• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.2021-2030
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• 2012

Premature ventricular contraction(PVC) is the most common disease among arrhythmia and it may cause serious situations such as ventricular fibrillation and ventricular tachycardia. Particularly, in the healthcare system that must continuously monitor patient's situation, it is necessary to process ECG (Electrocardiography) signal in realtime. In other words, the design of algorithm that exactly detects R wave using minimal computation and classifies PVC by analyzing the persons's physical condition and/or environment is needed. Thus, the patient adaptive pattern matching algorithm for the classification of PVC is presented in this paper. For this purpose, we detected R wave through the preprocessing method, adaptive threshold and window. Also, we applied pattern matching method to classify each patient's normal cardiac behavior through the Hash function. The performance of R wave detection and abnormal beat classification is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.33% in R wave detection and the rate of 0.32% in abnormal beat classification error.

• Korean Circulation Journal
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• v.48 no.12
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• pp.1081-1096
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• 2018

We reviewed the anatomical characteristics of the conduction system in the ventricles of human and ungulate hearts and then raised some questions to be answered by clinical and anatomical studies in the future. The ventricular conduction system is a 3-dimensional structure as compared to the 2-dimensional character of the atrial conduction system. The proximal part consisting of the atrioventricular node, the bundle of His and fascicles are groups of conducting cells surrounded by fibrous connective tissue so as to insulate from the underlying myocardium. Their location and morphological characters are well established. The bundle of His is a cord like structure but the left and right fascicles are broad at the proximal and branching at the distal part. The more distal part of fascicles and Purkinje system are linear networks of conducting cells at the immediate subendocardium but the intra-mural network is detected at the inner half of the ventricular wall. The papillary muscle also harbors Purkinje system not in the deeper part. It is hard to recognize histologically in human hearts but conducting cells as well as Purkinje cells are easily recognized in ungulate hearts. Further observation on human and ungulate hearts with myocardial infarct, we could find preserved Purkinje system at the subendocardium in contrast to the damaged system at the deeper myocardium. Further studies are necessary on the anatomical characteristics of this peripheral conduction system so as to correlate the clinical data on hearts with ventricular arrhythmias.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.422-427
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• 1999

Background: Tachycardia induced heart failure model would be the model of choice for the dilated cardiomyopathy. This more closely resembles the clinical syndrome and does not require major surgical trauma, myocardial ischemia and pharmacological or toxic depression of cardiac function. When heart failure is progressive, application of new surgical procedures to the faling heart is highly risky. It has been shown that recovery trajectory from heart failure is a new method in decreasing animal mortality. The purpose is to establish the control datas for recovery trajectory in the canine heart failure model. Material and Method: 21 mongrel dogs were studied at 4 stages(baseline, at the heart failure, 4 and 8 weeks after recovery). Heart failure was induced during 4 weeks of continuous rapid pacing using a pacemaker. Eight weeks of trajectory of recovery period was allowed. Indices of left ventricular function and dimension were measured every 2 weeks and the hemodynamics were measured by use of Swan-Ganz catheterization and thermodilution method every 4 weeks. Values were expressed as mean${\pm}$standard deviation. Result: 4(20%) dogs died due to heart failure. Left ventricular end-diastolic volume at the 4 stages were 40.8${\pm}$7.4, 82.1${\pm}$21.1, 59.9${\pm}$7.7 and 46.5${\pm}$6.5ml. Left ventricular end-systolic volume showed the same trend. Ejection fractions were 50.6${\pm}$4.1, 17.5${\pm}$5.8, 36.3${\pm}$7.3, and 41.5${\pm}$2.4%. Blood pressure and heart rate showed no significant changes. Pressures of central vein, right ventricle, pulmonary artery, and pulmonary capillary wedge showed significant increase during the heart failure period, normalizing at the end of recovery period. Stroke volumes were 21.5${\pm}$8.2, 12.3${\pm}$3.5, 17.9${\pm}$4.6, and 15.5${\pm}$3.4ml. Blood norepinephrine level was 133.3${\pm}$60.0pg/dL at the baseline and 479.4${\pm}$327.3pg/dL at the heart failure stage(p=0.008). Conclusion: Development of tachycardia induced heart failure model is of high priority due to ready availability and reasonable amenability to measurements. Recovery trajectory after cessation of tachycardia showed reduction of cardiac dilatation and heart function. Application of new surgical procedures during the recovery period could decrease animal mortality.

• Neonatal Medicine
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• v.28 no.2
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• pp.77-82
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• 2021

We present the case of a healthy 28-day-old female full-term neonate who was admitted to the neonatal intensive care unit for severe metabolic acidosis, hypoglycemia, and an initial sinus rhythm. The first diagnostic hypothesis was hypovolemic shock, and fluid resuscitation was started immediately. During fluid therapy, cardiovascular collapse occurred with supraventricular tachycardia. The latter was successfully treated with adenosine and beta-blockers. After 8 days, electrocardiography showed ventricular pre-excitation, and Wolff-Parkinson-White syndrome was diagnosed. A novel variant of the MYL2 gene that is related to hypertrophic cardiomyopathy and conduction defect was found after discharge. Cardiogenic shock should be considered, despite being a rare cause of shock in neonates.

• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.125-129
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• 2013

Purpose: The use of implantable cardioverter defibrillators (ICDs) to prevent sudden cardiac death is increasing in children and adolescents. This study investigated the use of ICDs in children with congenital heart disease. Methods: This retrospective study was conducted on the clinical characteristics and effectiveness of ICD implantation at the department of pediatrics of a single tertiary center between 2007 and 2011. Results: Fifteen patients underwent ICD implantation. Their mean age at the time of implantation was $14.5{\pm}5.4$ years (range, 2 to 22 years). The follow-up duration was $28.9{\pm}20.4$ months. The cause of ICD implantation was cardiac arrest in 7, sustained ventricular tachycardia in 6, and syncope in 2 patients. The underlying disorders were as follows: ionic channelopathy in 6 patients (long QT type 3 in 4, catecholaminergic polymorphic ventricular tachycardia [CPVT] in 1, and J wave syndrome in 1), cardiomyopathy in 5 patients, and postoperative congenital heart disease in 4 patients. ICD coils were implanted in the pericardial space in 2 children (ages 2 and 6 years). Five patients received appropriate ICD shock therapy, and 2 patients received inappropriate shocks due to supraventricular tachycardia. During follow-up, 2 patients required lead dysfunction-related revision. One patient with CPVT suffered from an ICD storm that was resolved using sympathetic denervation surgery. Conclusion: The overall ICD outcome was acceptable in most pediatric patients. Early diagnosis and timely ICD implantation are recommended for preventing sudden death in high-risk children and patients with congenital heart disease.

• The Korean Nurse
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• v.33 no.4
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• pp.62-85
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• 1994

The data were analyzed by using an S. P. S. S. computerized program for mean, standard deviation, percentage and paired t-test. The results of this study were as follows: 1. The increase in $PaO_2$ after hyperoxygenation and hyperinflation was highly statistically significant(p=0.041), and the increase in $PaO_2$ immediately after suctioning was not significant (p=0.752). The time of lowest $PaO_2$ was 30 seconds after the endotracheal suction. 2. The occurrance of cardiac arrhythmia after the endotracheal suction included sinus tachycardia, sinus arrhythmia, sinus bradycardia, premature atrial contraction (PAC), and premature ventricular contraction (PVC). The most frequent cardiac arrhythmia was sinus tachycardia (a subjects). Sinus arrhythmia was observed in 5 subjects and continued till 10 minutes after suctioning in two of these. Sinus bradycardia occurred in only 3 subjects and among them, 1 subjects shows sinus arrythmia till 10 minutes after suctioning along. PAC was observed in only one subject and continued till five minutes after suctining along with sinus arrhythmia. PVC was observed in three subjects: it lasted for only 30 seconds after suctioning in two subjects. but continued for 10 minutes after suctioning in the third. 6 subjects manifested two kinds of Cardiac arrhythmia Three of them showed sinus tachycardia with PVC, another 2 showed sinus bradycardia with sinus arrhythmia, and the other subject showed sinus arrhythmia with PAC. 3. The increases in heart rate during the endotracheal suction immediately after and at 30 seconds after suctioning were statistically significant (p=0.005). The increase in heart rate at one minute after suctioning was also significant (p=0.023). The increase in heart rate continued until 10 minutes after the endotracheal suction, but was not statistically significant In this study, endotracheal suctioning with hyperoxygenation and hyperinflation was effective in preventing a decrease in $PaO_2$ after suctioning, but not in preventing cardiac arrhythmias. Nurses should be aware of the complications of endotracheal suctioning and do effective hyperoxygenation and hyperinflation before and after suctioning. Further research is needed to develop a efficient endotracheal suction method which will minimize complications. This study needs to be replicated with different population of patients intubatted or having a tracheostomy, specifically, patients who cardiac or pulmonary desease. The data were analyzed by using an S. P. S. S. computerized program for mean, standard deviation, percentage and paired t-test. The results of this study were as follows: 1. The increase in $PaO_2$ after hyperoxygenation and hyperinflation was highly statistically significant(p=0.041), and the increase in $PaO_2$ immediately after suctioning was not significant (p=0.752). The time of lowest $PaO_2$ was 30 seconds after the endotracheal suction. 2. The occurrance of cardiac arrhythmia after the endotracheal suction included sinus tachycardia, sinus arrhythmia, sinus bradycardia, premature atrial contraction (PAC), and premature ventricular contraction (PVC). The most frequent cardiac arrhythmia was sinus tachycardia (a subjects). Sinus arrhythmia was observed in 5 subjects and continued till 10 minutes after suctioning in two of these. Sinus bradycardia occurred in only 3 subjects and among them, 1 subjects shows sinus arrythmia till 10 minutes after suctioning along. PAC was observed in only one subject and continued till five minutes after suctining along with sinus arrhythmia. PVC was observed in three subjects: it lasted for only 30 seconds after suctioning in two subjects. but continued for 10 minutes after suctioning in the third. 6 subjects manifested two kinds of Cardiac arrhythmia Three of them showed sinus tachycardia with PVC, another 2 showed sinus bradycardia with sinus arrhythmia, and the other subject showed sinus arrhythmia with PAC. 3. The increases in heart rate during the endotracheal suction immediately after and at 30 seconds after suctioning were statistically significant (p=0.005). The increase in heart rate at one minute after suctioning was also significant (p=0.023). The increase in heart rate continued until 10 minutes after the endotracheal suction, but was not statistically significant In this study, endotracheal suctioning with hyperoxygenation and hyperinflation was effective in preventing a decrease in $PaO_2$ after suctioning, but not in preventing cardiac arrhythmias. Nurses should be aware of the complications of endotracheal suctioning and do effective hyperoxygenation and hyperinflation before and after suctioning. Further research is needed to develop a efficient endotracheal suction method which will minimize complications. This study needs to be replicated with different population of patients intubatted or having a tracheostomy, specifically, patients who cardiac or pulmonary desease.

• Journal of Yeungnam Medical Science
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• v.4 no.2
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• pp.23-27
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• 1987

Mass electrocardiographic (ECG) examination was performed on 13,801 children (male 7,526 and female 6,275) of elementary and middle school in Taegu from May 1. 1986. to April 30. 1987. We read their ECG according to the "Pediatric Electrocardiography." The results were as following; The Incidence of ECG abnormality was 1.05%(male 1.3% and female 0.75%). Fifty eight children (0.42%) had atrial and ventricular hypertrophy; two right atrial hypertrophy, five left atrial hypertrophy, thirty five fight ventricular hypertrophy and sixteen left ventricular hypertrophy respectively. Ectopic beats occurred in 25 children (0.18%) ; They were atrial in 12 children, ventricular in 8 children and junctional in 5 children. There were 62 children (0.45%) of conduction disturbance ; They were first degree atrioventricular (A-V) block in 21 children, type I second degree A-V block in 1 child, A-V dissociation in 1 child, right bundle branch block in 36 children, left bundle branch block in 1 child and WPW syndrome in 2 children. Nonspecific ST, T changes and sinus tachycardia were found in 3 and one children respectively.

• Korean Journal of Clinical Pharmacy
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• v.6 no.2
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• pp.32-40
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• 1996

The electrophysiological effects of benzopyran potassium channel openers (PCOs: lemakalim, KR-30450 and KR-30818) on the ischemia/reperfusion-induced arrythmias were investigated. In anesthetized rats, subjected to 45 min occlusion of the left anterior descending coronary artery (LAD) followed by 90 min reperfusion, ventricular arrythmias were identified according to the Lambeth Conventions by lead II ECG. Rats were intravenously given vehicle ($1\%$ DMSO), lemakalim, KR-30450, and KR-30818 alone or in combination with a selective $K_{ATP}$ blocker glibenclamide, 30 min prior to coronary occlusion. Compared to vehicle, lemakalim ($30{\mu}g/kg$ i.v.), the active enantiomer of cromakalim, had a tendancy to increase the duration of ventricular tachycardia (Vl) and ventricular fibrillation (VF), the number of premature ventricular complexes (PVC) and the incidence of VF, especially in the early post-occlusion peroid ($0\~15$ min), while increasing ST-segment elevation. Both KR-30450 ($30{\mu}g/kg$, i.v.) and KR-30818 (30, $100{\mu}g/kg$, i.v.) showed similar proarrhythmic effects to lemakalim (PVC, duration of VT, and incidence of VF) with a tendancy to decrease the duration of VF and ST-segment elevation. Unlike other PCOs, however, glibenclamide (0.3, 1.0 mg/kg) had opposite effects on the induction of arrhythmias (PVC, the duration of VF); it had a tendancy to increase the duration of VT with a slight elevation of ST-segment. It seems likely that glibenclamide (0.3 mg/kg, i.v.), reduced the effects of lemakalim or KR-30450 ($30{\mu}g/kg$, i.v.) on arrhythmias (PVC, VT, VF and ST-segment). These results indicate that, in the coronary occluded rat model of ischemia, lemikuiln and KR-30450 exert a proarrhythmic activity, the effect being considered related to the opening of KATP channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1289-1295
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• 2009

Premature ventricular contractions are the most common of all arrhythmias and may cause more serious situation like ventricular fibrillation and ventricular tachycardia in some patients. Therefore, the detection of this arrhythmia becomes crucial in the early diagnosis and prevention of possible life threatening cardiac diseases. Particularly, in the healthcare system that must continuously monitor people's situation, it is necessary to process ECG signal in realtime. In other words, design of algorithm that exactly detects R wave using minimal computation and classifies PVC is needed. So, R wave detection algorithm based adaptive threshold and window for the classification of PVC is presented in this paper. For this purpose, ECG signals are first processed by the usual preprocessing method and R wave was detected and adaptive window through R-R interval is used for efficiency of the detection. The performance of R wave detection and PVC classification is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate 99.33%, 88.86% accuracy respectively for R wave detection and PVC classification.

• Journal of Veterinary Clinics
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• v.6 no.2
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• pp.281-290
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• 1989

To gain insight into the relationship between the occurrence of occlusive arrhythmia(OA) and the incidence of reperfusion arrhythmia(RA), this study used 25 open-chest dogs anesthetized with halothan, these were ligated between anterior ventricular branch and marginal branch of left circumflex artery for 30 minutes and occlusive arrhythmia were observed during the ligation. After releasing of the ligation, TA were observed during 5 minutes. The results were summerized as follow； 1. Such arrhythmias as ventricular fibrillation(VF), short run type VPC Premature contraction(VPC), Venticular tachycardia(VT), ventricularc and trigeminy VPC(TVPC) were observed during occlusion and reperfusion. 2. The cases occurred VT, SRVPC and TVPC during occlusion necessarily were Incidence of RA. 3. RA never occurred without appearence of occlusive arrhythmias. 4. The occurrence rate of OA showed 55.5% in the incidence group of RA and 24.6％ in the non incidence group of RA. 5. The occurrence rate of VPC during occlusion showed 9.9＋5.85(episode/min) in the incidence group of RA and 4.46＋5.88(episode/min) in the non-incidence group of RA. These results may be estimated that the occurrence of VT, SRVPC and TVPC, and the high occurrence rate of VPC during occlusion can be predicted the incidence.