in the KRG treatment groups. The expression of estrogen receptor increased in the KRG treatment groups compared to the castration group. CONCLUSIONS: These results suggested that KRG extracts seem to have an estrogenic effect on castrated female rats. This implies that the KRG extracts may have an ameliorating effect on sexual function in menopausal woman.

Effect of local anesthesia on pulpal blood flow in mechanically stimulated teeth / 대한치과보존학회지

The aims of the study were to evaluate the effect of epinephrine-containing local anesthetics on pulpal blood flow (PBF) and to investigate its effect on cavity preparation-induced PBF change. PBF was recorded using a laser Doppler flowmeter (Perimed Co., Sweden) from canines of nine cats under general anesthesia before and after injection of local anesthetics and after cavity preparation. 2% lidocaine hydrochloride with 1 : 100,000 epinephrine was administered by local infiltration given apical to the mandibular canine at the vestibular area and the same volume of isotonic saline was injected on the contralateral tooth as a control. A round carbide bur was operated at slow speed with isotonic saline flushing to grind spherical cavities with increasing depth through the enamel and into the dentin on both teeth. The obtained data was analyzed with paired t-test. Cavity preparation caused significant increase of PBF (n = 9, p < 0.05). Local infiltration of lidocaine with epinephrine resulted in decreases of PBF (n = 9, p < 0.05), whereas there was no significant change of PBF with the physiologic saline as a control. Cavity preparation on tooth anesthetized with lidocaine with epinephrine caused significantly less increase of PBF than in control tooth (p < 0.05). Therefore, the result of the present study demonstrates that local infiltration of 2% lidocaine with 1 : 100,000 epinephrine effectively reduces PBF increase caused by cavity preparation.

Effect of Korean Red Ginseng on Vaginal Blood Flow and Structure in Hypercholesterolemic Female Rats / 대한남성과학회지

PURPOSE: The aims of this study were to investigate the effects of Korean Red Ginseng(KRG) on vaginal blood flow and histological changes in a hypercholesterolemic female rat model. MATERIALS AND METHODS: Female Sprague-Dawley rats were divided into two groups: the control(n=20) and the hypercholesterolemia(n=40). Hypercholesterolemia group was fed a high fat diet(2% cholesterol, 1% cholic acid, 5% coconut oil) for 12 weeks. The hypercholesterolemia group was further divided into the vehicle only and the KRG treatment(50 mg/kg/day) groups. After 4 and 8 weeks of treatment, vaginal blood flow was measured by a laser Doppler flowmeter. Vaginal tissues were processed for histology and Western blot. RESULTS: After 4 and 8 weeks of treatment, serum cholesterol levels(mg/dl) were significantly increased in the hypercholesterolemia group(1185.0+/-736.1, 934.3+/-212.3) compared with the control group(69.7+/-19.5, 67.1+/-7.2), and partially decreased in KRG treatment group(688.2+/-251.5, 694.2+/-150.4), respectively. Vaginal blood flow(ml/min/100 g tissue) after pelvic nerve stimulation was lower in the hypercholesterolemia group(17.3+/-7.9, 17.9+/-5.5) compared with the control group(27.3+/-17.1, 26.9+/-16.4), however, the KRG treatment group(29.5+/-10.3, 27.4+/-11.1) was as high as the control group, respectively. The expressions of TGF-beta1 tended to increase in the vagina of the hypercholesterolemia animals compared to those of the control and the KRG treatment groups. CONCLUSIONS: KRG treatment in hypercholesterolemic female rats decreased serum cholesterol levels and improved vaginal blood flow. These results suggest that KRG treatment may have a beneficial effect in women's sexual health.

The Effect of Smoking on blood Flwo of Optic nerve Head

Disorder of optic nerve blood perfusion has been thought to be one of risk factors for galucoma, and smoking has been suggested to affect optic nerve blood flow. Recently the scanning laser Doppler flowmetry (SLDF) was introduced and Heidelberg Retina flowmeter (RF), a kind of SLDF was reported to be useful to measure the capillary blood flow of optic nerve head and retina. The purpose of this study was to evaluated the variability of measurements in the optic nerve head and preipapillry retinal blood flow using HRF and to investigate the effect of smoking on optic nerve head and peripapillary retinal blood flow using HRF. Five eyes of five young healthy volunteers were enrolled to evaluate variability. Five scans were obtained in each eye. The mean coefficient of variation except disc cupping area was 19%. Baseline measurements of blood pressure, pule rate and perfusion image using HRF were obtained in 10 eyes of 10 healthy habitual smokers and then asked to smoke a cigarette. Measurements were then repeated 10 minutes and 1 hours after smoking. A significant increased in heart rate and systolic and diastolic blood pressure was demonstrated 10 minutes after smoking. The blood flow parameters Volume, Flow, Velocity of optic nerve head and peripapillary retina were reduced 10 minutes after smoking, but no significance was demonstrated. This study shows that the effect of smoking is not significant on blood flow of optic nerve head and peripapillary retina. This result may be caused from the authoregulation of optic nerve head of young subjects of third and fourth decades. To investigate the effect of autoregluation on smoking, further evaluation on subjects with different autoregulation such as glaucoma patients will be needed.

Effects of Nicardipine and Sodium Nitroprusside on Functional Recovery of Stunned Myocardium in Dogs / 대한마취과학회지

BACKGROUND: Cytosolic Ca2+ overload and oxygen derived free radicals may contribute to stunned myocardium. The pnt study was aimed to investigate the effects of nicardipine and sodium nitroprusside (SNP) on the functional recovery of postischemic reperfused myocardium. METHODS: Fifty-seven halothane-anesthetized dogs were subjected to 15 minutes of 1eft anterior descending coronary artery (LAD) occlusion and 3 hours of reperfusion. They were randomly assigned to receive either intracoronary nicardipine (n=11) or SNP (n=10) alone or both (nicardipine plus SNP, n=10). Eleven dogs that received saline i.c. served as the controL Regional myocardial contractility was evaluated by systolic shortening (%SS), the preload recruitable stroke work slope (Mw), and intramyocardial pressure (IMPs). Diastolic function was assessed by time constant of myocardial relaxation (IMP-tau) and postsystolic shortening (%PSS), LAD blood flow was measured by a Doppler flowmeter as well. RESULTS: LAD occlusion produced a significant reduction in systolic as well as diasto1ic functions to similar degrees in all groups. However, %SS was significantly higher in the nicardipine, SNP and nicardipine-SNP groups (67%, 56%, and 68% of baseline values, respectively) than in the controls (20%) at 3 hours of reperfusion. Furthermore, Mw recovered to the baseline with the onset of reperfusian in the three experimental groups. IMP-tau was restored to the baseline during early nperfusion in the SNP-treated groups but was significantly prolonged in the control and nicardipine poups throughout the seperfusion. LAD blood flow during reperfusion was higher in the SNP-treated groups in comparison to the control group. CONCLUSIONS: Treatment with either nicardipine or SNP enhances the recovery of mgional contractile function in the canine model of myocardial stunning. SNP not nicardipine is also beneficial in attenuation of early diastolic dysfunction. Nicardipine combined with SNP improved systolic as well as early diastolic functions more significantly when compared to either nicardipine or SNP alane.

Effect of Intracoronary Nicardipine on Functional Recovery of Stunned Myocardium in Halothane-Anesthetized Dogs / 대한마취과학회지

BACKGROUND: Myocardial calcium overload during reperfusion may contribute to myocardial stunning. The protective effect of nicardipine against post-ischemic myocardial dysfunction was investigated. METHODS: Twenty-two halothane-anesthetized dogs were subjected to 15 minutes of left anterior descending coronary artery (LAD) occlusion and subsequent 3 hour reperfusion. One group of dogs (n=11) received nicardipine (1 microgram/kg/min) and another group (n=11) received saline (0.5 ml/kg/h) through intracoronary catheter for 1 hour beginning 15 minutes before LAD occlusion. Systolic shortening (%SS) and preload recruitable stroke work slope (Mw), as an index of regional myocardial contractility, and IMP-tau (time constant of myocardial relaxation based on intramyocardial pressure (IMP)) and post-systolic shortening (%PSS), as an index of regional diastolic function, were evaluated. LAD blood flow was measured by Doppler flowmeters as well. RESULTS: Regional systolic as well as diastolic functions during acute myocardial ischemia were similar between the two groups. However, Mw recovered to the baseline value with the onset of reperfusion in the nicardipine group but was significantly decreased throughout the reperfusion period in the controls. After 3 hours of reperfusion, the nicardipine group had recovered 67% of %SS, compared with 20% of the control group. IMP-tau was restored to the baseline value by 60 min of reperfusion in the control group but was significantly prolonged in the nicardipine group throughout the reperfusion period. CONCLUSIONS: Intracoronary nicardipine enhances the recovery of regional contractile function but prolongs myocardial relaxation in the canine model of myocardial stunning.