• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.182-189
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• 2001

Single-pass VDD pacemakers have been used as a result of simple implantation procedures and generally reliable atrial tracking that ensures an A-V sequence pacing. However, there is a controversy over their reliabilities of atrial tracking. As a new sensing method for reliable atrial tracking, a simple automatic pacemaker sensing algorithm was implemented and evaluated to validate its benefits in sensing depolarization waves of Single-pass VDD atrial electrograms. The automatic sensing algorithm had a predetermined sensing dynamic range and the sensitivity level was controlled as 50% of the average of two most recently sensed intrinsic amplitudes. The behavior of the automatic sensing algorithm in the Single-pass VDD atrial electrograms was analyzed and characterized. It was observed that the automatic sensing algorithm was more effective than a conventional fixed threshold method to accurately detect and track p-waves in Single-pass VDD electrograms.

• The Journal of Korean Association of Computer Education
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• v.19 no.2
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• pp.99-114
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• 2016

The transient information effect occurs when long and complex transient information disappear before the learner has time to adequately process it or link it with new information. This study aimed to explore the impact of the transient information effect on multimedia learning efficiency within the cognitive load perspective and how segmentation and pacing of instructional materials interact with the transient information effect. The results revealed that the visualonly instruction(a diagram with long and complex texts) was more efficient than the audiovisual instruction(a diagram with long and complex spoken texts). The overall results suggested that using long and complex spoken texts with a diagram can have a negative impact on learning unless the transient information effect are reduced through segmentation and learner-paced instructions.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.288-296
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• 2001

The behavior of declawed emus in a farm environment has not been described despite its importance in the husbandry and welfare of the emu. This study examined whether declawing of emus causes chronic pain resulting in permanent changes in the locomotor and general behavior of declawed yearling emus compared to emus not declawed. One group of 40 emus were declawed on the day of hatch by removing the distal phalangeal joint using a Lyon beak-trimming machine. Another group of 40 emus not declawed were the controls. Declawed emus one year of age were allocated to a paddock $250m{\times}125m$, while the control group was placed in an adjoining paddock of the same dimensions. One hour video records of individual emus from each treatment were made from 08:00 and 17:00 h over 2 periods; firstly when food and water was available and secondly during a period when food and water was not available after being withdrawn overnight. Inactive, ingestive, posture change, grooming, aggressive and locomotor behaviors were monitored from the videotape. There was no behavioral evidence to indicate loss of locomotor ability of declawed emus or to suggest declawed emus were suffering from severe chronic pain as indicated by declawed emus engaging in significantly more bouts (p<0.05) and time of searching (p<0.05). Declawed emus also engaged in less stereotype pacing (p<0.05) indicating they were under less stress and not as frustrated as control birds which engaged in more step pushing behavior (p<0.05). Modelling analysis showed that pecking behavior in birds was most closely related to foraging behavior. Birds subject to pecking attacks demonstrated higher levels of stereotype behavior presumably as a method to cope with stress. The behavioral evidence in this study would indicate that declawing does not compromise the locomotor ability of emus and has the benefit of improving the social structure in the groups by reducing stereotype behavior and aggression.

• Archives of Plastic Surgery
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• v.32 no.6
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• pp.753-756
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• 2005

In the cases of severe arrythmia and conduction failure, a permanent implanted pacemaker is considered an essential treatment modality with less complication rate, broad indications and low morbidity. However, some pacemakers needs to be removed or replaced due to infection, in need of a lead upgrade, elective replacement, conduction failure or insulation failure. The most common indication for pacemaker extraction is infection. Conservative treatments such as administration of intravenous antibiotics and limitation of debridement are not effective and the removal of the entire pacing system is considered to be the best approach to pacemaker pocket infection. Although a locking stylet, a laser sheath and other newer methods of transvenous lead extraction have been proven to be effective, all leads cannot be removed. Moreover, major complications such as, cardiac tamponade and respiratory arrest during leads extraction procedure should not be ignored. We experienced two cases of exposed pacemakers in the subclavicular region. After removing the pacemaker body, exposed proximal lead was pulled out and cut off. The end of remnant external insulation tube was tied to prevent infection propagation between external insulation tube and inner metalic coil. Wounds were covered by local flap coverage. No other problems were detected during the one-year follow-up. Since there are few reports on lead-preserving method of treating limited infection of exposed pacemakers, we would like to present our new method for treating exposed pacemakers.

• Safety and Health at Work
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• v.4 no.3
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• pp.156-159
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• 2013

Background: Cardiac pacemakers are known to be susceptible to strong electromagnetic fields (EMFs). This in vivo study investigated occurrence of electromagnetic interference with pacemakers caused by common environmental sources of EMFs. Methods: Eleven volunteers with a pacemaker were exposed to EMFs produced by two mobile phone base stations, an electrically powered commuter train, and an overhead high voltage transmission lines. All the pacemakers were programmed in normal clinically selected settings with bipolar sensing and pacing configurations. Results: None of the pacemakers experienced interference in any of these exposure situations. However, often it is not clear whether or not strong EMFs exist in various work environments, and hence an individual risk assessment is needed. Conclusions: Modern pacemakers are well shielded against external EMFs, and workers with a pacemaker can most often return to their previous work after having a pacemaker implanted. However, an appropriate risk assessment is still necessary after the implantation of a pacemaker, a change of its generator, or major modification of its programming settings.

• Journal of Chest Surgery
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• v.27 no.6
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• pp.460-471
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• 1994

Between Feb. 1990 and Aug. 1993, 180 cases of the open heart surgery were performed under cardiopulmonary bypass in the Department of Thoracic & Cardiovascular surgery, Gil General Hospital. There were 83 cases with congenital heart diseases [CHD] and 97 cases with acquired heart diseases [AHD]. The CHD consisted of 78 acyanotic[mortality: 3.8 %] and 5 cyanotic cases with heart anomaly[mortality:l case]. The AHD were 97 cases, which contained 53 valvular, 27 ischemic heart diseases, 10 aortic diseases, 5 cases with myxoma, 1 case with post-infarct VSD, and 1 case with removal of infected pacing wire in right ventricle. In the 53 valvular heart diseases, there were 45 cases with valve replacement[MVR 27, AVR 9,MVR + AVR 9] and 8 cases with valvuloplasty. The number of the implanted prosthetic valves were 53. In MVR, 25 St. Jude, 6 Sorin, 3 Carpentier-Edward and 2 Intact medical valves were used. In aortic position, 13 St. Jude, 3 Sorin and 1 Intact medical valves were applied. The operative mortality was 5.6 % [3/53]. The annuloplasty applying artificial ring was performed in 17 patients[4 cases associated with MVR] and the number of the implanted ring was 19, which included 14 Duran ring[10 mitral, 4 tricuspid] and 5 Carpentier ring [3 mitral, 22 tricuspid]. In the 27 ischemic heart diseases, there were 9 cases with left main coronary artery lesions, 7 one vessel, 5 two vessels, and 6 three vessels. Average number of anastomosis was 2.8 per patient. The operative mortality was 14.3 % [4/27]. Among the 10 patients with aortic diseases, 7 cases were aortic dissection[type A: 5, type B: 2] and 3 cases were descending thoracic aortic aneurysm. The operative morality occurred in 3 cases. The overall mortality and the operative mortality of congenital and acquired heart disease was 7.8 %, 4.8% and 10.4%, respectively.

• Journal of Yeungnam Medical Science
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• v.31 no.2
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• pp.113-116
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• 2014

A 52-year-old man was referred to our hospital due to fever and myalgia that occurred 2 weeks earlier. He showed a complete atrioventricular block on his electrocardiogram, and his vital signs were unstable. On his transthoracic echocardiograph, the 1.5 cm vegetation in the aortic valve with severe aortic regurgitation suggested infective endocarditis. His transesophageal enchocardiograph showed abscess in his mitral-aortic intervalvular fibrosa and vegetation was suspected on his anterior mitral valve leaflet. The patient underwent an emergent operation for valve replacement with temporary epicardial pacing. Intraoperatively, the septal leaflet of his tricuspid valve was injured during the debridement of the abscess pocket that was extended to the membranous septum. The aortic, mitral, and tricuspid mechanical valves were replaced with annular reconstruction without complications. After 14 days of intravenous antibiotics, we successfully changed the epicardial pacemaker into a transvenous DDD-type permanent pacemaker by placing a left ventricular lead via the coronary sinus and an atrial lead in the right atrium appendage. The patient was discharged in a tolerable state and was examined uneventfully in our hospital's outpatient clinic for 8 months.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.465-470
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• 2019

This study was conducted to analyze the lap time of the K-1 1000m final race of men's general division and to develop strategies to adjust the pace for the intervals to improve the performance. We measured the lap time of the final race of the 99 th National Sports Festival by 250m intervals and compared them with the data of the World Championship finals held in 2018. The final average record of domestic top-ranked players was 248.651 seconds, and the top international's 210.826 seconds. There was a time gap of 38 seconds in the record. In lap-time, it was 8, 11, 6, and 13 seconds behind every 250m. World Championship players used the Fast-Maintain-Maintain-Spurt strategy while domestic players used the pacing strategy of Fast-Slow-Fast-Slow. In order to improve the performance of domestic players, it is necessary to adjust overall pace control strategies to maintain the pace after the quick start and to spurt at the last lap.

• Journal of The Korean Society of Clinical Toxicology
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• v.19 no.2
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• pp.133-138
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• 2021

Glufosinate-containing herbicides is a non-selective herbicide commonly used worldwide. As the use of them increased gradually since paraquat was banned in 2012, the number of suicides by their ingestion is also increasing continuously. Complications of glufosinate-containing herbicide poisoning include various central nervous system (CNS) toxicities such as convulsions, loss of consciousness, memory impairment, and respiratory depression, which may be accompanied by hemodynamic changes such as bradycardia and hypotension. However, it is very rare that arrhythmias other than bradycardia occurred and Takotsubo cardiomyopathy was combined due to cardiotoxicity. A 71-year-old female patient was transferred to our hospital after ingesting 500 mL of glufosinate-containing herbicide and receiving 5 L of gastric lavage at a local hospital. A few hours later, she presented stuporous mentality, respiratory depression, and convulsions, and was accompanied by hypotension and bradycardia. On the second day of admission, electrocardiogram (ECG) showed bradycardia and QTc prolongation with hemodynamic Instability. Accordingly, we conducted the early treatment with continuous renal replacement therapy (CRRT) and the application of temporary cardiac pacemaker. An echocardiogram demonstrated decreased ejection fraction (EF) and Takotsubo cardiomyopathy on the third day of admission. Then, she was discharged safely with conservative treatment. At the follow-up after 1 year, Takotsubo cardiomyopathy, EF and QTc prolongation were recovered on echocardiogram and ECG. Because cardiac toxicity after glufosinate-containing herbicide poisoning may cause life-threatening consequences, caution is required while treating the patient. Therefore, if electrocardiogram changes are seen in the elderly with a large amount of glufosinate herbicide ingestion, additional cardiac function test through echocardiography should be concerned, and early treatment through CRRT or artificial cardiac pacing should be considered.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.2
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• pp.111-116
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• 2023

We provided general anesthesia management to a patient with advanced atrioventricular block, which was discovered in the remote period after open-heart surgery. A 21-year-old man with Noonan syndrome was scheduled to undergo excision of a median intramandibular tumor. At 2 months of age, the patient underwent endocardial repair for congenital heart disease. During our preoperative examination, an atrioventricular block was detected, which had not been previously noted. Emergency drugs were administered, and a transcutaneous pacemaker was placed. During anesthesia induction, mask ventilation was easy, and intubation was performed smoothly using a video laryngoscope. The transcutaneous pacemaker was activated in demand mode at a pacing rate of 50 cycles/min approximately throughout the anesthesia time, and the hemodynamic status remained stable. The effect of intraoperatively administered atropine was brief, lasting only a few seconds. Although body movements due to thoracoabdominal muscle spasm were observed during pacemaker activation, they did not interfere with surgery. In postoperative patients with congenital heart disease, an atrioventricular block may be identified in the remote period, and preoperative evaluation should be based on this possibility. In addition, during anesthesia management, it is important to prepare multiple measures to maintain hemodynamic status.