Kichang Lee

Background: Lone atrial fibrillation (AF) is characterized by the absence of discernible risk factors, yet its long-term prognostic implications remain unclear. We evaluated genetic predisposition to lone AF and conducted a Mendelian randomization (MR) study to assess its causal effect on cardiovascular outcomes. Methods: A genome-wide association study (GWAS) for lone AF, along with common AF was conducted using UK Biobank data. Lone AF was defined as AF occurring without clinical risk factors. Summary-level data for cardiovascular phenotypes were obtained from publicly available GWAS datasets and the causal effects were estimated using MR. Results: We identified 36 single-nucleotide polymorphisms associated with lone AF, including two novel loci. In MR analyses, lone AF was significantly associated with an increased risk of stroke (odds ratio [OR] 2.62, 95% confidence interval [CI] 2.14–3.22) and heart failure (HF) (OR 2.55, 95% CI 2.14–3.04). The associations with coronary artery disease (CAD) (OR 0.90, 95% CI 0.73–1.10) and cardiac death (OR 1.32, 95% CI 0.99–1.77) were not significant. MR analyses of common AF also demonstrated significant associations with stroke (OR 1.86, 95% CI 1.69–2.04) and HF (OR 1.71, 95% CI 1.59–1.84), though the effect sizes were smaller compared to those of lone AF. Conclusions: Genetic predisposition to lone AF is associated with more than a twofold increase in the risk of stroke and HF. However, no clear association was observed between lone AF and CAD or cardiac death.

Introduction: Fluoroless mapping and ablation using a Pentaspline pulsed field ablation catheter has many advantages. This can be achieved using a “tripolar configuration,” which enables high‐quality electroanatomical maps, improves the ability to localize electrograms (EGMs), and minimizes the use of additional mapping catheters compared to the standard bipolar configuration. We aimed to evaluate the benefits of using a tripolar configuration in fluoroless atrial fibrillation ablation compared to the standard bipolar configuration. Methods: In the tripolar pinning configuration, visualization includes not only the 3rd electrode but also the interpolation of electrodes 1, 2, & 4 on each spline. Procedures were performed under general anesthesia, and the EnsiteX system (Abbott, Abbott Park, IL) was used for mapping. Intracardiac echocardiography and electro‐anatomical mapping were used to identify catheter location and record local EGMs. Tripolar and standard bipolar signals were displayed on the same page to evaluate the signals before and after each PFA application. We compared the peak‐to‐peak signal voltage between the tripolar and standard configurations. Results: Ablation was performed in 59 cases (42 males, average age 65 (30–85); 17 females, average age 74 (59–83)) in which we configured the catheter in a tripolar setup for comparison with the standard bipolar setup. Geometry and post‐voltage maps were created using the tripolar signals in 40 of the 59 patients. The average case duration was 85 min (53–198); for pulmonary vein isolation (PVI) alone, the average was 70 min (53–97). The average number of PFA applications was 48 (31–72). Standard bipolar EGMs demonstrated a large far‐field component, as evidenced by significantly higher mean (84%) and root mean square (RMS, 51%) values compared to the tripolar configuration ( p < 0.001). Ectopic atrial foci and atrial flutters were successfully mapped and ablated in four and five patients, respectively. We were able to demonstrate lines of block across the mitral isthmus and the cavotricuspid isthmus ablation. In cases where mapping was performed, geometry creation with the tripoles allowed for field scaling on Ensite X. Conclusion: Integration of the Pentaspline pulsed field ablation catheter with the tripolar configuration is feasible and facilitates fluoroless PVI.

Background: The incidence of epistaxis during nasotracheal intubation via the left nostril is more frequent than that during intubation via the right nostril. This study evaluated the effect of the reverse bevel and tip direction of the nasotracheal tube on the incidence of epistaxis during nasotracheal intubation via the left nostril.Methods: Patients undergoing right-sided maxillofacial surgery requiring left nasotracheal intubation were randomly allocated to the control (tracheal tube in the conventional direction) or reverse (a 180˚ reverse direction, with the tube bevel facing the nasal septum and the leading edge (i.e., the tip) of the bevel pointing away from the nasal septum) groups (n = 37 for both). The primary outcome was the incidence of epistaxis evaluated using videolaryngoscopy. Results: The incidence of epistaxis in the reverse group was significantly lower than that in the control group (9 [24.3%] vs. 20 [54.1%], P = 0.009; relative risk: 0.45, 95% CI [0.24, 0.85], absolute risk reduction: 29.8%, number needed to treat: 3). The severity of epistaxis was significantly lower in the reverse group (P = 0.002). The first attempt nasal passage (P = 0.027) was significantly higher in the reverse group. Postoperative nasal pain was lower (P < 0.001), and patient satisfaction was higher (P < 0.001) in the reverse group. Nasotracheal tube-related complications did not occur in either group.Conclusions: The reverse bevel and tip direction of the nasotracheal tube reduced the incidence and severity of epistaxis and increased patient satisfaction among patients undergoing left nasotracheal intubation.

Intermittent hypoxia (IH) has been extensively studied in recent years, demonstrating adverse and beneficial effects on several physiological systems. However, the precise mechanism underlying its cardiac effects on the heart remains unclear. This study aims to explore the effect of treatment on atrial fibrillation under IH conditions, providing data that can potentially be used in the treatment of heart disease. An atrial fibrillation (AF) model was induced by injecting monocrotaline (MCT, 60 mg/kg) into rats. The study included 32 rats divided into four groups: Control, Control + IH, AF, and AF + IH. We evaluated molecular changes associated with AF using ELISA and Western blot and performed electrophysiological experiments to evaluate AF. Arrhythmia-related calcium and fibrosis markers were investigated. Phosphorylation levels of CaMKII, Phospholamban, and RyR2 all increased in the AF group but decreased in the IH-exposed group. Additionally, fibrosis marker expressions such as SMA, MMP2, MMP9, and TGF-β increased in the AF group but were significantly downregulated with IH treatment. Connexin 43 and AQP4 expression were restored in the IH-treated group. These findings suggest that IH may prevent AF by downregulating the expression of calcium-handling proteins and fibrosis-associated proteins in an AF-induced rat model.

Accurate assessment of the response to the antiarrhythmic drug (AAD) in atrial fibrillation (AF) is crucial to achieve adequate rhythm control. We evaluated the effectiveness of extended cardiac monitoring using an adhesive ECG patch in the detection of drug-refractory paroxysmal AF. Patients diagnosed with paroxysmal AF and receiving AAD therapy were enrolled. The subjects simultaneously underwent 11-day adhesive ECG patch monitoring and a 24-h Holter test. The primary study outcome was a detection rate of drug-refractory AF or atrial tachycardia (AT) lasting ≥30 s. A total of 59 patients were enrolled and completed the study examinations. AF or AT was detected in 28 (47.5%) patients by an 11-day ECG patch monitor and in 8 (13.6%) patients by a 24-h Holter test (p < 0.001). The 11-day ECG patch monitor identified an additional 20 patients (33.8%) with drug-refractory AF not detected by the 24-h Holter, and as a result, the treatment plan was changed in 11 patients (10 catheter ablations, one medication change). In conclusion, extended cardiac rhythm monitoring using an adhesive ECG patch in patients with paroxysmal AF under AAD therapy led to over a threefold higher detection of drug-refractory AF episodes, compared to the 24-h Holter test.

Nephrolithiasis is one of the most common urinary disorders in dogs. Although a majority of kidney calculi are non-obstructive and are likely to be asymptomatic, they can lead to parenchymal loss and obstruction as they progress. Thus, early diagnosis of kidney calculi is important for patient monitoring and better prognosis. However, detecting kidney calculi and monitoring changes in the sizes of the calculi from computed tomography (CT) images is time-consuming for clinicians. This study, in a first of its kind, aims to develop a deep learning model for automatic kidney calculi detection using pre-contrast CT images of dogs. A total of 34,655 transverseimage slices obtained from 76 dogs with kidney calculi were used to develop the deep learning model. Because of the differences in kidney location and calculi sizes in dogs compared to humans, several processing methods were used. The first stage of the models, based on the Attention U-Net (AttUNet), was designed to detect the kidney for the coarse feature map. Five different models–AttUNet, UTNet, TransUNet, SwinUNet, and RBCANet–were used in the second stage to detect the calculi in the kidneys, and the performance of the models was evaluated. Compared with a previously developed model, all the models developed in this study yielded better dice similarity coefficients (DSCs) for the automatic segmentation of the kidney. To detect kidney calculi, RBCANet and SwinUNet yielded the best DSC, which was 0.74. In conclusion, the deep learning model developed in this study can be useful for the automated detection of kidney calculi.

Background: Accurate tip positioning of a peripherally inserted central catheter (PICC) is crucial for optimal drug delivery and avoiding complications. The objective of this study was to evaluate the amplitude ratios of intravascular electrocardiography (ivECG) and external electrocardiography (exECG) according to the tip location.Methods: This retrospective study analyzed ivECG, exECG, and chest X-ray (CXR) of 278 patients who underwent a PICC procedure. The tip-to-carina distance (TCD) was measured using vertebral body units (VBU) on CXR. Tip locations were categorized as follows: Zone 1, malposition (TCD < 0.8 VBU); Zone 2, suboptimal (0.8 VBU ≤ TCD < 1.5 VBU); Zone 3, optimal (1.5 VBU ≤ TCD ≤ 2.4 VBU); Zone 4, deep (TCD > 2.4 VBU). The amplitude ratios between ivECG and exECG and within ivECG were compared in each zone.Results: The ivECG/exECG amplitude ratios of P-wave (Piv/Pex) and QRS-complex (QRiv/QRex and RSiv/RSex) in Zone 3 were significantly higher than in Zones 1 and 2 (adjusted P < 0.05). The ivECG amplitude ratios of the P-wave and QRS-complex (Piv/QRiv and Piv/RSiv) were significantly lower in Zone 3 than in Zones 1 and 2 (adjusted P < 0.001). The calculated TCD using stepwise multiple regression analysis was estimated to be 1.121 + 0.078 × Piv/Pex – 0.172 × Piv/QRiv.Conclusions: Though caution is required, amplitude ratios such as Piv/Pex and Piv/QRiv can help determine tip location during the PICC catheterization procedure.