• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.199-203
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• 1998

Acute hemodynamic effects of CJ-18513, a non-peptide angiotensin IIreceptor antagonist, were examined in mongrel dogs treated with high frequency ventricular pacing for one week. Rapid ventricular pacing reduced mean blood pressure (mBP), Lvdp/dt and cardiac output (CO), and increased the left ventricular end-diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP). Continuous infusion of CJ-10513 at doses of 10 and 20$\mu$g/kg/min, respectively, for 30 minutes reduced mBP, LVEDP and myocardial oxygen consumption rate (MVO,) and shifted the cardiac function curve (CO-LVEDP ourve) to the left in this dog model. In conclusion, CJ-10513 decreased the preload and afterload and increased the cardiac function in dogs with pacing-induced heart failure.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.398-401
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• 1998

A 56-year-old female with a permanent unipolar pacing(VVI) system underwent elective coronary bypass surgery and mitral valve replacement. Because the unipolar sensing is subject to considerable nonmyocardial electrical noise, the pacing function may be disturbed by the use of electrocautery. Temporary atrial and ventricular bipolar epicardial leads and external generator were used for maintaining A-V sequential pacing during the use of electrocautery. Before aortic cross-clamp was released after cardiac operation, regular cardiac rhythm could spontaneously be resumed with an integrated cardioplegic strategy, avoiding the use of defibrillator

• Journal of Chest Surgery
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• v.24 no.11
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• pp.1081-1089
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• 1991

Atrial fibrillation is characterized by beat to beat irregularity of shape, size, conduction time and polarity. The mechanism of atrial fibrillation can be explained by so called "Multiple wavelet theory". The adverse effect of atrial fibrillation is the decrease of cardiac output by absence of atrial kick[10 ~ 15%] and the possibility of thrombosis in the left atrium which is dangerous to develop the thromboembolism is increased. The present study was designed to assess the effect of overdrive pacing on the suppression of recurring of atrial fibrillation after open heart surgery and the results were summarized as follows: 1. There were no significant differences of factors between converting patients and non-converting patients to normal sinus rhythm by electric cardioversion after open heart surgery. 2. Among converting patients to normal sinus rhythm, there were no significant differences of factors between study group and control group. 3. Cardiothoracic Ratio on the preoperative chest film was significantly larger in the patients of recurring atrial fibrillation within 72hrs than in the patients of maintaining normal sinus rhythm. [61.7$\pm$ 1.4% vs 67.7$\pm$2.4%, p=0.03] 4. There was a significant difference of suppressive effects between overdrive pacing group and control group among recurred cases until 24, 48, and 72hours [Fisher`s exact test ; p=0.037, p=0.076, p=0.53, respectively] 5. There was a difference of the delay of recurring of atrial fibrillation between study group and control group among recurred cases within 72 hours.[53.4$\pm$6.9hr vs. 19.3$\pm$3.8 hr, p<0.01] We think that the overdrive pacing may suppress the natural pacemaker and the converted normal sinus rhythm is maintained longer than control group during critical immediate postoperative period.ve period.

• Science of Emotion and Sensibility
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• v.12 no.1
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• pp.33-44
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• 2009

This study investigates differential impacts of the positive and negative content and the interaction with pacing, as a structural feature, on information processing while watching televised video clips with moderately intensive emotional tone. College participants watched six positive messages and six negative video clips lasting approximately 60 seconds. Heart rate was used to index attention and skin conductance was used to measure arousal. After all of the stimuli were shown, the participants performed the free recall questionnaire. The result demonstrates, first, positivity superiority on attention in which participants' heart rates were slower during positive content compared to during negative content. Secondly, negativity superiority was shown on free recall memory as participants remembered positive content better than did negative content. The result also manifests the interaction of emotional valence and pacing as the effects of pacing were less for the negatively emotional content compared to those for the positively emotional content. It is suggested that future studies should examine further about the differential and independent functions of positive and negative contents on information processing and the potential interaction with formal features.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.198-203
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• 2015

The purpose of the study is to examine the effects of pacemaker location on cardiac pumping efficacy theoretically. We used a three-dimensional finite element cardiac electromechanical model of canine ventricles with models of the circulatory system. Electrical activation time for normal sinus rhythm and artificial pacing in apex, left ventricular free wall, and right ventricular free wall were obtained from electrophysiological model. We applied the electrical activation time maps to the mechanical contraction model and obtained cardiac mechanical responses such as myocardial contractile ATP consumption, stroke work, stroke volume, ejection fraction, and etc. Among three artificial pacing methods, left ventricle pacing showed best performance in ventricular pumping efficacy.

• Research in Mathematical Education
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• v.24 no.2
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• pp.83-109
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• 2021

In the early stage of lesson enactment process, teachers use textbooks and other resources to select tasks and activities. It follows that discrepancies between textbooks and research-recommended pathways for learning may lead to concerns or issues with pacing in the classroom. To explore this idea further, this study examined the alignment between three popular standards-aligned textbooks series and volume learning trajectories. The results indicated that the standards-based textbooks examined may lack attention to important topics in the pacing of volume instruction, and suggest the need to inform both pre-service and in-service teachers about the gap between textbook lessons and volume learning trajectories so that they will be able to reflect students' thinking in volume learning trajectory to their lessons.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.962-964
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• 1987

In this paper a virtual route pacing control mechanism is introduced to the flow control of M-hop virtual route in the packet data network. The results described in this paper show us a comparison of the relationship between the throughput and the time-delay with the variation of the parameter, the normalized applied load. for the fixed window size.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.769-773
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• 2010

Systemic hypotension has been traditionally used to facilitate deployment of thoracic stent grafts. Decreasing blood pressure with vasodilating agents further increases cardiac output and, consequently, the cardiac output-mediated windsock effect during deployment. Use of rapid ventricular pacing reduces the windsock effect during stent graft deployment and allows the graft to appose to the aortic wall under zero cardiac output, thus minimizing aortic wall shear stress. In this case we report the use of transvenous rapid ventricular pacing, a safe and reproducible technique to allow precise deployment of a Valiant Captivia stent graft in the distal thoracic arch for a saccular thoracic aneurysm.

• Journal of Chest Surgery
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• v.16 no.2
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• pp.190-198
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• 1983

The management of cardiac arrhythmias by cardiac pacing has increased greatly since the treatment of complete heart block with an external transcutaneous pacemaker in 1952, followed by the use of myocardial wires connected to an external pulse generation, by external transvenous pacing, and then by transvenous pacing with implantable components in thoracic wall.By now, the three bases of modern cardiac pacing for bradyarrhythmias had been established [1] an implantable device [2] the transvenous approach [3] the ability of the pacemaker to sense cardiac activity and modify its own function accordingly. In transvenous implantation of a pacemaker, any one of four vessels at the root of the neck is suitable for passage of the electrode - cephalic vein, external jugular vein, internal jugular vein, costo-axillary branch of the axillary vein. The new technique of direct puncture of the subclavian vein, either percutaneously or after skin incision only has been made, is invaluable & is used routinely. We have experienced one 25 years old patient who had rheumatic mitral stenosis & minimum aortic regurgitation with sinus bradycardia associated with premature atrial tachycardia & another 54 years old female patient who was suffered from sick sinus syndrome with sinus bradycardia & sinus arrest. The 1st patient was taken open mitral commissurotomy & aortic valvuloplasty and then was taken atrlal pace-maker implantation through If subclavian puncture method in post-op 14 days, and the second patient was taken atrial pacemaker implantation through If subclavian puncture method. Their postop course was in uneventful & were discharged, without complication. Their condition have been good to now.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.599-605
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• 1996

A total of 249 patients undergoing isolated coronary revascularization were studied for the occurrence of postoperative atrial fibrillation(AF). Possible associations of this arrhythmia with various preoperative, intraoperative and postoperative factors were studied by univariate and multivariate analysis. The overall incidence of postoperative AF was 15%, with the median time occurence of 48 hours(mean time : 59.1 $\pm$ 56.9 hours) after arrival to the intensive care unit. Cardiac index decreased significantly after occurence of AF(p=0.001). There were no in-hospital complications in those patients with AF. Univariate studies indicated preoperative ejection fract on(EF), triglyceride level, postoperative peak CKMB isoenzpme and atrial pacing to be the dominant factor promoting postoperative AF, with an increasing prevalence in lower EF(p=0.025), triglyceride(p=0.006) and peak CKMB isoenzyme(p=0.002), and in patients with atrial pacing(p=0.001). Hospital stay(p=0.001) and late mortality(p=0.003) were significantly increased in patients with postoperative AF Multivariate analysis showed that body weight and postoperative atrial pacing to be the dominant factor promoting postoperative AF, with an increasing prevalence in over- weight patients(p=0.011) and patients with atrial pacing(p=0.001). Both univariate and multivariate analy- sis showed that the age was not a significant factor but tended to promote postoperative AF respectively (p=0.053, 0.064). After 30.1 $\pm$ 11.4 months gfollow-up, those patients with AF had sinus rhythm. We think that we must try to prevent postoperative AF after ccoronary artery bypass grafting because of its deleterio s hemodynamic effect, prolonged hospital stay, and increased late mortality.