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ABSTRACT: Vessel lumens that have been chronically narrowed by atherosclerosis should be increased in flow velocity and intrastenotic area pressure to maintain an equal flow. This might be followed by a decrease in hemodynamic energy, leading to a reduction of tissue perfusion. In this study, we compared hemodynamic energies according to degrees of stenotic vasculature between pulsatile flow and nonpulsatile flow. Cannuale with 25, 50, and 75% diameter stenosis (DS) were located at the outlet cannula. Using the Korea Hybrid ventricular assist device (KH-VAD) (pulsatile pump: group A) and Biopump (nonpulsatile pump: group B), constant flow of 2 L/min was maintained then real-time flow and velocity in the proximal and distal part of the stenotic cannula were measured. The hemodynamic energies of two groups were compared. At 75% DS, proximal energy equivalent pressure (EEP) delivered to the distal end was only 41.9% (group A) and 42.5% (group B). As the percent EEP fell below 10%, pulsatility disappeared from the 50% stenosis in group A. The surplus hemodynamic energy (SHE) of group B at all degrees of stenosis must have been 0, which was also the case of group A at 75% stenosis. This research evaluated the hemodynamic energy on various degrees of DS in both pulsatile and nonpulsatile flow with mock system. Using a pulsatile pump, pulsatility disappeared above 50% DS while hemodynamic energy was maintained. Therefore, our results suggest that pulsatile flow has a better effect than nonpulsatile flow in reserving hemodynamic energy after stenotic lesion.
Artificial Organs 11/2011; 35(11):1118-23. · 2.00 Impact Factor
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ABSTRACT: Blood viscosity during operation of ventricular assist device (VAD) can be changed by various conditions such as anemia. It is known generally that the blood viscosity can affect vascular resistance and lead to change of blood flow. In this study, the effect of fluid viscosity variation on hemodynamic energy was evaluated with a pulsatile blood pump in a mock system. Six solutions were used for experiments, which were composed of water and glycerin and had different viscosities of 2, 2.5, 3, 3.5, 4, and 4.5 cP. The hemodynamic energy at the outlet cannula was measured. Experimental results showed that mean pressure was increased in accordance with the viscosity increase. When the viscosity increased, the mean pressure was also increased. However, the flow was decreased according to the viscosity increase. Energy equivalent pressure value was increased according to the viscosity-induced pressure rise; however, surplus hemodynamic energy value did not show any apparent changing trend. The hemodynamic energy made by the pulsatile VAD was affected by the viscosity of the circulating fluid.
Artificial Organs 09/2011; 35(11):1123-6. · 2.00 Impact Factor
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Pathology International 07/2011; 61(7):445-8. · 1.62 Impact Factor
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European Heart Journal 12/2009; 31(8):1006. · 10.48 Impact Factor
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ABSTRACT: A 29-year-old female patient in the 28th week of pregnancy was diagnosed with a cardiac tumor. We performed tumor excision and mitral valve replacement, and her baby was born successfully with cesarean section on the 9th day after cardiac surgery. After this event, 8 cycles of chemotherapy were administered. After 10 months, metastatic intimal sarcoma of the right ovary developed, and a right salpingo-oophorectomy and omentectomy was performed. However, the patient died of sudden onset of intractable ventricular fibrillation.
Asian cardiovascular & thoracic annals 02/2007; 15(1):66-8.
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Kyung Sun,
Ho Sung Son, Jae Seung Jung,
Bong Kyu Cheong,
Jae Seung Shin,
Kwang Taik Kim,
Hye Won Lee,
Sang Su Ahn,
Sung Young Park,
Hye Jung Oh,
Hwan Sung Lee,
Eun Bo Shim,
Yang Rae Rho,
Hyuk Soo Lee,
Byoung Goo Min,
Hyoung Mook Kim
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ABSTRACT: A Korean artificial heart (AnyHeart) has been implanted in 29 various animals (52-470 kg) to evaluate hemodynamic performance and electromechanical stability. Most were implantable biventricular assist devices in use. A right thoracotomy approach has been a standard technique of implantation. A preclinical fitting test was also performed to observe anatomical feasibility and to compare surgical techniques in 10 human cadavers. The first case of human application was made as a lifesaving procedure on June 12, 2001.
Artificial Organs 02/2003; 27(1):8-13. · 2.00 Impact Factor
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ABSTRACT: How much flow is required by a nonpulsatile pump to match the coronary blood flow equivalent to that of pulsatile pump? A cardiopulmonary bypass circuit from the right atrium to the ascending aorta was constructed in a ventricular fibrillation model using 13 Yorkshire swine. The animals were randomly divided into two groups: CONTROL (pulsatile T-PLS, n = 7) or EXPERIMENTAL (nonpulsatile Biopump, n = 6). The hemodynamic data at mid-LAD level was measured with a flow meter at baseline and every 20 minutes after pump flow initiation. The pump flow was started from 2 L/min in both groups (67 +/- 8 in CONTROL and 70 +/- 9 ml/kg/min in EXPERIMENTAL; p = NS), and the pump flow of the EXPERIMENTAL group was increased to match the coronary flow of the CONTROL group. To maintain mean velocity and flow in the LAD, the EXPERIMENTAL group required significantly higher pump flow at 20, 40, and 60 minutes (84 +/- 17 vs. 67 +/- 8, 87 +/- 24 vs. 67 +/- 8, 85 +/- 18 vs. 67 +/- 8 ml/kg/min, respectively, p < 0.05). The LAD diameter was substantially smaller in the CONTROL group and the resistance index was significantly lower in the CONTROL group at 80 minutes and 120 minutes after bypass (0.56 +/- 0.26 vs. 0.87 +/- 0.20 and 0.61 +/- 0.23 vs. 0.90 +/- 0.06; p < 0.05). In conclusion, we found that the nonpulsatile pump may require 25%-28% higher pump flow than the pulsatile pump to maintain equivalent coronary blood flow.
ASAIO journal (American Society for Artificial Internal Organs: 1992) 53(6):785-90. · 1.39 Impact Factor
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ABSTRACT: Extra hemodynamic energy is one of the major benefits of pulsatile flow, improving blood flow to vital organs. But most (80%) of the hemodynamic energy generated from pulsatile flow is damped by the extracorporeal circuit. Most models devised to minimize hemodynamic energy loss have been in vitro pediatric models. The purpose of this study was to measure hemodynamic energy in different vessels of different organs with an in vivo adult swine model. An extracorporeal circuit was constructed for seven Yorkshire swine using a pulsatile pump (Twin-Pulse Life Support). The mean arterial pressure (MAP), energy equivalent pressure (EEP), and surplus hemodynamic energy (SHE) at the renal artery, carotid artery, aortic cannula site, and postoxygenator site were measured simultaneously before starting the pump and at the pump rates of 25, 35, and 45 bpm. The MAP of the renal or carotid artery was 40.0%-51.2% of the postoxygenator site. The EEP and SHE of both arteries were 11.6%-13.0% and 5.5%-7.4% of the postoxygenator site, respectively. The MAP and EEP of both arteries after starting the pump were lower than at baseline. The SHE of the renal artery after starting the pump was significantly higher than at baseline. The SHE of the carotid artery increased substantially after starting the pump although not statistically significantly. There was a significant hemodynamic energy loss in both arterial sites compared with the postoxygenator site. Also, a difference in hemodynamic energy loss was observed in vessel-to-vessel or vessel-to-circuit site comparison. This difference creates a bias in studying pulsatility and its effects. Therefore, the measurement method of hemodynamic energy must be standardized and the measurement site clarified to yield accurate study results.
ASAIO journal (American Society for Artificial Internal Organs: 1992) 56(5):397-402. · 1.39 Impact Factor
