• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.187-188
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• 1998

A low cost, low power, portable cardiac event recorder as a tether-free biological signal processor was developed. Dual channel ECG signals are sampled at 128Hz in 12 bits resolution. Sampled data are continuously recorded in a circular buffer. If event button is pressed, 2 minutes data before and after the event are recorded in 512 Kbyte SRAM. Total 11 events can be recorded. Data can be transferred to PC through RS-232 protocol. It operates for two months by a half AA size 3.6V Lithium battery. The system size is $55\times55\times13[mm^3]$.

• Korean Journal of Adult Nursing
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• v.26 no.5
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• pp.573-583
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• 2014

Purpose: Cardiac arrest has multiple characteristics that need to be approached as an integrated method according to the various changes in the body system. This study was performed to develop a useful guideline for early detection of cardiac arrest by revealing the attributes of cardiac arrest through a concept analysis. Methods: This study was conducted according to the Walker and Avant's concept analysis method. Systematic literature review and in-depth interview with nurses who experienced cardiac arrest situation were conducted. Based on the literature reviews and in-depth interviews with nurses, the attributes and the empirical referents of the concept of cardiac arrest were elicited. Results: The definable attributes of cardiac arrest were 1) loss of consciousness, 2) abnormal respiratory condition, 3) abnormal cardiovascular signs. Cardiac arrest was found to occur by several antecedents such as cardiac problem, non-cardiac problem, or general problem, whereas ischemia and re-perfusion injury, which can lead to multiple organ failure and death, were derived as consequences. Conclusion: In this study, the concept analysis eliciting attributes and empirical referents is found to be useful as a guideline for understanding and managing cardiac arrest. Based on these findings, clinical providers are expected to make a precise and rapid decision on cardiac arrest and respond quickly, which may increase survival rate of the patients underwent the arrest event.

• Journal of Chest Surgery
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• v.56 no.6
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• pp.394-402
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• 2023

Background: The optimal choice of valve substitute for aortic valve replacement (AVR) in pediatric patients remains a matter of debate. This study investigated the outcomes following AVR using mechanical prostheses in children. Methods: Forty-four patients younger than 15 years who underwent mechanical AVR from March 1990 through March 2023 were included. The outcomes of interest were death or transplantation, hemorrhagic or thromboembolic events, and reoperation after mechanical AVR. Adverse events included any death, transplant, aortic valve reoperation, and major thromboembolic or hemorrhagic event. Results: The median age and weight at AVR were 139 months and 32 kg, respectively. The median follow-up duration was 56 months. The most commonly used valve size was 21 mm (14 [31.8%]). There were 2 in-hospital deaths, 1 in-hospital transplant, and 1 late death. The overall survival rates at 1 and 10 years post-AVR were 92.9% and 90.0%, respectively. Aortic valve reoperation was required in 4 patients at a median of 70 months post-AVR. No major hemorrhagic or thromboembolic events occurred. The 5- and 10-year adverse event-free survival rates were 81.8% and 72.2%, respectively. In univariable analysis, younger age, longer cardiopulmonary bypass time, and smaller valve size were associated with adverse events. The cut-off values for age and prosthetic valve size to minimize the risk of adverse events were 71 months and 20 mm, respectively. Conclusion: Mechanical AVR could be performed safely in children. Younger age, longer cardiopulmonary bypass time and smaller valve size were associated with adverse events. Thromboembolic or hemorrhagic complications might rarely occur.

• Journal of Chest Surgery
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• v.47 no.2
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• pp.160-162
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• 2014

Cardiac involvement in hydatid disease is more seldom than the involvement of the liver and the lungs. Cardiac cyst hydatid disease is diagnosed incidentally or by means of symptoms such as dyspnea and angina pectoris. Here, we present the case of a 45-year-old male patient who underwent open heart surgery for a randomly detected cardiac cyst hydatid during investigations carried out in a healthcare institution after accidentally falling from height. On the other hand, this patient did not have any complaints associated with hydatid disease before this event.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.275-278
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• 1997

Standard methods estimating the power spectral density(PSD) from an irregularly sampled cardiac event series require deriving a new evenly-spaced signal applicable to those methods. To avoid that requirement, in this study, the power spectrum of heart rate variability was estimated by Lomb-Scargle's algorithm, which is a means of obtaining PSD estimates directly from irregularly sampled timeseries observed in astronomy. To assess the performance of Lomb-Scargle algorithm in the power spectral analysis of heart rate variability, it was applied to various cardiac event series derived through integral pulse frequency modulation model(IPFM) simulation and from real ECG signals, and the resultant power spectra was compared with those obtained by a conventional method based on the FFT. In result, it is concluded that Lomb-Scargle's periodogram is very effective in the power spectral analysis of heart rate variability, especially in the presence of arrhythmia and/or dropouts of cardiac events.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.273-281
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• 1999

Purpose: We investigated whether myocardial SPECT had additional usefulness to clinical, functional or surgical indices for the preoperative evaluation of cardiac risks in noncardiac surgery. Materials and Methods: 118 patients (M: F=66: 52, $62.7{\pm}10.5$ years) were studied retrospectively. Eighteen underwent vascular surgeries and 100 nonvascular surgeries. Rest T1-20l/ stress Tc-99m-MIBI SPECT was performed before operation and cardiac events (hard event: cardiac death and myocardial infarction; soft event: ischemic ECG change, congestive heart failure and unstable angina) were surveyed through perioperative periods ($14.6{\pm}5.6$ days). Clinical risk indices, functional capacity, surgery procedures and SPECT findings were tested for their predictive values of perioperative cardiac events. Results: Perioperative cardiac events occurred in 25 patients (3 hard events and 22 soft events). Clinical risk indices, surgical procedure risks and SPECT findings but functional capacity were predictive of cardiac events. Reversible perfusion decrease was a better predictor than persistent decrease, Multivariate analysis sorted out surgical procedure risk (p=0.0018) and SPECT findings (p=0.0001) as significant risk factors. SPECT could re-stratify perioperative cardiac risks in patients ranked with surgical procedures. Conclusion : We conclude that myocardial SPECT provides additional predictive value to surgical type risks as well as clinical indexes or functional capacity for the prediction of preoperative cardiac events in noncardiac surgery.

• Journal of Chest Surgery
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• v.54 no.5
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• pp.383-388
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• 2021

Background: Achieving external access to and manual occlusion of the left atrial appendage (LAA) during minimally invasive mitral valve surgery (MIMVS) through a small right thoracotomy is difficult. Occlusion of the LAA using an epicardial closure device seems quite useful compared to other surgical techniques. Methods: Fourteen patients with atrial fibrillation underwent MIMVS with concomitant surgical occlusion of the LAA using double-layered endocardial closure stitches (n=6, endocardial suture group) or the AtriClip Pro closure device (n=8, AtriClip group) at our institution. The primary safety endpoint was any device-related adverse event, and the primary efficacy endpoint was successful complete occlusion of blood flow into the LAA as assessed by transthoracic echocardiography at hospital discharge. The primary efficacy endpoint for stroke reduction was the occurrence of ischemic or hemorrhagic neurologic events. Results: All patients underwent LAA occlusion as scheduled. The cardiopulmonary bypass and aortic cross-clamp times in the endocardial suture group and the AtriClip group were 202±39 and 128±41 minutes, and 213±53 and 136±44 minutes, respectively (p=0.68, p=0.73). No patients in either group experienced any device-related serious adverse events, incomplete LAA occlusion, early postoperative stroke, or neurologic complication. Conclusion: Epicardial LAA occlusion using the AtriClip Pro during MIMVS in patients with mitral valve disease and atrial fibrillation is a simple, safe, and effective adjunctive procedure.

• Journal of Korean Academy of Nursing
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• v.17 no.2
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• pp.110-115
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• 1987

This study was done in order to help alleviate or prevent the anxiety resulting from cardiac catheterization among adult patients. This goal may be re-ached through providing relaxation techenique to the patients. Such an informativeness would make it possible to establish a basis for comprehensive nursing intervention. The results of this study are summarized as fellows: 1. The first hypothesis:“The experimental group with relaxation informativeness will have less score of state anxiety level before cardiac catheterization than the control group without relaxation informativeness”was accepted. (t=3.72, p=.001). 2. The second hypothesis: “The experimental group with relaxation technique informativeness will have less score of distress level during the procedure than the control group without relaxation technique informativeness”was accepted. (t=2.36, p=.023) 3. Additional analysis; It is seen that most cardiac patients were satisfied with precardiac catheterization procedure information provided by medical teams. (experimental group: 90%, control group: 85%) The relaxation technique informativeness contributed to the decrease of anxiety level. Patients showed interest in reusing the relaxation technique informativeness in the event of further need. In conclusion, the researcher thinks that it is necessary that nurses provide Patients with relaxation technique to reduce the anxiety level with cardiac catheterigation. This will enable them to practice effective comprehensive nursing.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.324-333
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• 2021

Objective: The clinical course of an individual patient with heart failure is unpredictable with left ventricle ejection fraction (LVEF) only. We aimed to evaluate the prognostic value of cardiac magnetic resonance (CMR)-derived myocardial fibrosis extent and to determine the cutoff value for event-free survival in patients with non-ischemic cardiomyopathy (NICM) who had severely reduced LVEF. Materials and Methods: Our prospective cohort study included 78 NICM patients with significantly reduced LV systolic function (LVEF < 35%). CMR images were analyzed for the presence and extent of late gadolinium enhancement (LGE). The primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, heart transplantation, implantable cardioverter-defibrillator discharge for major arrhythmia, and hospitalization for congestive heart failure within 5 years after enrollment. Results: A total of 80.8% (n = 63) of enrolled patients had LGE, with the median LVEF of 25.4% (19.8-32.4%). The extent of myocardial scarring was significantly higher in patients who experienced MACE than in those without any cardiac events (22.0 [5.5-46.1] %LV vs. 6.7 [0-17.1] %LV, respectively, p = 0.008). During follow-up, 51.4% of patients with LGE ≥ 12.0 %LV experienced MACE, along with 20.9% of those with LGE ≤ 12.0 %LV (log-rank p = 0.001). According to multivariate analysis, LGE extent more than 12.0 %LV was independently associated with MACE (adjusted hazard ratio, 6.71; 95% confidence interval, 2.54-17.74; p < 0.001). Conclusion: In NICM patients with significantly reduced LV systolic function, the extent of LGE is a strong predictor for long-term adverse cardiac outcomes. Event-free survival was well discriminated with an LGE cutoff value of 12.0 %LV in these patients.

• Journal of Chest Surgery
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• v.23 no.6
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• pp.1263-1269
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• 1990

Two patients with uncorrectable cyanotic cardiac anomalies underwent total cavopulmonary shunt[modified Fontan operation]. Case I was a 14 years old male with dyspnea and cyanosis after birth. Aortogram showed TGA combined with overriding of aorta, pulmonary stenosis, complete atrioventricular septal defect, interruption of inferior vena cava, and situs inversus totalis. We had performed total cavopulmonary shunt using with 16 mm Gortex Graft in single atrium to bypass the hepatic vein to pulmonary artery. Postoperatively, patient sustained low PaCO2 and low cardiac output and then expired at 19th postoperative day. The cause of death of the patient would be low cardiac output. Case II was a 6 years old female with dyspnea and cyanosis after birth. Aortogram showed tricuspid atresia[Type IIb], transposition of great arteries, atrial septal defect, ventricular septal defect and pulmonary stenosis, We had performed total cavo-pulmonary shunt using intraatrial baffle[tunnel] with Goretex patch. The postoperative course of this patient was good without event.