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.

Purpose: We investigated the possible effects of diabetic ketoacidosis (DKA) at the initial diagnosis of type 1 diabetes mellitus (T1DM) on the clinical outcomes of pediatric patients. Methods: Medical records of children and adolescents with newly diagnosed T1DM seen in the Ajou University Hospital from January 2008 to August 2020 were reviewed and analyzed. Results: Among 129 diagnosed T1DM patients, 40.3% presented with DKA. Although demographic and basic characteristics did not differ between DKA and non-DKA patients, DKA patients needed a significantly higher insulin dosage than non-DKA patients for 2 years after diagnosis. However, control of glycated hemoglobin was not different between the DKA and non-DKA groups during the observation period. In the biochemical analysis, C-peptide, insulin-like growth factor-1, and insulin-like growth factor binding protein 3, high-density lipoprotein cholesterol, free T4, and T3 values were lower, but thyroid-stimulating hormone, initial serum glucose, uric acid, total cholesterol, triglyceride, and low-density lipoprotein cholesterol values were higher in DKA patients than non-DKA patients at the diagnosis of T1DM; however, these differences were temporarily present and disappeared with insulin treatment. Other clinical outcomes, such as height, thyroid function, and urine microalbumin level, did not vary significantly between the DKA and non-DKA groups during 5 years of follow-up. Conclusion DKA at initial presentation reflects the severity of disease progression, and the deleterious effects of DKA seem to impact insulin secretion. Although no difference in long-term prognosis was found, early detection of T1DM should help to reduce DKA-related islet damage and the socioeconomic burden of T1DM.

P-glycoprotein (P-gp) is a transporter that plays an excretory role in epithelial cells. It is encoded by ABCB1, and single nucleotide polymorphisms (SNPs) in this gene can affect systemic drug exposure. Dapagliflozin and sitagliptin, used in type 2 diabetes treatment, are P-gp substrates. Here, we aimed to investigate whether ABCB1 polymorphisms affect dapagliflozin and sitagliptin pharmacokinetics (PK) in healthy Korean subjects.The study population consisted of 100 healthy Korean subjects (94 men and 6 women) who participated in four different clinical trials and received dapagliflozin and sitagliptin doses of 10 and 100 mg, respectively. We determined ABCB1 genotypes for the C3435T, C1236T, and G2677T/A SNPs. The relationship between the genotypes and dapagliflozin PKs was examined.Dapagliflozin and sitagliptin PK parameters were not statistically significantly affected by ABCB1 SNP genotypes. However, homozygous 3435TT subjects showed higher dapagliflozin PK parameters than CT and CC subjects. In subjects with the 3435TT and those with 3435CC and 3435CT genotypes, mean Cmax, AUCinf, and AUC0-1 values of dapagliflozin were 223.06 ng/mL and 194.81 ng /mL (p = 0.2767), 673.58 ng*h/mL and 573.96 ng*h/mL (p = 0.0492), and 128.53 ng*h/mL and 104.61 ng*h/mL (p = 0.2678), respectively.In summary, dapagliflozin and sitagliptin PK parameters were not significantly different between individuals with C1236T and C2677T/A ABCB1 genetic polymorphisms. Dapagliflozin exhibited higher systemic exposure in 3435TT subjects than in CC/CT subjects.

Background and Objectives: Atrial tachycardias (ATs) from noncoronary aortic cusp (NCC) uncovered after radiofrequency ablation for atrial fibrillation (AF) are rarely reported. This study was conducted to investigate the prevalence and clinical characteristics of NCC ATs detected during AF ablation and compare their characteristics with de novo NCC ATs without AF. Methods: Consecutive patients who underwent radiofrequency catheter ablation for AF were reviewed from the multicenter AF ablation registry of 11 tertiary hospitals. The clinical and electrophysiological characteristics of NCC AT newly detected during AF ablation were compared with its comparators (de novo NCC AT ablation cases without AF). Results: Among 10,178 AF cases, including 1,301 redo ablation cases, 8 (0.08%) NCC AT cases were discovered after pulmonary vein isolation (PVI; 0.07% in first ablation and 0.15% in redo ablation cases). All ATs were reproducibly inducible spontaneously or with programmed atrial stimulation without isoproterenol infusion. The P-wave morphological features of tachycardia were variable depending on the case, and most cases exhibited 1:1 atrioventricular conduction. AF recurrence rate after PVI and NCC AT successful ablation was 12.5% (1 of 8). Tachycardia cycle length was shorter than that of 17 de novo ATs from NCC (303 versus 378, p=0.012). No AV block occurred during and after successful AT ablation. Conclusions Uncommon NCC ATs (0.08% in AF ablation cases) uncovered after PVI, showing different characteristics compared to de-novo NCC ATs, should be suspected irrespective of P-wave morphologies when AT shows broad propagation from the anterior interatrial septum.

The phosphorylated 43-kDa transactive response DNA-binding protein (TDP-43) was identified as a major disease protein in sporadic amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration. We present a case with progressive muscle weakness who was diagnosed with sporadic ALS. On postmortem examination, TDP-43 immunoreactive neuronal cytoplasmic inclusions were noted in motor cortex, hippocampus and anterior horns of spinal cord, which was compatible with ALS-TDP, stage 4. This is the first documented autopsy-confirmed ALS case with ALS-TDP pathology in Korea.

Purpose: Antithyroid drugs (ATDs) are primarily used as an initial treatment in pediatric patients with Graves’ disease (GD). We aimed to investigate the long-term outcomes in pediatric GD patients receiving ATDs. Methods: Retrospective data from a single center were collected from April 2003 to July 2020. A total of 98 children and adolescents aged 2–16 years diagnosed with GD and receiving ATDs was enrolled. We investigated the factors correlated with remission by comparing children who achieved remission after 5 years and those with persistent disease. Results: The study included 76 girls (77.6%) and 22 boys (22.4%). During the 5-year follow-up period, 18 children (18.3%) maintained remission, ATDs could not be discontinued in 74 patients (75.5%), and relapse occurred in 6 patients (6.2%). The remission group had significantly lower thyroid-stimulating hormone-binding inhibitory immunoglobulin (TBII) level at diagnosis (P=0.002) and 3 months (P=0.002), 1 year (P=0.002), 2 years (P≤0.001), 3 years (P≤0.001), 4 years (P≤0.001), and 5 years (P≤0.001) after ATD treatment than did the nonremission group. The remission group also had a shorter time for TBII normalization after ATD treatment (P≤0.001). Multiple logistic regression analysis showed that the time to TBII normalization (cutoff time=2.35 years) was related to GD remission (odds ratio, 0.596; 95% confidence interval, 0.374–0.951). Conclusion TBII level and time to TBII normalization after ATD treatment can be used to predict remission in pediatric GD patients.

Background and Objectives: Pacemaker (PM) implantation is a well-accepted treatment option for patients with paroxysmal atrial fibrillation (AF) and related tachycardiabradycardia syndrome (TBS). Data on the long-term clinical outcomes after radiofrequency catheter ablation (RFCA) or PM implantation are sparse. Methods: The medical records of 217 patients with TBS were retrospectively assessed.Outcomes in patients who underwent RFCA (n=108, 49.8%) were compared to those with PM implantation (n=109, 50.2%). The clinical outcomes were sinus rhythm maintenance, conversion to persistent AF, additional procedure or crossover, and the composite of cardiovascular hospitalization and death. Results: During the follow-up period (mean 3.5±2.0 years), the RFCA group, compared to the PM group, showed better sinus rhythm maintenance (adjusted hazard ratio [aHR], 0.27;95% confidence interval [CI], 0.15–0.46; p=0.002) and less progression to persistent AF (aHR, 0.20; 95% CI, 0.06–0.63; p=0.006). Additional procedure or crossover did not differ significantly between the groups (aHR, 2.07; 95% CI, 0.71–6.06; p=0.185 and aHR, 0.69; 95% CI, 10.8–2.67; p=0.590, respectively). Most RFCA patients (92.6%) did not require pacemaker implantation during long term follow-up period (>3.5 years). The composite endpoint of cardiovascular rehospitalization and death was not significantly different between the groups (aHR, 0.92; 95% CI, 0.50–1.66; p=0.769).Background and Objectives: Pacemaker (PM) implantation is a well-accepted treatment option for patients with paroxysmal atrial fibrillation (AF) and related tachycardiabradycardia syndrome (TBS). Data on the long-term clinical outcomes after radiofrequency catheter ablation (RFCA) or PM implantation are sparse. Methods: The medical records of 217 patients with TBS were retrospectively assessed.Outcomes in patients who underwent RFCA (n=108, 49.8%) were compared to those with PM implantation (n=109, 50.2%). The clinical outcomes were sinus rhythm maintenance, conversion to persistent AF, additional procedure or crossover, and the composite of cardiovascular hospitalization and death. Results: During the follow-up period (mean 3.5±2.0 years), the RFCA group, compared to the PM group, showed better sinus rhythm maintenance (adjusted hazard ratio [aHR], 0.27;95% confidence interval [CI], 0.15–0.46; p=0.002) and less progression to persistent AF (aHR, 0.20; 95% CI, 0.06–0.63; p=0.006). Additional procedure or crossover did not differ significantly between the groups (aHR, 2.07; 95% CI, 0.71–6.06; p=0.185 and aHR, 0.69; 95% CI, 10.8–2.67; p=0.590, respectively). Most RFCA patients (92.6%) did not require pacemaker implantation during long term follow-up period (>3.5 years). The composite endpoint of cardiovascular rehospitalization and death was not significantly different between the groups (aHR, 0.92; 95% CI, 0.50–1.66; p=0.769). Conclusions RFCA is an effective alternative to PM implantation in patients with TBS.In these patients, successful RF ablation of AF is related to a higher rate of sinus rhythm maintenance compared to PM implantation, and the composite outcome of cardiovascular rehospitalization and death is similar.

Background: Multiple system atrophy (MSA) is a sporadic neurodegenerative disease characterized by various combinations of parkinsonism, cerebellar ataxia, autonomic dysfunction and pyramidal signs. Two clinical subtypes are recognized: MSA with predominant cerebellar ataxia (MSA-C) and MSA with predominant parkinsonism (MSA-P). The aim of this study was to compare pathological features between MSA-C and MSA-P. Methods: Two autopsy confirmed cases with MSA were included from the Pusan National University Hospital Brain Bank. Case 1 had been clinically diagnosed as MSA-C and case 2 as MSA-P. The severity of neuronal loss and gliosis as well as the glial and neuronal cytoplasmic inclusions were semiquantitatively assessed in both striatonigral and olivopontocerebellar regions. Based on the grading system, pathological phenotypes of MSA were classified as striatonigral degeneration (SND) predominant (SND type), olivopontocerebellar degeneration (OPC) predominant (OPC type), or equivalent SND and OPC pathology (SND=OPC type). Results: Both cases showed widespread and abundant α-synuclein positive glial cytoplasmic inclusions in association with neurodegenerative changes in striatonigral or olivopontocerebellar structures, leading to the primary pathological diagnosis of MSA. Primary age-related tauopathy was incidentally found but Lewy bodies were not in both cases. The pathological phenotypes of MSA were MSA-OPC type in case 1 and MSA-SND=OPC type in case 2. Conclusions Our data suggest that clinical phenotypes of MSA reflect the pathological characteristics.

Background: The incidence of inappropriate shocks remains high at 30% in patients with implantable cardioverter-defibrillators (ICDs). This retrospective study sought to examine the efficacy of strategic programming (ICD programming with a long detection interval and high-rate cutoff) in reducing electrical storm, inappropriate shocks, and unexpected hospital visits in patients with ICDs with/without cardiac resynchronization therapy with defibrillator (CRT-Ds). Methods: This was a single tertiary center retrospective study, evaluating the clinical outcomes, especially regarding inappropriate therapies in patients with ICDs or CRT-Ds. Enrolled patients underwent ICD or CRT-D implantations from January 2008 to May 2016. Clinical information was attained by a thorough chart review. Results: We analyzed 155 defibrillator patients from January 2008 to May 2016 (124 patients had ICDs and 31 had CRT-Ds). Since we adopted this strategic programming as a default programming from 2015 implanted ICDs and CRT-Ds, we divided the patients into two groups: devices implanted before 2015 (group A, n = 94) versus implanted after 2015 (group B, n = 61). During a median of 1289 days of follow-up, electrical storms occurred in three patients (eight events) in group B versus 11 (28 events) in group A (P = 0.18); appropriate therapies were delivered in 27 patients (56 events) in group A versus 7 (15 events) in group B (P = 0.72); inappropriate therapies were delivered in 15 patients (21 events) in group A versus 1 with 1 episode in group B (P = 0.03); and 5 unexpected hospitalizations occurred in four patients in group B versus 36 in 24 patients in group A (P = 0.02). Conclusion The clinical application of strategic programming reduced inappropriate shocks and unexpected hospitalizations in ICD and CRT-D patients.

Background and Objectives: Liver cirrhosis is accompanied by abnormal vascular shunts. The Wnt pathway is essential for endothelial cell survival and proliferation. C-reactive protein (CRP), which is produced by hepatocyte, activates angiogenesis in cardiovascular diseases. Methods: and Results: The expression of CRP in CCl 4 -injured rat livers was detected using qRT-PCR and Western blotting after transplantation of placenta-derived mesenchymal stem cells (PD-MSCs) into rats. To determine whether CRP functions in hepatic regeneration by promoting angiogenesis through the Wnt pathway, we detected VEGF and β-catenin in liver tissues and BrdU and β-catenin in hepatocytes by immunofluorescence. The expression levels of CRP, Wnt pathway-related and angiogenic factors were increased in CCl 4 -injured and PD-MSCs transplanted rat livers. In vitro, the expression levels of Wnt signaling and angiogenic factors were decreased in siRNA-CRP-transfected rat hepatocytes. Conclusions CRP upregulation by PD-MSCs participates in vascular remodeling to promote liver regeneration via the Wnt signaling pathway during hepatic failure.