Background and Objectives: Inherited arrhythmia (IA) is a more common cause of sudden cardiac death in Asian population, but little is known about the genetic background of Asian IA probands. We aimed to investigate the clinical characteristics and analyze the genetic underpinnings of IA in a Korean cohort. Methods: This study was conducted in a multicenter cohort of the Korean IA Registry from 2014 to 2017. Genetic testing was performed using a next-generation sequencing panel including 174 causative genes of cardiovascular disease. Results: Among the 265 IA probands, idiopathic ventricular fibrillation (IVF) and Brugada Syndrome (BrS) was the most prevalent diseases (96 and 95 cases respectively), followed by long QT syndrome (LQTS, n=54). Two-hundred-sixteen probands underwent genetic testing, and 69 probands (31.9%) were detected with genetic variant, with yield of pathogenic or likely pathogenic variant as 6.4%. Left ventricular ejection fraction was significantly lower in genotype positive probands (54.7±11.3 vs. 59.3±9.2%, p=0.005). IVF probands showed highest yield of positive genotype (54.0%), followed by LQTS (23.8%), and BrS (19.5%). Conclusions There were significant differences in clinical characteristics and genetic yields among BrS, LQTS, and IVF. Genetic testing did not provide better yield for BrS and LQTS. On the other hand, in IVF, genetic testing using multiple gene panel might enable the molecular diagnosis of concealed genotype, which may alter future clinical diagnosis and management strategies.

BACKGROUND: Vitamin K antagonist (VKA) to prevent thromboembolism in non-valvular atrial fibrillation (NVAF) patients has limitations such as drug interaction. This study investigated the clinical characteristics of Korean patients treated with VKA for stroke prevention and assessed quality of VKA therapy and treatment satisfaction. METHODS: We conducted a multicenter, prospective, non-interventional study. Patients with CHADS2 ≥ 1 and treated with VKA (started within the last 3 months) were enrolled from April 2013 to March 2014. Demographic and clinical features including risk factors of stroke and VKA treatment information was collected at baseline. Treatment patterns and international normalized ratio (INR) level were evaluated during follow-up. Time in therapeutic range (TTR) > 60% indicated well-controlled INR. Treatment satisfaction on the VKA use was measured by Treatment Satisfaction Questionnaire for Medication (TSQM) after 3 months of follow-up. RESULTS: A total of 877 patients (age, 67; male, 60%) were enrolled and followed up for one year. More than half of patients (56%) had CHADS2 ≥ 2 and 83.6% had CHA2DS2-VASc ≥ 2. A total of 852 patients had one or more INR measurement during their follow-up period. Among those patients, 25.5% discontinued VKA treatment during follow-up. Of all patients, 626 patients (73%) had poor-controlled INR (TTR < 60%) measure. Patients' treatment satisfaction measured with TSQM was 55.6 in global satisfaction domain. CONCLUSION: INR was poorly controlled in Korean NVAF patients treated with VKA. VKA users also showed low treatment satisfaction.
Atrial Fibrillation* ; Drug Interactions ; Follow-Up Studies ; Humans ; International Normalized Ratio ; Male ; Prospective Studies ; Risk Factors ; Stroke ; Thromboembolism ; Vitamin K* ; Vitamins*

The Beijing family of Mycobacterium tuberculosis has been emerging in the world. However, there are few nationwide data of genotypic distribution in Korea. This study aimed to identify the genotypic diversity of clinical isolates of M. tuberculosis and to demonstrate the population of Beijing family in Korea. We collected 96 clinical M. tuberculosis isolates from 11 university hospitals nationwide in Korea from 2008 to 2009. We observed 24 clusters in IS6110-RFLP analysis and 19 patterns in spoligotyping. Seventy-five isolates were confirmed to be Beijing family. Two isolates of the K strain and 12 isolates of the K family strain were also found. We found that drug resistance phenotypes were more strongly associated with Beijing family than non-Beijing family (P=0.003). This study gives an overview of the distribution of genotypes of M. tuberculosis in Korea. These findings indicate that we have to pay more attention to control of M. tuberculosis strains associated with the Beijing family.
Drug Resistance, Bacterial ; Genotype ; Humans ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis/*classification/genetics/isolation & purification ; Phenotype ; Polymorphism, Restriction Fragment Length ; Republic of Korea ; Tuberculosis/*epidemiology/genetics/microbiology

BACKGROUND: The Korean Medical Association intends to determine the relative value of physician's work separately from the total relative value scale for each medical or surgical procedure. This study was designed by the Korean Society for Laboratory Medicine to determine the relative value of laboratory physician's work (LPW) in each diagnostic test. The LPW was clearly defined first and then its relative value was measured quantitatively on the basis of time and intensity of work. METHODS: LPW in the laboratory test was categorized into three parts, pre-service, intra-service, and post-service. The relative value of physician's work was measured using Rasch paired comparisons. RESULTS: Practice characteristics of LPW were clearly defined according to the pre-service, intraservice, and post-service. However, any laboratory physician's effort to improve the quality of laboratory work, which could not be measured in each test, had to be comprised in a pre-service designated separately as `comprehensive pre-service'. Rasch analysis based on the rating survey for LPW taken by a diverse group of laboratory medicine and other medical specialists revealed higher values than those assigned previously in many routine diagnostic tests (e.g., Gram stain, hemoglobin, anti-HBs, ABO cell type). The results obtained by applying Rasch regression analysis showed that the diagnostic tests that had been given a low relative value of LPW tended to be measured with more improved relative valuation. CONCLUSIONS: LPW for quality control and quality improvement was acknowledged with an improved relative valuation, even in the routine diagnostic test, as the results of Rasch analysis based on the rating survey. LPW might be further equated across the specialties, considering the practice characteristics of LPW.
Diagnostic Tests, Routine ; Matched-Pair Analysis ; Quality Control ; Quality Improvement ; Relative Value Scales ; Specialization

BACKGROUND AND OBJECTIVES: The mechanism by which atrial fibrillation (AF) electrically converts to sinus rhythm remains undefined. The purpose of this study was to assess in detail the electrograms recorded during cardioversion using direct current (DC) shock. SUBJECTS AND METHODS: In 23 patients with AF (chronic n=20, paroxysmal n=3, M:F=15:8, 50 - 70 years old), electrograms were recorded simultaneously from a 20-pole electrode catheters (Duo-deca, DAIG) in the right atrial free wall and the coronary sinus immediately after DC shock given transthoracically. The activation patterns following 45 trials consisting of 23 successful and 22 unsuccessful cardioversion were analyzed. RESULTS: Two distinct patterns following successful cardioversion were observed; either immediate resumption of normal sinus rhythm (n=5, 21%), or one or two activations immediately after shock preceded normal sinus rhythm (n=18, 79%). The energy levels of the two patterns were not significantly different (260 J, 250 J, respectively). Four patterns following unsuccessful cardioversion were noted; unchanged (n=10, 45%), converted to atrial flutter (n=4, 18%), production of three or four beats of more coordinated complexes and reverted to AF (n=5, 22%), and converted to sinus rhythm transiently and reinitiated AF by one or two atrial premature beats (n=3, 13%). The magnitude of the DC shock applied at these 4 different patterns was 196 J, 240 J, 264 J, and 340 J, respectively in which low energy levels made a simultaneous depolarization of the entire atria unlikely. CONCLUSION: Distinct activation patterns were identified following successful and unsuccessful cardioversion using DC shock for AF. These observations suggest that total depolarization of the entire atria is not a prerequisite for the conversion of AF into sinus rhythm.
Atrial Fibrillation* ; Atrial Flutter ; Cardiac Complexes, Premature ; Catheters ; Coronary Sinus ; Electric Countershock* ; Electrodes ; Humans ; Shock

No abstract available.

BACKGROUND AND OBJECTIVES: To evaluate the association between chronic infection with Chlamydia pneumoniae, as measured by Immunoglobulin G and A, and acute myocardial infarction (AMI) in Korea. MATERIALS AND METHODS: A total of 136 patients [normal control 65 cases (male:female 27:8, mean age 55.1+/-11.7 years), AMI 71 cases (male:female 54:17, mean age 58.9+/-12.7 years)] had immunoglobulin G, A, and M antibody titers measured against Chlamydia pneumoniae by microimmunoflorescence assay and had coronary angiography performed. We investigated the incidence of major adverse cardiac events (MACE) at 6 month follow-up. Controls were defined as patients with no significant stenosis on coronary angiography. RESULTS: 1) AMI patients were more likely to be male (76.1: 41.5%) and smokers (67.6: 16.9%) compared with the controls. >2) In AMI patients, there was a weak correlation with IgG and IgA antibody titers (r=0.39, p=0.001).> 3) After adjusting for gender and smoking status, IgG and IgA antibody titers were similar between two groups.> 4) Increased IgG and IgA titers did not affect the MACE during follow-up. CONCLUSION: Chronic Chlamydia pneumoniae infection detected by immunoglobulin assay is not significantly associated with AMI. Further studies, such as polymerase chain reaction, immunocytochemistry, or culture of the atheromatous plaques, are needed to better define the association.
Chlamydia* ; Chlamydophila pneumoniae* ; Constriction, Pathologic ; Coronary Angiography ; Follow-Up Studies ; Humans ; Immunoglobulin A ; Immunoglobulin G ; Immunoglobulins ; Immunohistochemistry ; Incidence ; Korea* ; Male ; Myocardial Infarction* ; Plaque, Atherosclerotic ; Polymerase Chain Reaction ; Risk Factors* ; Smoke ; Smoking

BACKGROUND AND OBJECTIVES: Myocardial infarction in young age is an uncommon condition and has few risk factors than old aged group. Hyperhomocysteinemia, which is an independent risk factor for vascular disease, is associated with myocardial infarction (MI). Therefore, we evaluate that hyperhomocysteinemia is associated with myocardial infaction in young age. MATERIALS AND METHODS: A total 64 patients [normal control 23 (young:old 13:10 mean age 54.2+/-13.8), M.I 41 (young:old=13:28 mean age 53.9+/-14.1)] measured plasma levels of total homocysteine, folate, vitamine B6, and vitamine B12 and performed coronary angiography and echocardiography. Young aged group was defined male <45 years old and premenopausal wemen. RESULTS: 1) Homocysteine concentration was higher in MI patients than in controls (control 6.35+/-1.7 mmol/L, MI 11.3+/-4.9 mmol/L, p<0.001). 2) Levels of homocysteine were not significantly correlated with vitamine B6, B12, and folate, but were correlated with vitamine B12 in myocardial infarction (r=0.388, p<0.001). 3) Homocysteine levels were correlated with age, apoprotein B, BUN (r=0.374 0.52, p=0.05, 0.689 p=0.001) but correlated inversely with gobal function (r= - 0.672, p=0.001). 4) After adjusting for age factor in MI patients, homocysteine concentration was not significantly higher in young aged than in old aged group (young age 6.78+/-2.07, old age 10.2+/-4.17 mmol/L p=0.351 by ANCOVA). CONCLUSION: Hyperhomocysteinemia is an independent risk factor of MI, but is not clear association with MI in young age.
Age Factors ; Apoproteins ; Coronary Angiography ; Echocardiography ; Folic Acid* ; Homocysteine* ; Humans ; Hyperhomocysteinemia ; Male ; Myocardial Infarction* ; Plasma* ; Risk Factors ; Vascular Diseases ; Vitamins*

BACKGROUND AND OBJECTIVES: To reduce the subacute stent thrombosis, the use of high pressure final balloon dilatations and confirmation of adequate stent expansion by intravascular ultrasound has been recommended. The purpose of this study is to compare incidence of stent thrombosis and major cardiac events (MACE) between high and moderate pressure balloon technique without using intravascular ultrasound (IVUS) guidance. MATERIALS AND METHODS: We prospectively studied 147 patients (110 males & 37 females, mean;56.9+/-9.9 years, 154 lesions) who were deployed intracoronary stents with the use of conventional technique except IVUS guidance. According to inflation pressure, patients were divided into two groups; G1 (moderate pressure group, maximum inflation balloon pressure <14ATM, 77 lesion) & G2 (high pressure group, maximum inflation balloon pressure > or =14ATM, 77 lesions). We investigated the incidence of stent thrombosis and MACE between two groups during the 10 month follow up examination. RESULTS: 1) The mean inflation presure is different between two groups by definition (G1:G2 10.2+/-1.8; 15.2+/-1.3 ATM p<0.001). 2) The stenotic lesion lengths of the group of patients treated with the moderate pressure techique were longer than those treated under the high pressure technique (G1:G2 19.8+/-7.1 mm; 16.3+/-4.1 mm p=0.002). 3) There were no significant differences between the moderate pressure group and the high pressure group during the 10 month follow-up examination in terms of MACE[early event (0-14D)-subacute thrombosis G1:G2 0:0 death G1; G2 1:1/late events (15D - 10M)-repeat revascularization:G1; G2 8; 7, CABG G1; G2 1; 0, Q.M.I G1; G2 1; 0]. CONCLUSION: Onselectedpatients,itispossibletoconsidermoderatepressure technique as an other option for coronary stenting.
Dilatation ; Female ; Follow-Up Studies ; Humans ; Incidence ; Inflation, Economic* ; Male ; Prospective Studies ; Stents* ; Thrombosis ; Ultrasonography

BACKGROUND: The 3 minutes increment of dobutamine dose protocol is most commonly used method in dobutamine stress echocardiography (DSE). But the precise hemodynamic response to dobutamine dosage and its difference by extending stage duration have not been well elucidated. MATERIALS AND METHOD: Nineteen healthy voluntary subjects with a mean age of 23.9+/-4.7 years were included. All subjects underwent 3-minutes incremental and 5-minnutes incremental protocol of DSE at random order in a same day. Heart rate, blood pressure, stroke volume, fractional shortening, rate-pressure product and cardiac output were measured every 3 minutes in 3-min protocol of DSE. In 5-min protocol, same variables were measured at 3 minutes of each stage as well as at 5 minutes. RESULTS: 1) Heart rate did not increase until 10 microgram/kg/min dose and increased thereafter by increment of dobutamine dose. 2) Fractional shortening and stroke volume increased markedly from the 5 microgram/kg/min until 20 microgram/kg/min dose and showed slow increase or plateau at a higher dobutamine dose. 3) Systolic blood pressure, cardiac output and rate-pressure product increased continuously from initial dose to maximal dose. 4) Although by extending stage duration to 5 minute in 5-min protocol produced greater hemodynamic effects than those measured at 3 minutes of each stage, there were no significant difference in the results of 3-min and 5-min protocol of DSE. CONCLUSION: The increase of cardiac contractility most contributed to increase of cardiac output until 20microgram/kg/min dose and the increase of herat rate contributed dominantly thereafter, thus the hemodynamic variables showed different responses to increment of dobutamine dose. There were no significant difference in hemodynamic effects between the two protocols. So it is considered that 3-min protocol of DSE gives similar hemodynamic information as 5-min protocol and is more time-saving method.
Blood Pressure ; Cardiac Output ; Dobutamine* ; Echocardiography, Stress* ; Heart Rate ; Hemodynamics* ; Stroke Volume