Intervention to the modifiable risk factors is important in the comprehensive management of atrial fibrillation（AF）. Although periodontitis is highly prevalent and can be modified by dental intervention, it has not been recognized as a risk factor for AF. This study aimed to investigate the relationship between periodontitis and atrial fibrosis which is known as an AF substrate. Seventy-six patients with AF who underwent left atrial appendage（LAA）resection during surgery were included. LAA patients received a periodontal examination before the surgery in which periodontal inflamed surface area（PISA）was measured as a quantitative index of periodontitis. The degree of atrial fibrosis was histologically quantified using the LAA. We found that PISA was positively correlated with the degree of atrial fibrosis（R＝0.46 ; P＜0.0001）. After adjusting for age, body mass index, AF duration, mitral valve regurgitation, and CHADS₂（congestive heart failure, hypertension, age, diabetes, previous stroke/transient ischemic attack）score, PISA was independently associated with the degree of atrial fibrosis（β＝0.016 ; P＝0.0002）. This study histologically revealed the association of periodontitis with atrial fibrosis in patients with AF. Periodontitis may worsen atrial fibrosis by eliciting systemic inflammation, which may be causative for AF occurrence and perpetuation. Further clinical and basic evidence will be required to confirm that periodontitis is a modifiable risk factor for AF, and the medical-dental cooperation in the comprehensive management of AF may be essential.

An aberrant increase in diastolic calcium（Ca2+）level is a hallmark of heart failure（HF）and the cause of delayed afterdepolarization and ventricular arrhythmia（VA）. Although mitochondria play a crucial role in Ca2+ regulation, their ability to counteract or compensate for aberrant increases in cytosolic Ca2+ levels, which frequently occur in HF, remains unclear. Therefore, we investigated whether enhanced Ca2+ uptake of mitochondria may compensate for abnormal increases in the Ca2+ of ventricular myocytes in HF to effectively mitigate VA. We used a HF mouse model in which myocardial infarction was induced by permanent left anterior descending coronary artery ligation. The mitochondrial Ca2+ uniporter（MCU）was stimulated by kaempferol. Ca2+ dynamics and membrane potential were measured using an epifluorescence microscope, a confocal microscope, and the perforated patch-clamp technique. We analyzed the inducibility of VA in Langendorff-perfused hearts and in mice administered kaempferol using an implantable osmotic minipump. Hemodynamic parameters were measured using a microtip transducer catheter. Protein expression of MCU did not change between HF and sham mice. Treatment of cardiomyocytes with kaempferol, isolated from HF mice at 28 days after coronary ligation, reduced the appearance of aberrant diastolic Ca2+ waves and sparks and spontaneous action potentials. Kaempferol effectively reduced the inducibility of VA. Intravenous administration of kaempferol did not markedly affect left ventricular hemodynamic parameters. The effects of kaempferol in HF of mice implied that mitochondria may have the potential to compensate for abnormal Ca2+. Mechanisms involved in mitochondrial Ca2+ uptake may provide novel targets to treat HF-associated VA.

【Purpose】This study aimed to investigate the threshold for discriminating between aortic and pulmonary valve positions in the Voltage Map of the CARTO^® System using the high-value potential waves of Outflow Tract Ventricular Premature Contractions（OTVPC）. 【Method】In cases where coronary or pulmonary artery angiography was conducted, the study utilized the peak values［mV］of OTVPC obtained through conventional catheters in the left ventricular outflow tract（LVOT）and right ventricular outflow tract（RVOT）. Discrimination thresholds were calculated using Receiver Operating Characteristic（ROC）analysis and Diagnostic Performance Plot（DP）. 【Results】For LVOT bipolar potentials（Bi）, the Best cut-off value（BC）was 0.76［mV］, the Area Under the ROC-Curve（AUC）was 0.92. For RVOT Bi, BC was 0.59［mV］, and AUC was 0.95. Based on DP, the discrimination thresholds for LVOT Bi, ensuring 95％ accuracy, were ≤0.48 for the valve-up position and ≥2.56 for the valve-down position. For RVOT Bi, the thresholds were ≤0.4 for valve-up and ≥0.34 for valve-down. 【Conclusion】The discriminative capability between the aortic and pulmonary valve positions using the peak potential values of Outflow Tract Ventricular Premature Contractions（OTVPC）was excellent with bipolar potentials（Bi）. Specific threshold values for each position were identified.

We have started using the Atrial Fibrillation Early Detection Support Service（AF Detector）, which incorporates a patch-type, 7-day, single-lead electrocardiogram（ECG recorder Heartnote^TM, JSR Corporation）and AI-enabled ECG analysis software（SmartRobin）after 2023. This study assesses SmartRobin’s performance and utility in detecting atrial fibrillation（AF）within real-world clinical settings. This retrospective study evaluated 100 consecutive patients who underwent AF detection using the AF Detector at our hospital from January to August 2023. To assess SmartRobin’s accuracy, an independent arrhythmia specialist confirmed AF diagnoses. The specialist analysis revealed that SmartRobin’s AF detection achieved the sensitivity of 100％ and the specificity of 69％ at the patient level. The critical need to ensure AF detection underlines SmartRobin’s significant utility as a diagnostic support system. Its integration with patch ECGs, noted for high patient adherence, brings its broader adoption. Improving specificity in SmartRobin’s decision is a challenge for future development.

A 59-year-old man underwent a reparative operation for tetralogy of Fallot and received an implanted epicardial pacemaker lead system in childhood. He was diagnosed with pacemaker infection in the left thoracic area. His generator was removed with partial resection of the epicardial leads, and a new device was implanted in his right prepectoral area. Debridement was performed several times. The wound did not heal, and residural epicardial pacemaker lead infection continued for 32 years. He came to our hospital and underwent complete removal of infected epicardial pacemaker lead through the 6th intercostal space. Postoperative course was uneventful. There was no sign of re-infection during a 6-month follow-up.

An implantable cardioverter-defibrillator （ICD） is recommended for catecholaminergic Polymorphic Ventricular Tachycardia （CPVT） when syncope or cardiac arrest occurs despite medication and exercise restriction, but there is no rule for when cardiac arrest occurs in previously undiagnosed patients. We experienced a case of CPVT with VF in which a wearable cardioverter defibrillator （WCD） was used to determine the indication for an ICD. A 9-year-old girl had VF while running and recovered after two defibrillation cycles. Bidirectional Ventricular Tachycardia （VT） and Ventricular Fibrillation （VF） occurred on stimulation of endotracheal intubation in our hospital. CPVT was diagnosed and she was discharged without arrhythmia on antiarrhythmic drugs. The WCD was introduced as a bridge until the decision was made to implant an ICD because of concerns about the effects of changes in environment and level of activity after discharge. There was no shock during the wearing period with only oral medication and exercise restriction and the ICD was not implanted. ICDs are recommended for secondary prevention of VF, but indications are limited in CPVT due to the potential for inappropriate shock to induce arrhythmias. A WCD was safety in determining ICD indications in CPVT with VF onset.