• 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.

• 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.

• Journal of Chest Surgery
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• v.38 no.4 s.249
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• pp.312-315
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• 2005

Bleeding due to cardiac perforation by endocardial pacemaker lead is a rare complication. We report one case of left hemothorax due to right ventricular perforation after the insertion of permanent transvenous pacemaker. Operative finding showed a pacing lead penetrating right ventricle, pericardium, and left pleura sequentially, but there was no evidence of hemopericardium.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.92-95
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• 2009

Sarcoidosis is a systemic inflammatory disease with granulomatous lesions, and cardiac involvement occurs in 20~60% of patients. Isolated cardiac sarcoidosis is extremely rare, and heart transplantation can be performed, if indicated, contingent upon the absence of systemic manifestations of the disease. We present a case of isolated cardiac sarcoidosis with progressive heart failure, which was successfully managed by heart transplantation.

• The Korean Journal of Physiology
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• v.6 no.2
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• pp.31-37
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• 1972

The right cervical vagus nerve was electrically stimulated for 30 sec, and 30 minutes recording cardiac rate responses and electrocardiogram. The main purposes of the present experiment are to determine effect of stimulation frequency on the maintenance of cardiac rate responses and to determine recovery time of sinus rhythm after asystole period followed by idioventricular rhythm during prolonged electrical stimulation of the vagus, and the optimal stimulation parameters for vagal stimulation were studied as well. The results obtained are summarized as follows: 1. The maximum negative chrontropic responses were obtained with the following ranges of electrical parameters. Intensity: 3V-7V, Frequency: 20/sec-60/sec, and pulse duration: 5 msec-20 msec. 2. Compared with the responses from sympathetic effectors, cardiac rate responses to electrical stimulation of vagus nerve were well maintained with all stimulation frequencies. 3. At all stimulation frequencies except 20/sec, sinus node started to take over primary pacemaker activity when cardiac rates were restored to about 38-40/min. 4. It was indicated that upper limit of idioventricular rhythm does not exceed 38-40/min. 5. With the stimulation parameter set of 20/sec-5 msec-3 V, sinus rhythm did not appear during 30 minutes of stimulation period. Therefore, this electrical parameter set appears to be optimal for elicitation of prolonged and maximum cardiac rate responses by vagal stimulation.

• 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.11 no.3
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• pp.326-332
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• 1978

There appears some conduction defects frequently after total correction of Tetralogy of Fallot. Common defect is right bundle branch block due to surgical intervention. We experienced complete A-V block which occured 3 months later after total correction of Tetralogy of Fallot in a 8 year old boy. The patient was completely free of any A-V block after the operation for 3 months, and sudden onset of A-V block with coupled premature ventricular contractions resulted him in shock state during the attack of severe bronchopneumonia for 4 days prior to the second visit. Emergency implantation of Cordis demand type temporary pacemaker was necessary to control the complete heart block with bradyarrhythmia and frequent ventricular fibrillation. Permanent cardiac pacemaker was implanted two weeks later as indicated with Cordis Stanicor lambda demand pacemaker, and the patient was discharged uneventfully on the 8th post implantation day with the heart rate of 72/min. Another 3 months after the implantation, the patient was transported to this hospital as dead on arrival after an accidental fall from a 2 meter height, and all possible cardiopulmonary resuscitation was performed for 60 minutes at the emergency room in vain. Autopsy was done to find out the cause of sudden death and the etiology of complete heart block. Microscopic focal infarctions with scar formation were noted along the course of conduction system in the interventricular septum, which might be the main cause of complete heart block during the attack of severe bronchopneumonia complicated with acute bacterial endocarditis. The tip of the pacemaker wire was slipped from the granulation scar at the apex of the right ventricular cavity, and this might be the direct cause of pacing failure and death.

• Korean Journal of Radiology
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• v.22 no.11
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• pp.1918-1928
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• 2021

Objective: With the recent development of various MRI-conditional cardiac implantable electronic devices (CIEDs), the accurate identification and characterization of CIEDs have become critical when performing MRI in patients with CIEDs. We aimed to develop and evaluate a deep learning-based algorithm (DLA) that performs the detection and characterization of parameters, including MRI safety, of CIEDs on chest radiograph (CR) in a single step and compare its performance with other related algorithms that were recently developed. Materials and Methods: We developed a DLA (X-ray CIED identification [XCID]) using 9912 CRs of 958 patients with 968 CIEDs comprising 26 model groups from 4 manufacturers obtained between 2014 and 2019 from one hospital. The performance of XCID was tested with an external dataset consisting of 2122 CRs obtained from a different hospital and compared with the performance of two other related algorithms recently reported, including PacemakerID (PID) and Pacemaker identification with neural networks (PPMnn). Results: The overall accuracies of XCID for the manufacturer classification, model group identification, and MRI safety characterization using the internal test dataset were 99.7% (992/995), 97.2% (967/995), and 98.9% (984/995), respectively. These were 95.8% (2033/2122), 85.4% (1813/2122), and 92.2% (1956/2122), respectively, with the external test dataset. In the comparative study, the accuracy for the manufacturer classification was 95.0% (152/160) for XCID and 91.3% for PPMnn (146/160), which was significantly higher than that for PID (80.0%,128/160; p < 0.001 for both). XCID demonstrated a higher accuracy (88.1%; 141/160) than PPMnn (80.0%; 128/160) in identifying model groups (p < 0.001). Conclusion: The remarkable and consistent performance of XCID suggests its applicability for detection, manufacturer and model identification, as well as MRI safety characterization of CIED on CRs. Further studies are warranted to guarantee the safe use of XCID in clinical practice.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.55-58
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• 2003

Segmented polyurethanes have been widely used for various commercial and experimental blood-contacting and tissue-contacting applications such as vascular prostheses, blood pumps, heart valves, pacemaker lead wire insulation, catheters, artificial hearts, and cardiac assist devices due to their generally favorable physical and mechanical properties, as well as fairly good biocompatibility and antithrombogenicity characteristics. (omitted)

• Archives of Plastic Surgery
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• v.44 no.1
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• pp.34-41
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• 2017

Background The current indications of cardiac implantable electronic devices (CIEDs) have expanded to include young patients with serious cardiac risk factors, but CIED placement has the disadvantage of involving unsightly scarring and bulging of the chest wall. A collaborative team of cardiologists and plastic surgeons developed a technique for the subpectoral placement of CIEDs in young female patients via a transaxillary approach. Methods From July 2012 to December 2015, subpectoral CIED placement via an axillary incision was performed in 10 young female patients, with a mean age of 25.9 years and mean body mass index of $20.1kg/m^2$. In the supine position, with the patient's shoulder abducted, an approximately 5-cm linear incision was made along one of the deepest axillary creases. The submuscular plane was identified at the lateral border of the pectoralis major, and the dissection continued over the clavipectoral fascia until the subpectoral pocket could securely receive a pulse generator. Slight upward dissection also exposed an entrance to the subclavian vein, allowing the cardiology team to gain access to the vein. One patient with dilated cardiomyopathy underwent augmentation mammoplasty and CIED insertion simultaneously. Results One case of late-onset device infection occurred. All patients were highly satisfied with the results and reported that they would recommend the procedure to others. Conclusions With superior aesthetic outcomes compared to conventional methods, the subpectoral placement of CIEDs via a transaxillary approach is an effective, single-incision method to hide operative scarring and minimize bulging of the device, and is particularly beneficial for young female or lean patients.