만성 폐쇄성 폐질환 환자에서 ST 분절 상승 심전도를 보인 자발성 기흉 1예

김지숭 ( Ji Soong Kim ),이은영 ( Eun Young Lee ),홍승표 ( Seung Pyo Hong ),오창교 ( Chang Kyo Oh ),이정훈 ( Jung Hoon Lee ),문인태 ( In Tae Moon ),손영석 ( Young Seok Sohn ),신정훈 ( Jeong Hun Shin ) 전북대학교 의과학연구소 2014 全北醫大論文集 Vol.38 No.2

Chest pain and dyspnea are the dominant manifestations in various acute chest conditions. Electrocardiography is one of the most important diagnostic tools used in the differential diagnosis of these conditions. In the majority of cases, electrocardiographic abnormalities suggest cardiac problems. However, there are many non-cardiovascular diseases that may affect electrocardiography. We experienced a case of a 60-year-old man who developed spontaneous pneumothorax associated ST-segment elevation on electrocardiography during the treatment of acute exacerbation of chronic obstructive pulmonary disease. Our case reminds us of the importance of meticulous physical examination as well as accurate analysis of uncommon electrocardiographic alterations.

Determination of optimal tip position of peripherally inserted central catheters using electrocardiography: a retrospective study

Jung Ki Tae,Kelly Linda,Kuznetsov Alexandra,Sabouri A. Sassan,Lee Kichang 대한마취통증의학회 2023 Korean Journal of Anesthesiology Vol.76 No.3

Background: Accurate tip positioning of a peripherally inserted central catheter (PICC) is crucial for optimal drug delivery and avoiding complications. The objective of this study was to evaluate the amplitude ratios of intravascular electrocardiography (ivECG) and external electrocardiography (exECG) according to the tip location.Methods: This retrospective study analyzed ivECG, exECG, and chest X-ray (CXR) of 278 patients who underwent a PICC procedure. The tip-to-carina distance (TCD) was measured using vertebral body units (VBU) on CXR. Tip locations were categorized as follows: Zone 1, malposition (TCD < 0.8 VBU); Zone 2, suboptimal (0.8 VBU ≤ TCD < 1.5 VBU); Zone 3, optimal (1.5 VBU ≤ TCD ≤ 2.4 VBU); Zone 4, deep (TCD > 2.4 VBU). The amplitude ratios between ivECG and exECG and within ivECG were compared in each zone.Results: The ivECG/exECG amplitude ratios of P-wave (Piv/Pex) and QRS-complex (QRiv/QRex and RSiv/RSex) in Zone 3 were significantly higher than in Zones 1 and 2 (adjusted P < 0.05). The ivECG amplitude ratios of the P-wave and QRS-complex (Piv/QRiv and Piv/RSiv) were significantly lower in Zone 3 than in Zones 1 and 2 (adjusted P < 0.001). The calculated TCD using stepwise multiple regression analysis was estimated to be 1.121 + 0.078 × Piv/Pex – 0.172 × Piv/QRiv.Conclusions: Though caution is required, amplitude ratios such as Piv/Pex and Piv/QRiv can help determine tip location during the PICC catheterization procedure.

Dynamic Changes in Electrocardiographic Findings Between Initial and Follow-up Electrocardiography: The Role of the T/QRS Ratio

이재훈,최유리 대한응급의학회 2021 대한응급의학회 학술대회초록집 Vol.2021 No.2

Development and Validation of Deep-Learning Algorithm for Electrocardiography-Based Heart Failure Identification

Joon-myoung Kwon,Kyung-Hee Kim,Ki-Hyun Jeon,Hyue Mee Kim,Min Jeong Kim,Sung-Min Lim,Pil Sang Song,Jinsik Park,Rak Kyeong Choi,Byung-Hee Oh 대한심장학회 2019 Korean Circulation Journal Vol.49 No.7

Background and Objectives: Screening and early diagnosis for heart failure (HF) are critical. However, conventional screening diagnostic methods have limitations, and electrocardiography (ECG)-based HF identification may be helpful. This study aimed to develop and validate a deep-learning algorithm for ECG-based HF identification (DEHF). Methods: The study involved 2 hospitals and 55,163 ECGs of 22,765 patients who performed echocardiography within 4 weeks were study subjects. ECGs were divided into derivation and validation data. Demographic and ECG features were used as predictive variables. The primary endpoint was detection of HF with reduced ejection fraction (HFrEF; ejection fraction [EF]≤40%), and the secondary endpoint was HF with mid-range to reduced EF (≤50%). We developed the DEHF using derivation data and the algorithm representing the risk of HF between 0 and 1. We confirmed accuracy and compared logistic regression (LR) and random forest (RF) analyses using validation data. Results: The area under the receiver operating characteristic curves (AUROCs) of DEHF for identification of HFrEF were 0.843 (95% confidence interval, 0.840–0.845) and 0.889 (0.887–0.891) for internal and external validation, respectively, and these results significantly outperformed those of LR (0.800 [0.797–0.803], 0.847 [0.844–0.850]) and RF (0.807 [0.804–0.810], 0.853 [0.850–0.855]) analyses. The AUROCs of deep learning for identification of the secondary endpoint was 0.821 (0.819–0.823) and 0.850 (0.848–0.852) for internal and external validation, respectively, and these results significantly outperformed those of LR and RF. Conclusions: The deep-learning algorithm accurately identified HF using ECG features and outperformed other machine-learning methods.

국소관련간질 환자의 발작 전후 심박수 변화

정은혜,김원섭,양혜란,윤영신,이규선,최경규,박기덕,이향운 대한신경과학회 2010 대한신경과학회지 Vol.28 No.3

Background: Epileptic seizures can be associated with changes in autonomic functions. This study evaluated heart rate (HR) changes at the transition from the preictal to the ictal state in patients with epileptic seizures, and investigated whether peri-ictal HR changes can help to predict electroencephalography (EEG) seizures prior to their onset. Methods: We retrospectively studied 94 seizures in 33 patients who underwent video-EEG monitoring with scalp EEG and electrocardiography. The existence and initial timing of HR changes relative to the onset of EEG seizures were determined by analyzing consecutive RR-interval changes in 10-minute recordings. We evaluated the correlation between the peri-ictal HR changes and the type of localization-related epilepsy. Results: Peri-ictal HR changes were documented in 70.2% (66/94) of all seizures, of which 62 were tachycardia (66.0%)and 4 were bradycardia (4.3%). Peri-ictal tachycardia occurred significantly with seizures as an ictal manifestation, more often in seizures with a right hemispheric onset than in those with a left hemispheric onset (77.4% vs. 50%, p=0.016). Peri-ictal HR changes were observed much earlier in seizures of mesial temporal lobe epilepsy (TLE) than in those of extratemporal lobe epilepsy (–54.4 s vs. –6.7 s, p<0.001). Conclusions: Peri-ictal HR changes were observed in 70.2% of seizures, 94% of which were tachycardia. These changes could be helpful in predicting seizure onset, especially in mesial TLE.

Introduction of Electrocardiography

노태호,장성원 대한부정맥학회 2017 International Journal of Arrhythmia Vol.18 No.2

In 1901, in a historic first, Willem Einthoven invented electrocardiography using a string galvanometer. He assigned the letters P, Q, R, S, and T to the major deflections and described electrocardiographic features of a number of cardiovascular disorders. Water pots that he initially used to record electrical signals from the skin were replaced with patchy electrodes later. These electrodes detect tiny electrical currents arising from the heart muscle during cardiac cycles. The tiny currents are amplified, filtered, and displayed to produce electrocardiographic recordings. The P wave is generated by depolarization of atria. The PR interval represents the duration of atrioventricular conduction, the QRS complex is produced by depolarization of both ventricles, and the ST-T wave reflects ventricular repolarization. Electrocardiography is essential to diagnose myocardial ischemia and various rhythm disorders. It has expanded its scope to include long-term monitoring, exercise tests, signal averaged electrocardiography, electrophysiologic studies, and three-dimensional electrocardiographic mapping system. Owing to these advances, electrocardiography now plays a critical role not only in diagnosis but also in the therapeutic fields of cardiac disease.

Electrocardiography Patterns and the Role of the Electrocardiography Score for Risk Stratification in Acute Pulmonary Embolism

류현민,이주환,권용섭,이상혁,배명환,이장훈,양동헌,박헌식,조용근,채성철,전재은,박의현 대한심장학회 2010 Korean Circulation Journal Vol.40 No.10

Background and Objectives: Data on the usefulness of a combination of different electrocardiography (ECG) abnormalities in risk stratification of patients with acute pulmonary embolism (PE) are limited. We thus investigated 12-lead ECG patterns in acute PE to evaluate the role of the ECG score in risk stratification of patients with acute PE. Subjects and Methods: One hundred twenty-five consecutive patients (63±14 years, 56 men) with acute PE who were admitted to Kyungpook National University Hospital between November 2001 and January 2008 were included. We analyzed ECG patterns and calculated the ECG score in all patients. We evaluated right ventricular systolic pressure (RVSP) (n=75) and RV hypokinesia (n= 80) using echocardiography for risk stratification of acute PE patients. Results: Among several ECG findings, sinus tachycardia and inverted T waves in V1-4 (39%) were observed most frequently. The mean ECG score and RVSP were 7.36±6.32 and 49±21 mmHg, respectively. The ECG score correlated with RVSP (r=0.277, p=0.016). The patients were divided into two groups {high ECG-score group (n=38): ECG score >12 and low ECG-score group (n=87): ECG score ≤12} based on the ECG score, with the maximum area under the curve. RV hypokinesia was observed more frequently in the high ECG-score group than in the low ECG-score group (p=0.006). Multivariate analysis revealed that a high ECG score was an independent predictor of high RVSP and RV hypokinesia. Conclusion: Sinus tachycardia and inverted T waves in V1-4 were commonly observed in acute PE. Moreover, the ECG score is a useful tool in risk stratification of patients with acute PE.

Study on Reusable Electrodes for Personal Electrocardiography

( Jonghoon Kim ),( Gilwon Yoon ) 한국센서학회 2018 센서학회지 Vol.27 No.5

Electrodes are an important part of electrocardiography (ECG); disposable electrodes have been extensively used. However, personal ECG monitoring devices for Internet of Things applications require reusable electrodes. As there have been no systematic studies on the characteristics of reusable electrodes to date, we conducted this study to assess the performance and feasibility of electrodes with different materials. We built reusable electrodes using twelve different metallic materials, including commonly used copper, silver, zinc, plating materials, chemically inert titanium, stainless steel, and aluminum. Each electrode was fabricated to a size of 5 × 10 mm. Their characteristics such as offset, baseline drift, stabilization time, and chemical inertness were compared. A personal ECG monitoring system was used to test the manufactured electrodes. The performances of the Ag, Cu, and Zn electrodes were better than the performances of other electrodes. However, these materials may not be used owing to the chemical changes that occur when the electrodes are in contact with the skin, such as discoloration and corrosion, which deteriorate their electrical characteristics. Titanium, stainless steel, and aluminum are chemically stable. The titanium electrode showed the best performance among the three, and it is our recommendation as a material for manufacturing reusable electrodes.

Prognostic Significance of the Lown Grades and Late Potentials in Patients after Myocardial Infarction

이진배,이영수,홍승표,김소연,김무곤,류재근,최지용,김기식,장성국 대한심장학회 2008 Korean Circulation Journal Vol.38 No.1

Background and Objectives: The aims of this study were to assess the long term overall survival of patients after an acute myocardial infarction (AMI), and to determine the association of survival with the occurrence of ventricular arrhythmia, as recorded by Holter electrocardiography (ECG) and signal-averaged electrocardiography (SAECG). Subjects and Methods: One hundred fifty two patients with an AMI were enrolled between January 2000 and August 2006. SAECG and Holter ECG were performed before hospital discharge (at range of 2-10 day). The grading system of Lown was used to evaluate the ventricular premature beats on Holter ECG. Three groups of patients were identified based on the seriousness of the ventricular arrhythmia, as identified by the Holter ECG: Lown grade 0, Lown grades 1, 2 and Lown grades 3, 4, 5. SAECG was performed with a high pass frequency of 25 Hz and 40 Hz. The presence of late potentials (LPs) recorded on SAECG was evaluated. The predictors for survival were assessed using Cox's proportional hazard model and Kaplan-Meier analysis. Results: The mean duration of follow-up was 45.8±25.5 months. Twenty four patients (15.8%) died during follow-up. The multivariate predictors of all cause death included age [hazard ratio (HR)=1.25, 95% confidence interval (CI)=1.08-1.47, p=0.003] and Lown grades 3, 4 and 5 (HR=19.17, 95% CI=1.25-290.80, p=0.034). Survival analysis did not show a significant relationship between LPs and overall patient survival. The only predictors for overall mortality were age and the Lown grade. Conclusion: SAECG did not predict mortality for the patient with AMI. The ventricular arrhythmias recorded by conventional Holter before hospital discharge may be a useful noninvasive prognostic test after an AMI. (Korean Circ J 2008;38:17-22)

기술수용모델을 활용한 스마트워치의 심전도와 광혈류 측정에 관한 연구

원미홍(Mi-Hong Won) 글로벌융합연구학회 2023 글로벌융합연구학회지 Vol.2 No.2

스마트워치는 손목에 장착되므로 헬스케어를 위한 장착 위치에 강력한 이점이 있다. 이러한 특성으로 인해 스마트워치는 오늘날의 건강 관리 및 기타 애플리케이션 시장에서 큰 기회를 얻고 있다. 본 연구의 목적은 스마트워치를 이용한 심전도(Electrocardiography : ECG) 및 광혈류측정(Photoplethysmography : PPG)의 사용 의도를 검증하기 위해, 기술수용이론(Technology Acceptance Model : TAM)의 매개 효과를 도입하였다. 논문모형은 안전성, 편의성, 정서적 신뢰 및 인지된 신뢰가 TAM을 매개로 사용 의도에 영향을 주는 것이다. 연구를 위해 네이버의 온라인 설문조사를 통해 340개의 샘플을 수집했으며, 331명의 응답자를 대상으로 가설검증을 시행하였다. 설문 결과는 구조방정식 모델링 기법의 소프트웨어 SmartPLS 4.0을 사용하였다. 논문의 결과는 스마트워치 ECG 및 PPG 애플리케이션의 사용을 확실하게 나타낸다. 연구의 결과는 다음과 같다. 안전성, 편의성, 인지적 신뢰는 지각된 유용성에 긍정적인 영향을 준다. 안전성, 편리성과 인지된 신뢰는 지각된 사용 용이성에 영향을 준다. 연구를 통한 실증적 결과는 새로운 정보를 제공하는 스마트워치 ECG 및 PPG 애플리케이션을 지속적인 사용자에게 의사결정 과정에 영향을 준다. 본 연구 결과는 사용자의 사용 의도를 더 잘 이해하기 위해 소비자의 안전성, 편의성 및 인지적 믿음 등을 고려할 필요가 있음을 보여준다. Since smartwatches are mounted on the wrist, there is a strong advantage in mounting positions for healthcare. These characteristics create great opportunities for smartwatches in today's healthcare and other application markets. The purpose of this study was to introduce the mediating effect of the Technology Acceptance Model (TAM) to verify the intention to use an electrocardiography (ECG) and a photoplethysmography (PPG) using a smartwatch. The thesis model is that safety, convenience, affective Trust, and perceived trust influence intention to use through TAM. 340 samples were collected through Naver's online survey for the study, and hypothesis testing was conducted on 331 respondents. The survey results were obtained using SmartPLS 4.0, a software for structural equation modeling technique. The results of the paper clearly indicate the use of smartwatch ECG and PPG applications. The results of the study are as follows. Safety, Convenience, and Cognitive trust have a positive effect on perceived usefulness. Safety, convenience and perceived trust influence perceived ease of use. The empirical results of the research influence the decision-making process for users who want to continuously use smartwatch ECG and PPG applications that provide new information. The results of this study show that it is necessary to consider consumer safety, convenience, and cognitive beliefs to better understand the user's intention to use.