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[in Japanese]
1988 Volume 17 Issue 3 Pages
817
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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- New control method using back electromotive force-
T. NAKAMURA, K. HAYASHI, J. SEKI
1988 Volume 17 Issue 3 Pages
819-822
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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A control method using the back electromotive force generated in the motor windings of the 3-phase brushless do motor has been developed for an implantable cardiac assist device. The pulse-width modulation with the fixed duty ratio and variable voltage is useful for this control method. Two of the 3 nodes of the motor are driven by the squared wave voltage signals having the same amplitude and opposite phases, and the remaining node is used to detect the phase information of the back electromotive force signal. This method is applied when the the motor speed is high, while the open-loop control method is used for the low speed.
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S. FUKUNAGA, Y. HAMANAKA, H. ISHIHARA, T. SUEDA, K. KANEHIRO, T. MATSU ...
1988 Volume 17 Issue 3 Pages
823-826
Published: June 15, 1988
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An implantable artificial heart was made using br ushless DC motor and cylindrical cam with Harmonic Drive as reduction gear. A specially designed cylindrical cam makes one-directional revolution into reciprocation without reversing the motor, then two sacs inside the driver are pushed alternately by the pusher-plates located at both ends of the cam. Two sacs, the blood chambers, are made of polyurethane rubber, with design stroke volume of 87mL. The artificial heart worked at the driving rate of 39-125bpm along with the flow rate of 2.9-7.3L/min on mock circulatory system, consuming 15-43W of electric power. Temperature increase at the surface of the artificial heart was 3.9 °C, while that of saline water in the mock system was 0.4°C. Then animal experiment was carried out using a calf, and coming problems of this artificial heart were clarified.
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S. TAKATANI, H. TAKANO, Y. TAENAKA, H. NODA, M. KINOSHITA, M. UMEZU, T ...
1988 Volume 17 Issue 3 Pages
827-830
Published: June 15, 1988
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Development and improvement of a left-right simultaneously ejecting motor driven TAH system. In this study, efforts have been expended to miniaturize and stabilize the motor-driven TAH system that was proposed previously. A low speed and high torque DC brushless motor was developed and mechanical system was redesign to reduce the overall TAH weight to about 850gm. The control system was improved by incorporation of EPROM so that velocity profile of the motor can be freely preprogrammed and selected using a micro-processor. The maximum pump output is about 9-10L/min against 100-110mmHg afterload with overall system efficiency of 7-10%.
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A. HIRANO, Y. MITAMURA, E. OKAMOTO, T. MIKAMI
1988 Volume 17 Issue 3 Pages
831-834
Published: June 15, 1988
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To get the higher efficiency, source voltage must be chosen as high as possible unless the magnetic flux density passes through the core exceeds the saturation flux density. Using pot core of 36mm diameter, 67% and 78% of maximum system efficiency was measured when 24w were transmitted at 50kHz.In vitro enough power to drive the motor driven artificial heart was transmitted. Pump outflow of 4.0L/min. was obtained under the condition of supply voltage of 14V, drive rate of 94bpm, preload of 15mmHg, afterload of 90mmHg. The secondary part of transmission system includes the subsidiary battery which is charged in trickle method and the primary part includes some alarm functions. Feasibility of the systems were verified.
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Y. TAENAKA, H. TAKANO, S. TAKATANI, A. YAGURA, M. KINOSHITA, H. NODA, ...
1988 Volume 17 Issue 3 Pages
835-838
Published: June 15, 1988
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A total artificial heart (TAB) for smaller-sized recipients like Japanese was designed based on the stroke volume required, the principle configuration derived from the anatomical characteristics of the human chest and the dimensions obtained from the magnetic resonance imaging of 4 volunteers. The right pump connecting the tricuspid valve and the pulmonary trunk has a flat and long configuration compared with the left. The height, width and length of the right pump are 35mm, 65mm and 95mm and those of the left are 55mm, 55mm and 80mm, respectively. The maximum effective stroke volumes are 65ml for the right and 70ml for the left.
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[in Japanese]
1988 Volume 17 Issue 3 Pages
839
Published: June 15, 1988
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T. TSUTSUI, H. IJIMA, T. MITSUI, M. HORI
1988 Volume 17 Issue 3 Pages
840-843
Published: June 15, 1988
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Animal experiments were performed to obtain an adequate parameter for choosing the optimal cardiac output. Aortic characteristic impedance (Zo) was constant for excessive cardiac output, but was increased as given cardiac output was decreased. Then, systemic output demand was increased using 2, 4-dinitrophenol (DNP), a metabolic stimulant, and the circulatory responses against the change of given cardiac output was the same as that of pre-DNP state. Results indicate that it is seemed to be possible to determine the optimal systemic blood flow during the artificial circulation by detecting the changing pattern of Zo.
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Y. ABE, T. CHINZEI, K. IMACHI, K. MABUCHI, K. MAEDA, K. IMANISHI, S. H ...
1988 Volume 17 Issue 3 Pages
844-848
Published: June 15, 1988
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Artificial body constructed with artificial organs is thought to be best method for long heart preservation, if it has the same function as living body. In this philosophy, artificial circuratory system was developped experimentally, in which circuratory parameters and respilatory paremeteres were realized to bave realtime computed control, and could be kept in fixed physiological condition. The isolated heart survival time with this system was demonstrated to be about 24 hours. In this system, complete metabolic control could be thought to be required to obtain longer heart preservation time.
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Y. SUGITA, K. HARASAKI, Y. NOSE, T. ARAI
1988 Volume 17 Issue 3 Pages
847-850
Published: June 15, 1988
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The aim of this study is to evaluate in animals a unique technique for nonthoracotomy left ventricular bypass using retrograde unilateral transpulmonary blood flow originating from the left atrium and retrieved by a cuffed cannula wedged in a pulmonary artery. The left ventricular bypass flow of 0.4-3.5L/min can be obtained. The flow is dependent upon the level of left atrial pressnre and functions only when there is significant left ventricular failure. This technique has great potential use as an emergency method of support for patients in cardiogenic shock in ICU or CCU to allow time for appropriate evaluation and institution of therapy.
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Y. TAENAKA, H. TAKANO, S. TAKATANI, M. UMEZU, M. KINOSHITA, H. NODA, E ...
1988 Volume 17 Issue 3 Pages
849-852
Published: June 15, 1988
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In order to improve the results of total artificial heart (TAH) animal experiments, improvement of the surgical procedure to implant the TAH, employment of screw-in type connectors coupling a TAH with the natural tissue and rearrangement of the in- and outflow ports of the pump for adequate fitting were carried out. The cardiopulmonary bypass time was shortened to 164 min after the changes from 245 min before the improvement. The survival duration was prolonged to 18, 68 and 81 days. The degree of thrombus formation around the new type connectors was significantly reduced.
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K. MABUCHI, M. NAKAJIMA, K. IMACHI, T. CHINZEI, Y. ABE, K. MAEDA, M. A ...
1988 Volume 17 Issue 3 Pages
853-857
Published: June 15, 1988
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Recently atrial natriuretic polypeptide (ANP) has come to be suspected as one of the important factors which cause the characteristic hemodynamic failures of total artificial heart animals. In this paper, correlations between plasma ANP level and hemodynamic parameters, and between plasma ANP level and reninangiotensin-aldosterone system were studied in three cases of long survived total artificial heart goats. In conclusions obvious evidence could not be found that ANP played the important role in the hemodynamic abnormalities which were observed in total artificial heart animals.
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A. YAGURA, Y. TAENAKA, H. TAKANO, T. MATSUDA, H. IWATA, H. NODA, M. KI ...
1988 Volume 17 Issue 3 Pages
858-861
Published: June 15, 1988
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We investigated the plasma ANP levels and PRA during the artificial circulation. The results were as follows. (1) The LVAD-animals with a low LAP had low ANP values, while the LVAD-animals with a high RAP had high ANP levels. The TAH animals showed low ANP levels in the chronic postoperative phase without reacting to the high central venous pressure. (2) The LVAD or TAH-animals with a high RAP had high PRA, probably due to the high renal venous pressure.
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[in Japanese]
1988 Volume 17 Issue 3 Pages
862
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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Y. KATAHIRA, S. NITTA, T. YAMBE, N. SATO, M. MIURA, T. HONGO, Y. KAGAW ...
1988 Volume 17 Issue 3 Pages
863-866
Published: June 15, 1988
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The flow behavior within our different several types of ventricular assist devices (VADs) had been analized with the numerical method based on the quantitative flow visualization technique. In order to evaluate the in vivo flow characteristics of VAD, the chronic animal experiments were carried out using 21 goats without administration of any anti-coagulant and anti-platelet therapy. In these experiments, 9 goats (43%) survived more than 30 days and the average survival period was 26.5 days. The thrombi within VADs were observed in 5 cases (24%). According to the results of flow characteristics within VADs analized with the quantitative flow visualization technique, the contour of the junctions between the sack and the inflow and outflow tracts were improved to the smooth configuration which enhanced the rotating flow in the diastole and minimized the stagnant area within the sack. The thrombus generation of the improved VAD was significantly reduced from 67% to 7% in rate and extremely minimized in size. We concluded that these results showed the clinical readiness of our VADs.
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K. FUKAMACHI, T. ASOU, Y. NAKAMURA, Y. TOSHIMA, M. OE, A. MITANI, M. M ...
1988 Volume 17 Issue 3 Pages
867-870
Published: June 15, 1988
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To assess the effect of left heart bypass on right ventricular contractility, we evaluated right ventricular function using right ventricular end-systolic pressure-volume relationship (RV Emax) during left heart bypass in eight open chest dogs. The left heart bypass (from the left atrium and the left ventricular apex to the descending aorta) was performed with a Bio-Pump, and RV Emax was compared at various degrees of assisted flow ratio, defined as bypass flow divided by pulmonary arterial flow. RV Emax was significantly decreased at 75% and 100% assisted flow ratio compared to the control (0% assisted flow ratio). This shows that right ventricular contractilty was impaired during left heart bypass.
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S. FUKUDA, H. TAKANO, Y. TAENAKA, T. NAKATANI, H. NODA, M. KINOSHITA, ...
1988 Volume 17 Issue 3 Pages
871-874
Published: June 15, 1988
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The LVAD was pumped in a counterpulsation and at the maximum bypass from for 4-6 weeks. The results obtained are: 1)the LVAD pumping itself does not affect the RV function even for 6 weeks pumping, 2)the length of RV free-wall showed a gradual and small increase for early post operative days, it was due to increase of volume returned to the RV and the deformity of RV cavity derived from reduced LV volume, and 3)the same tendencies were seen but the length of the RV free-wall showed more increased even in LV failing heart.
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N OHKUBO, H MATSUDA, S NAKANO, S WATANABE, S OHTAKE, S SAKAKI, S TAN, ...
1988 Volume 17 Issue 3 Pages
875-878
Published: June 15, 1988
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Transmitral flow dynamics was studied with PDF to evaluate LV diastolic properties non-invasively without cessation of LHB in dogs. Transmitral peak velocities of diastolic rapid inflow (R), atrial contraction (A), mean acceleration (AC) and deceleration (DC) of R, and A/R were obtained. R, AC and DC during LHB had a correlation to (+) max dP/dt during off-LHB ana A/R had a correlation to (+) and (-)max dP/dt during off-LHB. In conclusion, diastolic indeces by PDF during LHB are considered to reflect LV function during off-LHB.
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S. HASHIMOTO, K. MABUCHI, H. ASARI, A. ISHIHARA, T. SASADA, [in Japane ...
1988 Volume 17 Issue 3 Pages
879-882
Published: June 15, 1988
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Authors' experimental results from cone-plate clot-growth-tests were applied to designing the blood flow-path in a centrifugal pump. Dimensions of space between impeller (diameter 64mm, polypropylene, rotation speed 1500rpm) and casing (polymethylmethacrylate) were determined so that velocity gradient on every part of the wall is greater than 400s
-1 by approximate calculation with Couette flow. With the designed pump, the clot growth test was performed in a mock circulation filled with canine blood at 24°C. Results show that clot does not grow between the impeller and the casing and that this designing method is effective to prevent the clot growth hydrodynamically.
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[in Japanese]
1988 Volume 17 Issue 3 Pages
883
Published: June 15, 1988
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K. TSUCHIDA, A. HASHIMOTO, S. AOMI, R. SEINO, H. KOYANAGI, A. SASAKI, ...
1988 Volume 17 Issue 3 Pages
884-887
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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Experience with 7 patients undergoing graft replacement of a thoracic aortic aneurysm by means of Bio-Pump and Heparinized Hydrophilic Polymer (H-PSD) tube is presented. During aortic cross-clamp (46-165min, average 87min), hemodynamics were stable and the maximum bypass flow of the Bio-Pump averaged 2.0±0.4L/min. A considerable reduction in the operative blood loss could be achieved. Thrombo-embolic complication was not recognized. Platelet counts, blood coagulation test (PT, APTT), and hepato-renal function immediately after operation were satisfactory. We believe that the nonthrombogenic left heart bypass provides the safest available technique for prolonged cross-clamping of the thoracic aorta.
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EVALUATION BY TRANSESOPHAGEAL COLOR DOPPLER ECHO
S. KYO, N. HANDA, S. TAKAMOTO, H. ADACHI, K. UEDA, Y. YOKOTE, R. OMOTO ...
1988 Volume 17 Issue 3 Pages
888-891
Published: June 15, 1988
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A fatal hypoxemia from left-to-right shunting owing to a patent foramen ovale (PFO) has been reported. However, detection of PFO during surgery is not always easy. We experienced one patient who developed severe perioperative hypoxemia related to PFO which was detected by postoperative transesophageal color Doppler echo (TE-2DD). Shunt flow through the PFO was fluctuated according to the grade of RV failure and ultimately became a cause of the patient's death. TE-2DD can be an effective diagnostic tool for detection and evaluation of PFO during LVAD assist.
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M. TANJI, S. HOSHINO, F. IWAYA, T. IGARI, T. ABE, K. TAKANO, M. ANDO, ...
1988 Volume 17 Issue 3 Pages
892-895
Published: June 15, 1988
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LVAD was indicated in 4 patients for CPB weaning and in one patients for LOS after acute myocardial infarction. Two patients could wean off from LVAD, however two patients died of MOF and one patient died of bleeding. Clinical evaluation of these cases suggested that total cardiac index should be maintained more than 2.5l/min/m
2 during LVAD assistance, and renal function was very important to prevent from falling MOF.
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H TAKANO, [in Japanese], [in Japanese], [in Japanese], [in Japanese], ...
1988 Volume 17 Issue 3 Pages
896-900
Published: June 15, 1988
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LVAD has been used in 16 patients, 9 of whose entire circulation was well maintained at normal level and LVAD was successfully removed. To maintain the major organ functions in normal level, systemic flow and SvO
2 should be kept above 3.0l/min/m
2 and 65%, and lactate level below 10mg/dl. Although the natural heart could recover, the most patients died of multiple organ failure which developed during prolonged ischemia prior to LVAD assistance. In clinical situation, timely use of LVAD by right judgement is important. Aortocoronary bypass should be performed within 2 hours after the onset of infarction to prevent hemorrhagic infarction. To prevent thromboembolism originated from left ventricle, anticoagulant should be administered earlier and full bypass should be avoided.
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[in Japanese]
1988 Volume 17 Issue 3 Pages
901
Published: June 15, 1988
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-Recovery process from the left ventricular failure-
T. NAKAMURA, K. HAYASHI, J. SEKI, T. NAKATANI, H. NODA, M. KINOSHITA, ...
1988 Volume 17 Issue 3 Pages
902-905
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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Bulk and regional left ventricular mechanics on the recovery process from the induced myocardial infarction by the left ventricular assist were studied on goats by in vivo chronic experiments using implantable miniature sonomicrometers. The regional work in the ischemic area and the left ventricular bulk work increased gradually, which suggested that the left ventricular assist reduces the infarcted area and recovers the myocardial function.
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-MORPHOMETRIC STUDY-
M. KINOSHITA, H. TAKANO, Y. TAENAKA, H. NODA, E. TATSUMI, A. YAGURA, H ...
1988 Volume 17 Issue 3 Pages
906-909
Published: June 15, 1988
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With using an LVAD, the maximum bypass rate (about 80% of the total cardiac output) was yielded in 2 goats for 30 days, and the limited bypass rate (around 60%) was maintained in one goat each for 30 days and 90 days. Morphometric studies of these left ventriclar myocardium were performed comparing with the control values (n=4). 1. Relative tissue volume densities of myocyte and interstitial tissue were unchanged. 2. Mean cross-sectional area of the myocyte in the maximum bypass cases was 327.4μm
2, while the control value was 451.0μm
2. 3. Relative myocyte volume densities of the myofiblils reduced to 49.7% in the maximum bypass cases and to 48.0% in the 90 days bypass case from the control value of 56.5%, and that of mitochondria decreased to 18.2% from 23.6% only in the 90 days bypass case. The LVAD induces the cardiac disuse atrophy in accordance with both the bypass rate and the duration of assistance.
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O. SUZUKI, T. HASEGAWA, M. SHIONO, K. OGASAWARA, Y. ORIME, Y. NAMIKI, ...
1988 Volume 17 Issue 3 Pages
910-913
Published: June 15, 1988
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Right ventricular failure following right ventrieular infarction, by means of right coronary artery ligation using swine, was made. The RVAD and IABP was used to compare the influences on cardiac function and the right ventricular infarcted area. Right ventricular infarcted area was evaluated by epicardial mapping ECG and myocardial regional bloood flow.
It was found that in the cases using IABP, the effect of reducing the infarcted area due to diastolic augmentation was noted, but the effect on the right ventricular support was not so much expected, while in the cases using RVAD the right ventricular pre load was reduced and the right ventricular stroke work was decreased, and the effect of reducing the infarcted area was obseaved. In concomitant use of RVAD and IABP, the demand and supply balance of myocardial oxygen was maintained satisfactory, and it was considered that this convination mode could sulvage the ischemic right ventricular myocardium, and avoid cardiogenic shock.
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T. ASOU, M. OE, R. TOMINAGA, K. FUKAMACHI, Y. TOSHIMA, Y. NAKAMURA, A. ...
1988 Volume 17 Issue 3 Pages
914-917
Published: June 15, 1988
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To know the optimal duration of cardiopulmonary bypass (CAB) assist, we evaluated the time course of functional ventricular recovery from ischemia in 18 open chest dogs. Emax, which is a load-independent index of contractility, was used. We concluded that after severe intraoperative myocardial ischemia, CPB assist was beneficial up to 60min for the recovery of cardiac function. Prolonged CAB assist (more than 60min) would not further improve cardiac function.
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[in Japanese]
1988 Volume 17 Issue 3 Pages
918
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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M. KINOSHITA, Y. TAENAKA, T. NAKATANI, H. NODA, E. TATSUMI, A. YAGURA, ...
1988 Volume 17 Issue 3 Pages
919-922
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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The unloading effect of LVAD on the myocardial energetics has been suggested on the basis of hemodynamic studies and assertained on the basis of pathological ones, but the cardiac energy levels during LVAD pumping has not been measured directly. In this study we measured cardiac high energy posphate levels, and cathecolamine levels influencing cardiac energy metabolism during LVAD pumping. The results were as follows. 1 High energy phosphate levels did not change in the normal heart group with LVAD pumping. 2 The LVAD pumping preserved high energy phosphate concentrations in the ischemic myocardium, and prevented the increase in catecholamine concentrations in the case of profound heart failure.
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N. INOUE, T. KAZUI, T. TANAKA, I. ITO, O. IZUMIYAMA, H. YOKOYAMA, S. K ...
1988 Volume 17 Issue 3 Pages
923-926
Published: June 15, 1988
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The twenty six dogs were subjected to 3hours of LAD occlusion. After releare of occlusion, Group I (n=8) had 1 hour reperfusion without LHB, Group II (n=8) had 1 hour reperfusion with LHB and Group II (n=10) had 10 minutes' RBCR on V-A bypass followed by 40 minutes' reperfusion with LHB. Significant improvement of percent recovery of regional contractility, expressed as percent control systolic shortening, was observed in Group III compared with Group I and II (38.4% in G III versus 7.1% in GI and 14.0% G II P<0.05). And significant impovement of limitation of myocardial infarct size was recognized in Group III (AN/AR; 39.0% in G III versus 69.5% in G I and 61.4% in G II, P<0.01) The present data suggests that both RBCR and LHB during reperfusion after LAD occlusion would provide improvement of left ventricular function and limitation of myocardial infarct size.
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C. K. BEH
1988 Volume 17 Issue 3 Pages
927-932
Published: June 15, 1988
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Histopathological findings, particularly in the reticuloendothelial system (RES), were studied in 9 cases who succumbed to sepsis and MOF after prolonged mechanical circulatory assist. Septicemia (100%), bleeding diastheses (66.6%), and MOF (88.9%) were associated with significantly marked RES changes (p<0.05) suggesting heightened macrophagic clearing of and engorgement with blood borne cell debris and breakdown products. Continual and excessive blood trauma may be etiologic in the pathogenesis of the observed RES changes, which strongly suggested RES depression and consequently, increased susceptibility to sepsis and MOF.
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S. MORIOKA, J. NINOMIYA, S. YAMAUCHI, N. SAIGUSA, K. HAYASHI, T. SHOJI
1988 Volume 17 Issue 3 Pages
933-936
Published: June 15, 1988
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The purpose of this study was to evaluate hemodynamic effect of newly developed balloon pumping system with synchronized blood flow assist for acute left ventricular failure. In 12 mongrel dogs with left heart failure following left coronary artery ligation, counterpulsatile flow assisted IABP (CFA-IABP) was instituted changing the flow 5%, 10%, 15%, 20%, 40%, 50% and 60% of aortic flow at control. The following results were obtained. 1) CFA-IABP increased aortic flow, carotid flow, aortic pressure and endocardial viability ratio, and reduced left atrial pressure, LVEDP and myocardial oxygen uptake at the low flow rate of 15-20% of aortic flow at control. 2) In high flow rate, hemodynamic effect of CFA-IABP was present, but not significant compared with the value in the low flow rate. In conclusion, effective support for the acute left heart failure was obtained at low flow rate in the CFA-IABP.
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[in Japanese]
1988 Volume 17 Issue 3 Pages
937
Published: June 15, 1988
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Y. KANAMORI, H. TANABE, T. SHIMONO, S. MAKINO, M. OKABE, I. YADA, M. K ...
1988 Volume 17 Issue 3 Pages
938-942
Published: June 15, 1988
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It has been discussed which is the best mode for the operation of pulsatile left heart bypass (LHB), but in discussion phase. A non-synchronous mode was often used, but in this mode the artificial heart would contract both at systolic phase and at diastolic phase of patient's own heart. So in this study, the experiments were performed in dogs to investigate the effects of non-synchronous pulsatile LHB. Pump flow was changed and peak AoSP, peakLVSP, PTB and EVR was measured by each beat. These data was sorted according to a phase of each contraction in a pump cycle. Transmitral flow dynamics was also studied. The result was that in middle and especially high flow bypass the preload was diminished at almost all phases of heart contraction in a pump cycle, but in low flow bypass the preload was not so diminished in comparison with a increase of the of afterload. We concluded that it was necessary to assist over 50% of bypass flow rate in non-synchronous pulsatile LHB.
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J. NINOMIYA, S. YAMAUCHI, H. MORIOKA, N. SAEGUSA, S. HARAGUCHI, S. OSA ...
1988 Volume 17 Issue 3 Pages
943-946
Published: June 15, 1988
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This study was to evaluate hemodynamic effect on and difference between RVAD as a pulsatile assist and centrifugal pump (CP) as a non-pulsatile assist for acute RV failure. Under general anesthesia, 8 adult dogs were instrumented through mid-sternotomy. Pressure catheters were inserted into RA, RV, PA, LA, LV and aorta, and also aortic and coronary sinus flows were measured. We ligated RV free wall and did pnlmonary artery banding (PAB). Either RVAD or CP assist was drived at flow rate of 20%, 40%, 60%, 80% of the aorfic flow at control. Both RVAD and CF supports could improve hemodynamics at any flow rate, but significantly improve at flow rate of more than 40%, although excessive increase of PA pressure was recognized. There was no significant difference of hemodynamics between the two systems, and both RVAD and CP effectively support the RV during acute R V failure with PH.
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T. SAKAMOTO, H. ARAI, A. SUZUKI
1988 Volume 17 Issue 3 Pages
951-954
Published: June 15, 1988
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Optimal timing of IABP has not been established in patients with atrial fibrillation due to its absolute irregularity. Since we observed significant correlation between preceding R-R interval and R-dicrotic notch interval, new algorithm is devised to regulate optimal timing of the balloon inflation using this regression equation.
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[in Japanese]
1988 Volume 17 Issue 3 Pages
955
Published: June 15, 1988
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T. MARUYAMA, H. ARAI, C. K. BEH, J. AMANO, T. SAKAMOTO, A. SUZUKI
1988 Volume 17 Issue 3 Pages
956-959
Published: June 15, 1988
Released on J-STAGE: December 02, 2011
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IABP can be utilized not only as a useful treatment modality but also as a diagnostic tool, so the following analysis was carried out using aortic pressure waveform recorded through the IABP catheter in 10 patients. 1. Cardiac output estimation by a Pulse-Contour Method; The correlation was well (R=0.91) within 12 hours from the calibration. 2. Evaluation of cardiac contractility by determining the peak pressure change (ΔP) and stroke volume change (ΔV) at the point of abrupt cessation of IABP (theoretically ΔP/ΔV represents Emax); When cardiac function was poor (SWI<30gm/M2(PAw≥15mmHg, SWI<20gm/M2(PAw<15mmHg), the ΔV was larger.
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Y. YOSHIOKA, H. NISHIDA, M. ENDOH, H. KOYANAGI
1988 Volume 17 Issue 3 Pages
960-963
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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We experienced three patients with the intra-aortic balloon insertion who complained the abdominal disease. This seems to have arisen because the balloon size is too large for Japanese people. We plan to make new balloons for Japanese to prevent this. We measured the diameter and the length of a portion of the thoracic aorta between the aortic arch and the celiac artery for 45 cases in order to determine appropriate sizes of intra-aortic balloons for Japanese. The relationship between the length of the thoracic aorta (X) and its diameter (Y) is Y=0.15X+6.99 (n=245, r=0.339, p<0.05). Three types of IABP balloons have thus been decided for small-than-average Japanese.
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K. EISHI, H. NISHIDA, E. IMAMURA, M. ENDO, M. HASHIMOTO, H. KOYANAGI, ...
1988 Volume 17 Issue 3 Pages
964-968
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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Since 1984, 16 patients were treated with circulatory support following weaning of cardiopulmonary bypass. 4 cases of these assist circulations were only veno-arterial bypass (VAB), 10 cases were left ventricular bypass following double ventricular bypass (DLVB), and 2 cases were left ventricular bypass using ventricular assist device (LVAD). Of 16 patients, 9 (56.2%) were successfully weaned and 6 (37.5%) remain alive until today. Successful weaning rate and long survival rate as follows; 50.0%, 50.0% in VAB group, 50.0%, 20.0% in DLVB group, 100.0%, 100.0% in LVAD group. Our results support a need to expand the use of circulatory support for postoperative cardiogenic shock and the need for future research and development.
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A. SAITO, S. EGUCHI, [in Japanese], [in Japanese], [in Japanese], [in ...
1988 Volume 17 Issue 3 Pages
969-971
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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The experiment of left heart bypass for 24 hours using heparin-coated tube and roller pump system was performed in eight dogs. Platelet counts, ACT and FDP were measured during the experiment. There was a slight decrease of platelet counts at the end of the experiment. After the experiment the dogs were sacrificed, and the autopsy findings revealed no evidence of thromboembolism. The clinical use of this circulatory-assisting system was done in five cases (four cases that could not be weaned from CPB, and one case with severe postoperative LOS). Four patients were successfuly weaned from this mechanical assist. This system is effective without anticoagulants, and the postoperative bleeding can be minimized.
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H MATSUDA, M OHTANI, K TANIGUCHI, K NISHIGAKI, N OHKUBO, S OHTAKE, Y S ...
1988 Volume 17 Issue 3 Pages
972-975
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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Two infants, 11 and 9 months of age, underwent left heart bypass after open heart surgeries using pediatric centrifugal pump. The first case was after repair of complete atrioventricular canal defect, and the other was after Senning operation for complete transposition of the great arteries. The arterial return was made to ascending aorta in both patients, and the drainage site was left atrium in one and the anatomical right ventricle in the other. Left heart bypass was weaned after 63 and 64 hours in each patient. However, both could not survive from pulmonary hypertension crysis with pneumonia in the first, and from cerebral damage after cerebral embolism in the other. This new pediatric device appeared to be very usefull in small infants and children.
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M. IMAI, M. OKADA, M. KUBOTA, K. NAKAMURA
1988 Volume 17 Issue 3 Pages
976-979
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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The early effect of left heart bypass (LHB) on left cardiac failure was studied from the view point of cardiac function after acute myocardial infarction (AMI) produced by multiple ligation of the coronary artery. LHB was initiated after cardiogenic shock due to AMI. Eighteen dogs were used and divided in 3 groups as follows. In group I, bypass flow was controlled at one half of cardiac output after AMI, and in group II, bypass flow was full at any time. In group III, LHB was not carried out as a control group. subsequently, all dogs died of progressive heart failure within 90 minutes in group III. An increase in AoP. (mean) was observed 11% in group I and 26% in group II, and a decrease in LVmax. dp/dt was recognized 9% in group I and 48% in group II, 1 hour after initiation of LHB with centrifugal pump. On the other hand, right cardiac function was studied, but no remarkable changes were revealed in group I and II before and during LHB. In conclusion, cardiac performance was satisfactorily improved by LHB with centrifugal pump. It could be concluded that the effects of cadiac support and the improvement of peripheral circulation were confirmed especially in group II in comparison with group I.
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Hiroyuki IRIE, Taiji MURAKAMI, Hirohumi IZUMOTO, Kohji TAKATA, Haruaki ...
1988 Volume 17 Issue 3 Pages
980-983
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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To maintain circulation in goats with profound biventricular failure, a pulsatile V-A bypass circuit (EUVD) was designed, which consisted of a pneumatic-driven pusher plate pump and a membrane oxygenator. It supplied a pump flow of 60-120% of native cardiac output and almost the same pulse pressure and Ao dp/dt as natural hearts to maintained total circulation for 9-23 hours.
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[in Japanese]
1988 Volume 17 Issue 3 Pages
984
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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N. SATO, Y. KAGAWA, M. MIURA, Y. AKINO, M. SADAHIRO, T. WATANABE, H. M ...
1988 Volume 17 Issue 3 Pages
985-988
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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Antithrombogenicity of VAD for postoperative ventricular failures were evaluated macroscopically in comparison with potential risk factors of thrombus formation including VAD flow and ACT. A total of 9 pumps were used in 6 cases after operation for ischemic heart diseases (2), valvular diseases (2) and congenital anomalies (2). 3 pups were exchanged due to possible or actual thrombus formation with pumping period of each device ranging 28 hrs-37 dys (mean 11.8 dys). Minute thrombi were noted at downstream side of cannula connectors of 2 pumps, which were caused by low flow pumping (1.5 l/min) and frequent ON/OFF studies. Light thrombus formations were found on sacs in two cases of which causative factors were frequent ON/OFF study and sepsis during VAD pumping, respectively. Minute thrombus formation despite of those high risks dencnstrated remarkable antithrombogenicity of devices.
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M. OKADA, M. KUBOTA, M. IMAI, K. HISANO, S. KOZAWA, K. NAKAMURA
1988 Volume 17 Issue 3 Pages
989-992
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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In the recent years IABP has been widely usedclini cally as amechanical circulatory assistance. However, there were a few patients who could not be weaned from profound cardiac failure after cardiac operation, in spite of IABP assistance. In our experimental studies onmechanical circulatory assistance for cardiogenic shock due to AMI efficacy of the LVAD was obviously revealed in comparison with another assisted circulation such as V-A bypass, or IABP+V-A bypass. Based on these experimental results, the LVAD was successfully applicated in the 68 Year-old female patient who underwent closure of ventricular septal rupture and A-C bypass for VSR following AMI. The patient was fortunately weaned from the LVAD and IABP one week after surgery. Our experiences concerning the LVAD in mechanical circulatory assistance were reported in detail.
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N. MATSUMOTO, F. MORI, K. NISHI, K. ESATO, H. MOHRI
1988 Volume 17 Issue 3 Pages
993-996
Published: June 15, 1988
Released on J-STAGE: October 07, 2011
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We evaluated the effects of the left ventricular assist device (LVAD) for regional myocardial blood flow and myocardial lactate metabolism during reperfusion after one hour occlusion of left circumfrex (LCx) artery. Sixteen mongrel dogs were divided into two groups: nine were supported with LVAD during reperfusion (LVADgroup), and seven without LVAD (Control group). There was no significant difference between two groups for heart rate, aortic pressure, and PA pressure throughout study period. Left atrial pressure was significantly low and, cardiac output, LV dp/dt, left ventricular stroke work were significantly high in the LVAD group compared to the control group. Regional myocardial blood flow in LCx area recovered to the baseline level in the LVAD group, while it remained significantly lower in the control group. The LVAD group showed a positive myocardial lactate extraction in early reperfusion period in spite of persistent lactate production in the control group. In conclusion, the unloading effect by applying LVAD during reperfusion after acute coronary artery occlusion provided the improvement in the regional myocardial blood flow and the myocardial lactate metabolism. Consequently, the left ventricular function showed better recovery after weaning from the LVAD support.
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