Jaemin Shim

Jeong JH, et al. J Korean Med Sci. 2027 Jan;42:e9. https://doi.org/10.3346/jkms.2027.42.e9

Kim Y, et al. Korean Circ J. 2027 ;57:e2. https://doi.org/10.4070/kcj.2025.0259

Background/Objectives: Left atrial (LA) low-voltage area quantification is time-consuming and threshold-dependent. We investigated whether mean left atrial bipolar voltage, as a marker of atrial cardiomyopathy, is associated with prior ischemic stroke and compared its performance with low-voltage area percentage (LVA%). Methods: In this single-center retrospective cross-sectional study, 259 consecutive patients with atrial fibrillation (AF) undergoing radiofrequency catheter ablation were enrolled. Mean LA voltage was calculated as the arithmetic mean of all bipolar voltage points acquired during electroanatomic mapping. LVA% was defined as the proportion of LA surface area with voltage < 0.5 mV. Associations with prior ischemic stroke were assessed using Firth’s penalized logistic regression. Results: The median age was 67 years and 31.7% were women. Twenty-nine patients (11.2%) had prior ischemic stroke. Patients with prior stroke had significantly lower mean LA voltage (0.5 [0.4–0.8] vs. 1.0 [0.6–1.3] mV, p < 0.001). After adjustment for CHA₂DS₂-VASc components, mean LA voltage remained independently associated with prior stroke (odds ratio 0.12, 95% confidence interval 0.03–0.38; p < 0.001). Mean LA voltage and LVA% showed comparable discrimination (area under the curve 0.743 vs. 0.717; p = 0.392), but adding mean LA voltage to the LVA%-only model improved model fit (likelihood ratio test p = 0.024). Conclusions: In this cross-sectional cohort, lower mean LA voltage was independently associated with prior ischemic stroke and may better reflect the extent of underlying atrial remodeling than LVA%.

Introduction: Patient characteristics and predictors of early (ERAT) and late (LRAT) recurrence of atrial tachyarrhythmia by atrial fibrillation (AF) type after cryoballoon ablation (CBA) remain poorly defined. Methods: Using the Korean Heart Rhythm Cryoballoon Registry (12 centers, 2018–2022), 2051 patients undergoing CBA for drug‐refractory AF were stratified by AF type. ERAT was defined as atrial tachyarrhythmia within the 3‐month blanking period and LRAT as recurrence beyond 3 months. Independent predictors of ERAT (all patients) and LRAT (patients without ERAT) were identified. Results: ERAT occurred in 631 patients (30.8%; 17.6% in paroxysmal and 40.4% in persistent AF). Among 1420 patients without ERAT, LRAT occurred in 311 (21.9%; 16.7% paroxysmal, 27.2% persistent). In paroxysmal AF, coronary artery disease (HR 1.60; 95% CI, 1.00–2.56; p = 0.048) and LA enlargement (HR 1.07; 95% CI, 1.04–1.10; p < 0.001) predicted ERAT, whereas hypertrophic cardiomyopathy (HR 5.01; 95% CI, 2.20–11.42; p < 0.001) and LA enlargement (HR 1.04; 95% CI, 1.01–1.08; p = 0.019) predicted LRAT. In persistent AF, AF duration (HR 1.04; 95% CI, 1.02–1.06; p < 0.001) and LA enlargement (HR 1.03; 95% CI, 1.02–1.04; p < 0.001) predicted ERAT, and LA enlargement (HR 1.03; 95% CI, 1.01–1.05; p = 0.010) independently predicted LRAT. Conclusion: Predictors of ERAT and LRAT differed between patients with paroxysmal and those with persistent AF. LA enlargement was the most consistently shared predictor across recurrence phenotypes.

Background: Evidence for non-vitamin K antagonist oral anticoagulant (NOAC) monotherapy for older patients with atrial fibrillation (AF) and drug-eluting stents is lacking. Objectives: We aimed to evaluate the safety and efficacy of NOAC monotherapy in older AF patients with drug-eluting stents. Methods: This is a secondary analysis of the ADAPT AF-DES randomised trial comparing NOAC monotherapy with combination therapy with NOAC plus clopidogrel in patients with AF and drug-eluting stents. Patients were stratified by age (≥75 years and <75 years). Apixaban or rivaroxaban was used as the NOAC. The primary endpoint was a net adverse clinical event at 1 year after randomisation, defined as a composite of all-cause death, myocardial infarction, stent thrombosis, stroke, systemic embolism or major or clinically relevant non-major bleeding defined by the International Society on Thrombosis and Haemostasis criteria. Results: Among 960 patients included in the ADAPT AF-DES trial, 376 (39.2%) patients were aged ≥75 years. In patients aged ≥75 years, the incidence of the primary endpoint was lower in the NOAC monotherapy group (9.8% vs. 22.3%; adjusted hazard ratio, 0.37; 95% confidence interval, 0.21–0.66; P < .001) than in the combination therapy group. In contrast, the incidences did not differ between treatment strategies in patients aged <75 years. The interaction between age groups and strategy groups did not reach statistical significance (P for interaction = .095). The reduction in major or clinically relevant non-major bleeding with NOAC monotherapy was consistent across age groups. In contrast, the benefit of NOAC monotherapy in major adverse cardiac and cerebrovascular events was more pronounced in patients aged ≥75 years, with a statistically significant interaction. Conclusions: In this post hoc analysis, NOAC monotherapy was associated with a lower risk of net adverse clinical events, specifically within the older age subgroup. Tailored approach regarding age and individual ischaemic risk may be needed.

Background: Atrioventricular (AV) conduction disturbances in bicuspid aortic valve (BAV) patients are typically attributed to age-related fibrosis or post-surgical trauma. Direct mechanical impingement of the conduction system by accelerated valvular calcification causing reversible, dynamic AV block is rarely reported. Case Summary: A 43-year-old male presented with syncope. Electrocardiograms revealed dynamic high-grade AV block and alternating bundle branch block (ABBB). Echocardiography and computed tomography identified a BAV with a calcified spur extending into the membranous interventricular septum, mechanically compressing the His bundle during the cardiac cycle. Additionally, a hypermobile mass—initially suspected as infective vegetation—was attached to the calcification. To prevent embolic events and address the root cause of the conduction block, surgical tissue-sparing resection was performed. Histopathology confirmed the mass as a reactive thrombus formed on the calcified nodule. Postoperatively, normal sinus rhythm was successfully restored, completely obviating the need for permanent pacemaker implantation. Discussion: This case highlights that dynamic conduction disturbances, such as ABBB, in BAV patients can stem from reversible mechanical compression rather than intrinsic irreversible fibrosis. Furthermore, calcific extensions can create local turbulence and surface irregularities, acting as a nidus for thrombus formation that mimics vegetation. When young BAV patients present with unexplained dynamic AV block, meticulous evaluation for calcific extension is essential. In selected cases, surgical resection targets the underlying pathology, offering a curative alternative to lifelong pacing while simultaneously eliminating embolic risks.

Prognosis and risk markers of sudden cardiac death (SCD) remain incompletely defined in patients with apical hypertrophic cardiomyopathy (HCM). This study evaluated established SCD risk markers and compared long-term implantable cardioverter-defibrillator (ICD) therapy outcomes between apical and non-apical HCM. We analyzed 96 patients with HCM who underwent ICD implantation at 3 tertiary care hospitals in Korea. All SCD risk markers recommended by the 2024 American Heart Association (AHA)/American College of Cardiology (ACC) and 2023 European Society of Cardiology (ESC) guidelines were assessed in apical HCM patients who experienced aborted cardiac arrest (ACA) and/or documented ventricular fibrillation (VF). The long-term outcomes of ICD therapies between apical and non-apical HCM patients were evaluated. Of the 15 patients (15.6%) with apical HCM, 7 (46.7%) experienced ACA and/or documented VF. All 7 patients had at least one SCD risk marker as defined by the 2024 AHA/ACC or 2023 ESC guidelines. The most common markers were late gadolinium enhancement, unexplained syncope, non-sustained ventricular tachycardia, and left atrial enlargement. No significant differences were observed in total (33.3% [5/15] vs. 30.9% [25/81], p=1.00) or appropriate (13.3% [2/15] vs. 19.8% [16/81], p=0.73) ICD therapy events between patients with apical and non-apical HCM over a mean follow-up of 6.03±4.75 years. Patients with apical HCM who received ICDs for secondary prevention exhibited substantial risk markers at the index event and remained at risk for recurrent ventricular arrhythmias. These findings support risk-guided ICD implantation and careful long-term follow-up in patients with high-risk apical HCM.

Background and Aims: Esophageal injury (EI) is a potentially serious complication of catheter ablation (CA) for atrial fibrillation (AF). However, data on its incidence and risk factors, particularly after radiofrequency catheter ablation (RFCA) and cryoballoon ablation (CBA), remain limited. This study aimed to identify predictors of EI in patients undergoing RFCA and CBA. Methods: In this retrospective study, patients with AF who underwent de novo RFCA or CBA between December 2019 and April 2022 were evaluated. All underwent EGD within 2 days post‐ablation. EI severity was graded, and clinical predictors were analyzed using multivariate logistic regression. Results: Among 584 patients (mean age 62.8 ± 11.2 years, 68.6% male), 30 (5.1%) developed EI (RFCA: 5.0%, CBA: 6.3%). Most injuries were mild (Class I), and all resolved with proton pump inhibitor therapy. Compared with those without EI, affected patients had significantly lower body mass index (BMI) (24.5 ± 3.9 vs. 25.9 ± 3.4 kg/m ² , p = 0.030) and reduced ejection fraction (EF) (48.9% ± 8.7% vs. 52.8% ± 6.8%, p = 0.023). Multivariate analysis identified BMI ≤ 24 kg/m ² (odds ratio [OR], 3.67; 95% confidence interval [CI], 1.69–7.96) and EF ≤ 40% (OR, 4.08; 95% CI, 1.54–11.56) as independent risk factors. Conclusions: Esophageal injury after catheter ablation for atrial fibrillation is not rare, but usually mild. Lower BMI and reduced LVEF were independent risk factors, regardless of ablation type. These results support selective endoscopic screening in high‐risk patients to enable early detection and prevent severe complications.

Background: Socioeconomic disparities are associated with sudden cardiac arrest (SCA) in older populations, but evidence in young adults is limited. We investigated the association between income status, geographical region and SCA risk among young adults in South Korea. Methods: Using the Korean National Health Insurance Service database, we identified 6 307 644 adults aged 20–39 years who underwent health screening between 2009 and 2012. Income status was defined by insurance premium quartiles and medical aid status. The primary outcome was incident SCA through December 2020. Multivariable Cox regression models were used to estimate adjusted HRs with 95% CIs. Results: Over a mean follow-up of 9.4 years, 5340 individuals (0.08%) experienced SCA. Crude incidence rates were similar across income quartiles (0.09 per 1000 person-years) but highest among medical aid beneficiaries (0.28 per 1000 person-years; 95% CI 0.21 to 0.39). After multivariable adjustment, higher income was associated with lower SCA risk (adjusted HR for highest vs lowest quartile 0.67; 95% CI 0.61 to 0.73), while medical aid beneficiaries had substantially higher risk (adjusted HR 3.44; 95% CI 2.49 to 4.74). Geographical variation in SCA incidence was modest, and no significant interaction between income status and region was observed. Mediation analysis showed that modifiable risk factors explained only a small proportion of the income–SCA association. Conclusions: Lower income status, particularly receipt of medical aid, was independently associated with higher SCA risk among young adults. Socioeconomic disparities in SCA risk were not fully explained by lifestyle or metabolic factors.

Shim J, et al. Korean J Radiol. 2026 May;27(5):419-427. https://doi.org/10.3348/kjr.2025.1622