• Journal of Yeungnam Medical Science
• /
• v.6 no.1
• /
• pp.99-107
• /
• 1989

24-hour ambulatory ECG monitoring has been examined for the evaluation of heart rate and longest pause in 34 patients with chronic atrial fibrillation(20 patients treated with digoxin and 14 patients without treatment). Following results were obtained : 1. In 34 patients, the mean of average heart rates was $75.7{\pm}13.8$/minute, fastest heart rates $148.0{\pm}32.4$/minute, slowest heart rates $48.1{\pm}8.4$/minute, difference between fastest and slowest heart rates in individual patients $99.9{\pm}29.0$/minute and longest pauses $2.95{\pm}1.06$seconds. The longest pauses of more than 4.0 seconds occurred in 4 of the 34 patients and made an exeption of comparison groups. 2. In 27 of the 34 patients, ventricular premature contractures were developed and in 11 of 27, mainly occured less than 100/24 hours and aberrant conduction occurred in all patients. 3. In 20 patients treated with digoxin(0.25mg/day), the mean of average heart rates was $78.4{\pm}13.7$/minute, fastest heart rates $152.5{\pm}33.1$/minute, slowest heart rates $48.9{\pm}8.5$/minute, difference between fastest and slowest heart rates in individual patients $103.6{\pm}31.7$/minute and longest pauses $2.55{\pm}0.50$seconds. 4. In 10 patients without treatment, the mean of average heart rates was $78.0{\pm}10.7$/minute, fastest heart rates $154.5{\pm}26.8$/minute, slowest heart rates $50.6{\pm}7.1$/minute, difference between fastest and slowest heart rates in individual patients $103.9{\pm}22.2$/minute and longest pauses $2.66{\pm}0.39$seconds. 5. The difference of heart rates and longest pauses between patients with treatment and without treatment were statistically not significant(P>0.05). In summary, authors seemed to consider that 24-hour ambulatory ECG was useful and safe method for clinical evaluation of patients with chronic atrial fibrillation.

• Clinical and Experimental Pediatrics
• /
• v.56 no.7
• /
• pp.308-311
• /
• 2013

In this report, we present a pediatric case of severe symptomatic hypermagnesemia resulting from the use of magnesium oxide as a laxative in a child undergoing continuous cyclic peritoneal dialysis for end-stage renal disease. The patient showed abnormal electrocardiography (ECG) findings, such as tall T waves, a widened QRS complex, and irregular conduction, which were initially misdiagnosed as hyperkalemia; later, the correct diagnosis of hypermagnesemia was obtained. Emergent hemodialysis successfully returned the serum magnesium concentration to normal without complications. When abnormal ECG changes are detected in patients with renal failure, hypermagnesemia should be considered.

• Journal of Biomedical Engineering Research
• /
• v.29 no.2
• /
• pp.164-171
• /
• 2008

Recently, many of hospitals have hurried to computerize the resulting data from medical devices, in order to introduce Electric Medical Record(EMR). In terms of the linkage between medical devices and hospital information systems, however, many difficulties have arisen due to some reasons such as the variety of prescription input, the format difference of the resulting data sheet, and the interface difference between medical devices from different companies. To solve these problems, many researches on standardization of the resulting data of medical devices have been performed. In this study, the linkage between hospital information systems and resulting datum in Electrocardiogram(ECG) generating biosignal waveform was tested by applying Medical waveform Format Encoding Rules(MFER) Version 1.02, which has more advantages than existing global standard. MFER viewer, in addition, was made to display the resulting data on a screen. The MFER viewer was tested and compared to the existing Scalable Vector Graphics (SVG) Viewer. The results showed that this method is more effective in the interface the data storage and application, because of simplicity and easiness in data applications. And the results show that the MFER is convenience and effective for physician. It is considered that the role of MFER as the interface in biosignal waveform including Electrocardiogram medical devices would expand in the near future.

• Journal of Biomedical Engineering Research
• /
• v.39 no.2
• /
• pp.87-93
• /
• 2018

The measurement of Heart Rate Variability (HRV) using electrocardiogram (ECG) signals has been used to predict fatigue and stress levels in a clinical environment, yet, owing to the complexity of such ECG systems, a domestic, nonclinical monitoring of HRV has not been a practical possibility. Recently though, Pulse Rate Variability (PRV) has been studied as an alternative to HRV. In this study, we investigated the reliability of measuring PRV by means of a smartwatch. The PRV results were compared to HRV results in similar test conditions, i.e. those obtained under rapid and deep-breathing scenarios. From the results obtained, it transpires that the Bland-Altman ratio and cross-correlation coefficients between several PRV and HRV parameters were highly correlated, thus suggesting that the results of measuring PRV using a smartwatch can be used to predict HRV in nonclinical environments.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.10
• /
• pp.131-136
• /
• 2007

In this paper, we estimated the effects of different color stimulation on the cognitive function of human quantitatively. For the stimulations we used color lights with 6 color filters such as red, yellow, green, blue, violet and white. The experiment was performed in a soundproof chamber. 50 young male and female subjects were participated in the experiment. To find the appropriate color cognitive function, the endogenous visuospatial attention task(EVAT) and one back working memory task(OWMT) were performed. The reaction time and accuracy degree were measured. The results showed that the reaction time of EVAT was the fastest and the accuracy degree of attention task was the highest in green environment. The reaction time of OWMT was the fastest in yellow and the accuracy degree of memory task was the highest in blue. For physiological parameters, we measured electrocardiogram(ECG) and HRV spectrum analysis, HF/LF color environment. These results can be used as an indicator in the design of color environment and clinical applications.

• Clinical and Experimental Pediatrics
• /
• v.59 no.sup1
• /
• pp.129-132
• /
• 2016

Ictal tachycardia and bradycardia are common arrhythmias; however, ictal sinus pause and asystole are rare. Ictal arrhythmia is mostly reported in adults with temporal lobe epilepsy. Recently, ictal arrhythmia was recognized as a major warning sign of sudden unexpected death in epilepsy. We present an interesting case of a child with ictal sinus pause and asystole. A 27-month-old girl was hospitalized due to 5 episodes of convulsions during the past 2 days. Results of routine electroencephalography (EEG) were normal, but she experienced brief generalized tonic seizure for 3 days. During video-monitored EEG and echocardiography (ECG), she showed multiple myoclonic seizures simultaneously or independently, as well as frequent sinus pauses. After treatment with valproic acid, myoclonus and generalized tonic seizures were well controlled and only 2 sinus pauses were seen on 24-hour Holter ECG monitoring. Sinus dysfunction should be recognized on EEG, and it can sometimes be treated successfully with only antiepileptic medication.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.3
• /
• pp.493-498
• /
• 2016

Heart Rate Variability (HRV) represents beat-to-beat fluctuations of R-R intervals in Electrocardiogram (ECG). On of the clinical applications of HRV is to assess the mental-stress state by evaluating its power spectral density distribution. This study aims at finding new discriminative role of the coupled-oscillating coupling constants, Cs and Cp in the Integral Pulse Frequency Modulation (IPFM) model. Based on comparing with power spectral density of HRV in terms of the relative ratio of the low and high-frequency power component, we can conclude the fact that the coupling parameters Cs and Cp can replace the role of HRV power spectrum interpretation for judging the mental-stress state.

• Journal of Chest Surgery
• /
• v.19 no.1
• /
• pp.25-34
• /
• 1986

Recently, radionuclide angiocardiogram is one of the most common procedure for assessment of ventricular performance due to its distinctive advantages such as safety, accuracy, and ease of repeated studies. Also, measurement and comparison between pre and postoperative left ventricular ejection fraction [LVEF] are meaningful for assessing the severity of myocardial damage which occurred during open heart surgery and the status of myocardial recovery. We obtained pre and post operative LVEF using radionuclide angiocardiogram on 30 patients composed of atrial septal defect, ventricular septal defect, cyanotic congenital heart disease, and valvular heart disease who undergone the open heart surgery from March to august 1984. The study revealed that ventricular septal defect and mitral valvular heart disease showed 8.1% and 6.2% decreases of postoperative LVEF, respectively. But, there are little increases of postoperative LVEF in the atrial septal defect and cyanotic congenital heart disease. In ventricular septal defect, each group of Qp/Qs over 2.0 and systolic pulmonary artery pressure over 50mmHg showed significant 17% and 14.7% decreases of postoperative LVEF, respectively. Considering the duration of the aortic cross clamping times and closing methods of VSD, each group of duration over 30 min. and of patch closure showed 13.9% and 14.2% decreases of LVEF between pre and postoperative status respectively which was significant finding statistically.

• Clinical and Experimental Pediatrics
• /
• v.64 no.11
• /
• pp.582-587
• /
• 2021

Background: Syncope is a common problem in children and adolescents. However, a large proportion of syncope cases have no underlying cause. Purpose: This study aimed to identify the factors affecting the severity of syncope using tissue Doppler imaging (TDI). Methods: This retrospective study included 61 children and adolescents with syncope who underwent echocardiography. The head-up-tilt test (HUT) was performed when there was a more severe syncopal event. We compared the echocardiographic findings between the execute HUT and nonexecute HUT, negative HUT result and positive HUT result, and normal electrocardiogram (ECG) and abnormal ECG groups. Data were analyzed using an unpaired t test post hoc analysis. Results: In the execute and nonexecute HUT groups, the odds ratios were 0.55 for medial E/E' (P=0.040) and 0.64 for lateral E/E' (P=0.049). Comparison of the results of the decreased, normal, and increased groups for lateral E/E' revealed a significant difference in the execution HUT and nonexecute HUT groups (overall, P=0.004; decreased vs. increased, P=0.003; normal vs. increased, P=0.050). Conclusion: Medial E/E' and lateral E/E' were decreased in patients with severe syncopal events. These findings suggest that the presence of left ventricular diastolic deterioration may cause hypoperfusion even in the absence of organic causes and, consequently, increase syncope severity and frequency. The TDI measured by echocardiography can be used as an index to predict syncope recurrence and/or severity.

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