• Title/Summary/Keyword: Cardiovascular flow

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Influence of Phenylephrine and Clonidine on The Coronary Flow in Rats (백서 관상 혈류에 미치는 Phenylephrine 및 Clonidine 의 영향)

  • 김광호
    • Journal of Chest Surgery
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    • v.23 no.6
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    • pp.1107-1117
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    • 1990
  • The regulatory role of the post \ulcorner1-and \ulcorner2-adrenoceptors on cardiac function, particularly in coronary flow rate, was investigated in the isolated rat heart treated with 10-6 M propranolol. When introduced into the left atrium of the heart, phenylephrine[10-7-10-2 M] decreased coronary flow rate and increased mean coronary resistance in a dose related fashion, but did not affect heart rate. Methoxamine also elicited the increment of coronary resistance and the decrement of coronary flow rate, though the effects of methoxamine were weaker than those by phenylephrine. The effect of phenylephrine was inhibited by 1\ulcornerM prazosin and shifting the dose-response curve to the right. The effects of clonidine, a selective \ulcorner2-adrenoceptor agonist, were studied in the heart taken from reserpinized rats. Clonidine increased coronary resistance, decreased heart rate and coronary flow rate with a dose-dependent manner. These effects were abolished by 10-6 M yohimbine, a selective \ulcorner2-antagonist, and were not affected by 10-6M prazosin. Clonidine also decreased coronary flow and increased mean coronary resistance in electric paced heart. These effects were inhibited by rawoulscine, a selective ca-antagonist. These results indicate that the stimulation of both post \ulcorner1-and \ulcorner2-adrenoceptor causes coronary vasoconstiction. And it is inferred that this model of sympathomimetics-induced coronary vasospasm may provide a useful tool for investigating spasmolytic agents which are of benefit in the treatment of variant angina.

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Development of Solenoid RF coil for 4.7 T Magnetic Resonance Velocimeter to Improve Resolution (해상도 향상을 위한 4.7 T 자기공명유속계 용 솔레노이드 RF 코일 개발)

  • Yang, Byungkuen;Cho, Jee-Hyun;Song, Simon
    • Journal of the Korean Society of Visualization
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    • v.14 no.2
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    • pp.40-45
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    • 2016
  • Magnetic resonance velocimeter (MRV) is a powerful tool to non-invasively measure the velocity of a fluid flow in various fields ranging from medicine to engineering. However, since the demands for accurate measurement in the solid/liquid interface for cardiovascular diseases and porous media increase, the improvement of spatial resolution is required. In this study, a solenoid RF coil is developed for high spatial resolution measurement. The signal-to-noise ratio in solenoid RF coil is increased seventeen times better than that in commercial coil. Moreover, the velocity distribution of Hagen-Poiseuille flow is measured with in-plane resolution of $36{\mu}m$ by $36{\mu}m$ and the accuracy of the measured velocity is compared with theoretical distribution of the laminar flow. Flow rate calculated by MRV is estimated with the flow rate injected by syringe pump.

Myocardial Protection of Contractile Function After Global Ischemia by Compound K in the Isolated Heart

  • Kim, Jong-Hoon
    • Journal of Ginseng Research
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    • v.33 no.4
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    • pp.268-277
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    • 2009
  • Ginsenosides are among the most well-known traditional herbal medicines frequently used for the treatment of cardiovascular symptoms in South Korea. The anti-ischemic effects of compound K (CK), a metabolite of ginsenoside Rb1, on ischemia-induced isolated rat hearts were investigated through the analyses of the changes in the hemodynamics (blood pressure, aortic flow, coronary flow, and cardiac output) and the measurement of the infarct region. The subjects in this study were divided into four groups: the normal control, the CK-alone group, the ischemia-induced group without any treatment, and the ischemia-induced group treated with CK. No significant differences in perfusion pressure, aortic flow, coronary flow, and cardiac output were found between the groups before ischemia was induced. The oxygen and buffer supply was stopped for 30 min to induce ischemia 60 min after reperfusion in the isolated rat hearts, and the CK was administered 5 min before ischemia induction. The CK treatment significantly prevented decreases in perfusion pressure, aortic flow, coronary flow, and cardiac output under ischemic conditions. In addition, the hemodynamics (except for the heart rate) of the group treated with CK significantly recovered 60 min after reperfusion, unlike in the control group. CK significantly limited the infarct. These results suggest that CK treatment has distinct anti-ischemic effects in an exvivo model of an ischemia-reperfusion-induced rat heart.

Anti-ischemic Effect of Polygala Tenuifolia in Isolated Rat Heart

  • Kang, Chang-Won;Kim, Jong-Hoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.11 no.3
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    • pp.89-95
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    • 2007
  • Polygala tenuifolia (PT) is one of the most well-known traditional herbal medicines in Korea which is commonly used for the treatment of cardiovascular symptoms. The anti-ischemic effects of PT in isolated rat heart was investigated by analyzing changes in blood pressure, aortic flow, coronary flow, and cardiac output. And, its underlying mechanism was examined by quantitating intracellular calcium content in rat neonatal cardiomyocytes. Rats were divided into two groups: an ischemia-induced group without any treatment, and an ischemia-induced group treated with PT. Ischemia of isolated heart was induced by stopping the supply of oxygen and buffer for 10 min. The isolated heart was exposed to PT for the first 5 min of 10 min ischemia. PT treatment significantly prevented the decreases of perfusion pressure, aortic flow, coronary flow, and cardiac output under ischemic conditions. In addition, hemodynamics (except heart rate) of the PT-treated group was significantly recovered 60 min after reperfusion compared to the control group (systolic aortic pressure: 83.3% vs. 64.9%, aortic flow volume: 69.5% vs. 48.7%, coronary flow volume: 77.7% vs. 58.4%, and cardiac output: 71.6% vs. 51.2%, p < 0.01). As for the underlying mechanism, PT significantly prevented intracellular calcium increase which was induced by isoproterenol (p < 0.01), suggesting that the anti-ischemic effect of PT is mediated by inhibition of intracellular calcium increase.

Local blood flow in acute respiratory and metabolic acid-base distrubances in dog (급성산-염기 균형장해때의 국소 혈류량 변화)

  • Kim, Sam-Hyeon;Lee, Yeong-Gyun;Kim, U-Gyeom
    • Journal of Chest Surgery
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    • v.17 no.1
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    • pp.101-109
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    • 1984
  • The influences of acute respiratory and metabolic acid-base disturbances on the carotid, renal and coronary blood flow were measured in dogs. Respiratory acidosis was induced by artificial respiration with 8% CO2 -02 gas mixture and respiratory alkalosis was induced by hyperventilation under the control of respirator. Metabolic acidosis and metabolic alkalosis were induced by intravenous infusion of 0.3N hydrochloric acid and 0.6M sodium bicarbonate solution. To observe the effect of hyperkalemia, isotonic potassium chloride solution was infused. CVI electromagnetic flowmeter probes were placed on the left common carotid artery, left renal artery and left circumflex coronary artery. Each flow was recorded on polygraph. 1. The carotid blood flow showed rapid showed rapid and marked increase in acute respiratory acidosis. Even in the cases when arterial blood pressure was lowered during the state of respiratory acidosis, carotid blood flow increased. By the infusion of hydrochloric acid, carotid blood flow increased slowly and returned to the previous label after discontinuation of the infusion. Carotid blood flow also increased by the infusion of large amount of sodium bicarbonate, but it might be the combined effect of expansion of extracellular fluid and compensatory elevation of carbon dioxide tension. 2.The renal blood flow remained unchanged during the acute acid-base disturbances, suggesting effective autoregulation. Renal blood flow, however, increased very slowly when the infusion of potassium chloride continued for a long period. 3.Although less marked than the carotid blood flow, the coronary blood flow increased in the acute respiratory and metabolic acidosis. In asphyxiated condition, coronary blood flow increased most markedly and this might be the combined effect of hypoxia, hypercapnea, and lowering of pH. In summary, the carotid blowflow showed more marked change in the acute respiratory and metabolic acidosis than the renal and coronary blood flow. Respiratory and metabolic components of acid-base disturbances may influence the local blood flow concomitantly, there being more differences in the individual responses, but respiratory component manifested more rapid and marked effect than metabolic component.

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Effects of the Fractionation of Sophorae Radix Water Extract on the Langendorff hearts (고삼 유기용매 분획층이 적출 심장에 미치는 영향)

  • Kim Sang Beam;Kwon Kang Beam;Park Jun Su;Park Gwan Ha;Ryu Do Gon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.1
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    • pp.160-164
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    • 2002
  • The water extract of Sophorae radix was tested for its preventive effects against cardiovascular anaphylaxis elicited in experimental animals. H₂O and ethyl acetate fractionation of Sophorae radix water extract improved anaphylactic cardiac dysfunction in passively sensitized isolated guinea hearts: improvement was noted in the maximal contractile force, post-challenge contractile force, post-challenge coronary flow and creatine kinase change elevation. These results suggest that H₂O and ethyl acute fractionation of Sophorae radix water extract possesses anti-anaphylactic effect in cardiovascular system.

Two Cases of Insomnia in Stroke Patients, Treated with Enhanced Blood Circulation (활혈거어법(活血祛瘀法)으로 호전된 중풍환자(中風患者)의 불면(不眠) 2례)

  • Chung, Ki-Hyun;Kim, Young-Suk;Kang, Kyung-Suk
    • The Journal of Internal Korean Medicine
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    • v.23 no.2
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    • pp.313-320
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    • 2002
  • Insomnia is defined as an experience of inadequate or poor-quality sleeping habit, coupled with more than one of the following symptoms : having difficulty sleeping, waking up too early in the morning or not having sound sleep. Insomnia is one of the most common complications that stroke patients experience, which interfere the patients' recovery. The authors observed two improved cases of insomnia in stroke patients by administrating traditional Korean medicine. The patients suffered from insomnia with nocturnal irritation, constipation, petechia of the tongue, thready or weak pulse. These symptoms, were diagnosed as blood stasis and we administered Hyulboochucke-tang three times a day, to improve blood circulation to remove blood stasis. After the administration, nocturnal irritation disappeared and the insomnia improved. Based on this experience, it is considered that enhancing blood circulation to remove blood stasis can be applied to the treatment of insomnia that stroke patients suffer.

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The Effect of Saphenous Vein Ablation on Combined Segmental Popliteal Vein Reflux

  • Hong, Ki-Pyo;Kim, Do-Kyun
    • Journal of Chest Surgery
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    • v.51 no.5
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    • pp.338-343
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    • 2018
  • Background: This study examined the role of superficial vein surgery in patients with combined superficial venous reflux and segmental popliteal vein reflux. Methods: We retrospectively reviewed 42 limbs in 38 patients with combined superficial venous reflux and segmental popliteal vein reflux who underwent saphenous vein ablation between January 2014 and February 2017. Patients underwent outpatient follow-up duplex ultrasonography at 3, 6, and 12 months postoperatively. Resolution of deep vein reflux was defined as reversed blood flow in a popliteal segment for less than 1.0 second and a decrease in the reflux time of more than 20% of the preoperative reflux time. Results: The mean follow-up period was 9 months (range, 3-23 months). Saphenous vein ablations were performed by stripping in 24 limbs and radiofrequency ablation in 18 limbs. Preoperative segmental popliteal vein reflux resolved in 21 of the 42 limbs (50%). Conclusion: This study demonstrated that superficial venous surgery corrected segmental popliteal vein reflux in 50% of limbs with combined superficial venous reflux and segmental popliteal vein reflux. Other prospective studies are necessary to elucidate the etiology of the non-reversible cases.

Deep Vein as a Graft Conduit (도관으로 사용된 심부정맥)

  • Yie, Kil-Soo;Cheon, Sung-Bin;Oh, Won-Sub;Ryu, Se-Min;Lee, Bong-Ki;Kim, Hyung-Rae;Kim, Keun-Woo
    • Journal of Chest Surgery
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    • v.43 no.4
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    • pp.441-446
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    • 2010
  • The ideal graft requires acceptable size, less tissue toxicity, resistance to infection, and long-term durability. Great saphenous veins are gaining popularity as acceptable graft conduits, but they require time to grow in caliber. We report 2 cases of graft bypass and reconstruction using superficial femoral veins to acheive immediate high-flow patency.

What Is Normal for an Aging Heart?: A Prospective CMR Cohort Study

  • Johannes Kersten;Carsten Hackenbroch;Muriel Bouly;Benoit Tyl;Peter Bernhardt
    • Journal of Cardiovascular Imaging
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    • v.30 no.3
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    • pp.202-211
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    • 2022
  • BACKGROUND: This study aims to investigate normal changes throughout aging of the heart in cardiac magnetic resonance (CMR) imaging in healthy volunteers. While type 2 diabetes mellitus is a frequent finding in the elderly population, also the influence of this circumstance in otherwise healthy persons is part of our study. METHODS: In this prospective single-center trial, 75 healthy subjects in distinct age groups and 10 otherwise healthy diabetics were enrolled. All subjects underwent functional, flow sensitive, native T2- and T1-mapping in a 1.5T CMR scanner. RESULTS: No differences in right and left ventricular ejection fractions were observed between aging healthy groups. Bi-ventricular volumes lowered significantly (p<0.001) between the age groups. There was also a significant decrease in myocardial T1 values, aortic distensibility, and left ventricular peak diastolic strain rates. There were no differences in T2 mapping and the other deformation parameters. Patients with type 2 diabetes mellitus had lower end-diastolic volume indexes; all the other measurements were comparable. CONCLUSIONS: Aging processes in the healthy heart involve a decrease in ventricular volumes, with ejection fractions remaining normal. Stiffening of the myocardium and aorta and a decrease in T1 values are potential indications of age-related remodeling. Type 2 diabetes mellitus seems to have no major influence on aging processes of the heart.