Purpose: We used arterial spin labeling (ASL) perfusion magnetic resonance (MR) imaging to evaluate cerebral perfusion abnormalities in patients with seizures within 24 hours of symptom onset. Materials and Methods: A retrospective search of our institutional database identified 27 patients who had undergone ASL perfusion studies for seizures or seizure-like symptoms.The inclusion criteria were as follows: 1) history of seizure, 2) MR examination performed within 24 hour of seizure onset, and 3) localized perfusion abnormality on ASL. We evaluated the presence, location, and extent of perfusion abnormalities on ASL and signal abnormalities on fluid-attenuated inversion recovery (FLAIR), diffusion-weighted image (DWI), and susceptibility-weighted image (SWI), respectively. All pathological MR findings, accompanying focal neurological symptoms, and electroencephalogram (EEG) findings were compared. Results: The mean time from symptom onset to MR examination was 5 h 54 min. All patients (n = 27) showed localized increased perfusion on ASL perfusion imaging. On FLAIR imaging, 20 patients (74.1%) showed hyperintensity in the area of perfusion abnormality.In 19 patients (70.4%), DWI showed hyperintensity of the lesion with decreased apparent diffusion coefficient value (ADC). Seven patients (25.9%) showed a focal parenchymal area of pseudo-narrowed cortical veins on SWI, associated with focal hyperperfusion. In 20 patients (74.1%), the extent of perfusion abnormalities on ASL was greater than that of signal abnormalities on FLAIR or DWI. In 14/16 patients (87.5%) with abnormal EEG findings, the area with EEG findings and the location of the hyperperfusion abnormality on ASL corresponded. Conclusion In patients with seizures within 24 hours of symptom onset, ASL perfusion imaging revealed localized hyperperfusion, which was more frequent than signal intensity abnormalities on FLAIR or DWI. The locations of hyperperfusion areas correlated with EEG abnormalities. Thus, the ASL sequence may be a useful clinical assessment protocol for evaluating patients with seizures.

Background: This study aimed to generate a Z score calculation model for coronary artery diameter of normal children and adolescents to be adopted as the standard calculation method with consensus in clinical practice. Methods: This study was a retrospective, multicenter study that collected data from multiple institutions across South Korea. Data were analyzed to determine the model that best fit the relationship between the diameter of coronary arteries and independent demographic parameters. Linear, power, logarithmic, exponential, and square root polynomial models were tested for best fit. Results: Data of 2,030 subjects were collected from 16 institutions. Separate calculation models for each sex were developed because the impact of demographic variables on the diameter of coronary arteries differs according to sex. The final model was the polynomial formula with an exponential relationship between the diameter of coronary arteries and body surface area using the DuBois formula. Conclusion A new coronary artery diameter Z score model was developed and is anticipated to be applicable in clinical practice. The new model will help establish a consensus-based Z score model.

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 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.

Kawasaki disease (KD) is an acute pediatric vasculitis that affects genetically susceptible infants and children. To identify coding variants that influence susceptibility to KD, we conducted whole exome sequencing of 159 patients with KD and 902 controls, and performed a replication study in an independent 586 cases and 732 controls. We identified five rare coding variants in five genes (FCRLA, PTGER4, IL17F, CARD11, and SIGLEC10) associated with KD (odds ratio [OR], 1.18–4.41; p = 0.0027–0.031). We also performed association analysis in 26 KD patients with coronary artery aneurysms (CAAs; diameter > 5 mm) and 124 patients without CAAs (diameter < 3 mm), and identified another five rare coding variants in five genes (FGFR4, IL31RA, FNDC1, MMP8, and FOXN1), which may be associated with CAA (OR, 3.89–37.3; p = 0.0058–0.0261). These results provide insights into new candidate genes and genetic variants potentially involved in the development of KD and CAA.

Background: This study aims to investigate the current status of AF (atrial fibrillation) catheter ablation in Korea. Methods: The patients who underwent AF catheter ablation from September 2017 to December 2019 were pro‑ spectively enrolled from 37 arrhythmia centers. Demographic data, procedural characteristics, the extent of catheter ablation, acute success of the ablation lesion set, rate and independent risk factor for recurrence of AF were analyzed. Results: A total of 2402 AF patients [paroxysmal AF (PAF) 45.7%, persistent AF (PeAF) 43.1% and redo AF 11.2%] were included. Pulmonary vein isolation (PVI) was performed in 2378 patients (99%) and acute success rate was 97.9%.Additional non-PV ablation (NPVA) were performed in 1648 patients (68.6%). Post-procedural complication rate was 2.2%. One-year AF-free survival rate was 78.6% and the PeAF patients showed poorer survival rate than the ones with other types (PeAF 72.4%, PAF 84.2%, redo AF 80.0%). Additional NPVA did not influence the recurrence of AF in the PAF patients (PVI 17.0% vs. NPVA 14.6%, P value 0.302). However, it showed lower AF recurrence rate in the PeAF patients (PVI 34.9% vs. NPVA 24.4%, P value 0.001). Valvular heart disease, left atrial diameter, PeAF, PVI alone, need of NPVA for terminating AF, and failed ablation were independent predictors of AF recurrence. Conclusions Additional NPVA was associated better rhythm outcome in the patients with PeAF, not in the ones with PAF. The independent risk factors for AF recurrence in Korean population were similar to previous studies. Further research is needed to discover optimal AF ablation strategy.

Treatment of ventricular arrhythmias (VA) usually involves managing the underlying cardiac conditions that cause the arrhythmia. However, managing the underlying disease is often challenging, and catheter ablation, or treatment targeting the VA itself might be required in a few patients. In this article, we explored evidence and recommendations regarding the treatment of VA in patients with structural heart disease focusing on the utilization of catheter ablation in these patients. The administration of optimal medical therapy, insertion of an implantable cardioverter-defibrillator, or resynchronization therapy improves survival in patients with left ventricular dysfunction. The role of catheter ablation in preventing sudden cardiac death remains uncertain in this population. In patients with coronary artery disease, reversing myocardial ischemia via revascularization is important in managing VA. Catheter ablation is recommended in patients with recurrent ventricular tachycardia in a setting of ischemic heart disease. In patients with non-ischemic cardiomyopathies such as dilated cardiomyopathy or hypertrophic cardiomyopathy, catheter ablation may be considered for those presenting with drug-refractory ventricular tachycardia.
Arrhythmias, Cardiac ; Cardiomyopathies ; Cardiomyopathy, Dilated ; Cardiomyopathy, Hypertrophic ; Catheter Ablation ; Catheters ; Coronary Artery Disease ; Death, Sudden, Cardiac ; Defibrillators, Implantable ; Heart Diseases ; Humans ; Myocardial Ischemia ; Tachycardia, Ventricular ; Ventricular Dysfunction, Left

The recommendations outlined constitute the first clinical practice guidelines of the Korean Heart Rhythm Society regarding catheter ablation of ventricular arrhythmias (VA). This is a guideline PART 2, which includes VA in the structurally normal heart, inherited primary arrhythmia syndromes, VA related to congenital heart disease, as well as VA and sudden cardiac death observed in specific populations. In the structurally normal heart, treatment is guided by the occurrence of symptoms or the frequency of arrhythmias that cause ventricular dysfunction over time. Catheter ablation can be recommended in patients in whom anti-arrhythmic medications are ineffective. The sites of origin of arrhythmic activity are known to be the outflow tract, fascicles, papillary muscle, or the annulus. Specific cardiac channelopathies include congenital long QT and Brugada syndrome. This guideline discusses the diagnostic criteria, risk stratification, and treatment of these syndromes. We have included recommendations for adult congenital heart disease. Moreover, we have discussed the management of VA occurring in specific populations such as in patients with psychiatric and neurological disorders, pregnant patients, those with obstructive sleep apnea or drug-related pro-arrhythmias, athletes, and elderly patients.
Adult ; Aged ; Arrhythmias, Cardiac ; Athletes ; Brugada Syndrome ; Catheter Ablation ; Catheters ; Channelopathies ; Death, Sudden, Cardiac ; Heart ; Heart Defects, Congenital ; Humans ; Nervous System Diseases ; Papillary Muscles ; Sleep Apnea, Obstructive ; Ventricular Dysfunction

Ventricular arrhythmias (VA) are a major cause of sudden cardiac death (SCD) in patients with known heart disease. Risk assessment and effective prevention of SCD are key issues in these patients. Implantable cardioverter defibrillator (ICD) insertion effectively treats sustained VA and reduces mortality in patients at high risk of SCD. Appropriate anti-arrhythmic drugs and catheter ablation reduce the VA burden and the occurrence of ICD shocks. In this guideline, authors have described the general examination and medical treatment of patients with VA. Medications and catheter ablation are also used as acute phase therapy for sustained VA.
Arrhythmias, Cardiac ; Catheter Ablation ; Catheters ; Death, Sudden, Cardiac ; Defibrillators ; Heart Diseases ; Humans ; Mortality ; Risk Assessment ; Shock

BACKGROUND AND OBJECTIVES: Despite significant advances in the treatment of acute myocardial infarction (MI), the prevention of sudden cardiac death (SCD), the most common mode of death in patients with MI, remains challenging. Furthermore, previous Korean MI registries did not address the issue of post-MI SCD. Additional risk stratifiers of post-MI SCD are still required to compensate for the limitation of using left ventricular ejection fraction to predict lethal arrhythmic events. SUBJECTS AND METHODS: We designed the first Korean prospective nationwide multicenter registry primarily focused on SCD; the Korean noninvasive Risk Evaluation study for sudden cardiac DEath From INfarction or heart failurE (K-REDEFINE). The registry consists of 2 groups of patients presenting with (1) acute MI or (2) acute heart failure (HF) at 25 tertiary referral cardiovascular centers. The primary endpoint of the MI group study of K-REDEFINE registry is the incidence and risk factors of post-MI SCD. In particular, the association between the risk of SCD and non-invasive Holter-based electrocardiogram (ECG) variables will be evaluated, such as T-wave alternans (marker of repolarization heterogeneity) and heart rate turbulence/variability (a marker of autonomic function). Other secondary study outcomes include atrioventricular arrhythmias, HF-related admission, repeated myocardial ischemic events, stroke, and overall deaths. CONCLUSION AND PERSPECTIVE: The K-REDEFINE registry will provide new prospects for the better management of MI patients with high risk of SCD by clarifying the burden and predictors of SCD and the clinical utility of various non-invasive ambulatory ECG-based variables in risk stratification for SCD in this patient population.
Arrhythmias, Cardiac ; Death, Sudden, Cardiac* ; Electrocardiography ; Heart Failure* ; Heart Rate ; Heart* ; Humans ; Incidence ; Infarction* ; Myocardial Infarction* ; Prospective Studies ; Referral and Consultation ; Registries ; Risk Factors ; Stroke ; Stroke Volume