Clinical relevance of left atrial structural remodeling and non-pulmonary vein foci in atrial fibrillation.

Background: The mechanistic role of left atrial (LA) structural remodeling as a non-pulmonary vein (PV) trigger in the initiation of atrial fibrillation (AF) remains uncertain. This study is aimed at prospectively evaluating the association between non-PV triggers and LA structural remodeling.

Methods: A total of 517 patients undergoing catheter ablation for AF were included.

Correlation between thromboembolic risk and prevalence of coronary artery disease in patients with atrial fibrillation and impaired renal function.

Background: Atrial fibrillation (AF) and coronary artery disease (CAD) often co-occur. The prevalence of coincident AF and CAD, the characteristics of such patients, and the correlation with thromboembolic risk in association with renal function are unclear.

Methods And Results: We studied 435 consecutive patients who underwent contrast-enhanced computed tomography (CT) before catheter ablation for AF.

Prognostic significance of the Holter-derived T-wave variability in patients with ventricular tachyarrhythmias complicating acute coronary syndrome-TWIST study.

Background: We aimed to investigate the association between ventricular repolarization instability and sustained ventricular tachycardia and ventricular fibrillation (VT/VF) occurring within 48 h (acute-phase VT/VF) after the onset of acute coronary syndrome (ACS) and the prognostic role of repolarization instability and heart rate variability (HRV) after discharge from the hospital.

Methods: We studied 572 ACS patients with a left ventricular ejection fraction >35%. The ventricular repolarization instability was assessed by the beat-to-beat T-wave amplitude variability (TAV) using high-resolution 24-h Holter ECGs recorded at a median of 11 days from the date of admission.

Utility of open-window mapping for catheter ablation of an accessory pathway in patients with Wolff-Parkinson-White syndrome.

Background: Open-window mapping (OWM) is a novel automated mapping method for catheter ablation of an accessory pathway (AP), in which the local signal is annotated with window-of-interest parameters to analyze both atrial and ventricular signals. This study aimed to determine the utility of OWM in visualizing the location and width of APs in patients with Wolff-Parkinson-White syndrome.

Methods: This two-center study enrolled 30 patients (20 males; mean age: 56 years, interquartile range [IQR]: 22-69 years) who underwent high-density OWM with the extended early-meets-late (EEML) algorithm using a 20-electrode, 5-spline catheter (PENTARAY, Biosense Webster).

Utility and limitations of coherent mapping algorithm utilizing vectors and global propagation patterns in atrial tachycardia.

Background: A novel mapping algorithm utilizing vectors and global patterns of propagation (Coherent™, Biosense Webster) has been developed to help identify the mechanism of atrial tachycardia (AT). We aimed to determine the diagnostic accuracy of coherent mapping compared with that of ripple mapping.

Methods And Results: This study included 41 consecutive patients with 84 ATs (47 reentrant and 37 focal ATs).

Interim Report of a Japanese Phase II Trial for Cardiac Stereotactic Body Radiotherapy in Refractory Ventricular Tachycardia - Focus on Target Determination.

Cardiac radiotherapy using stereotactic body radiation therapy (SBRT) has attracted attention as a minimally invasive treatment for refractory ventricular tachycardia. However, a standardized protocol and software program for determining the irradiation target have not been established. Here, we report the first preclinical stereotactic radioregulation antiarrhythmic therapy trial in Japan, focused on the target-setting process.

Heavy Ion Irradiation Reduces Vulnerability to Atrial Tachyarrhythmias - Gap Junction and Sympathetic Neural Remodeling.

Background: Low-invasive stereotactic body radiation therapy is a novel anti-arrhythmic strategy. The mechanisms underlying its effects against ventricular tachycardia/fibrillation (VT/VF) are gradually becoming clear, whereas those underlying atrial tachycardia/fibrillation (AT/AF) remain unknown. This study investigated the effects of carbon ion beam on gap junction expression and sympathetic innervation.

Ablation index-guided cavotricuspid isthmus ablation with contiguous lesions using fluoroscopy integrated 3D mapping in atrial flutter.

Purpose: The feasibility and safety of cavotricuspid isthmus (CTI) ablation with contiguous lesions using ablation index (AI) under the guidance of fluoroscopy integrated 3D mapping (CARTO UNIVU/CU) in typical atrial flutter (AFL) remains uncertain. This study aimed to determine the efficacy of AI-guided CTI ablation with contiguous lesions in patients with AFL.

Methods: In this single-center, prospective, non-randomized, single-arm, observational study, procedural outcomes were determined in 151 patients undergoing AI-guided CTI ablation (AI group) with a target AI value of 450 and an interlesion distance of ≤ 4 mm under CU guidance.

Late-onset atrioventricular block after transcatheter aortic valve replacement.

Background: Conduction disturbances leading to permanent pacemaker implantation (PPI) rarely occur late after transcatheter aortic valve replacement (TAVR). The clinical features of this phenomenon and its association with periprocedural conduction disturbances remain uncertain.

Objectives: We aimed to determine the incidence and characteristics of late-onset atrioventricular block (AVB) after TAVR.

Clinical Significance of the Head-Up Tilt Test in Improving Prognosis in Patients with Possible Neurally Mediated Syncope.

Syncope is commonly encountered in daily clinical practice. Depending on its etiology (benign or life-threatening conditions or environmental triggers), syncope can be neurally mediated (reflex), cardiac, or orthostatic. Furthermore, neurologic disease can cause symptoms that mimic syncope.

Impact of exercise capacity on the long-term incidence of atrial arrhythmias in heart failure.

We sought to demonstrate the impact of improved peak exercise oxygen consumption (V̇O) during maximal exercise testing after cardiac rehabilitation (CR) on the incidence of arrhythmias in patients with heart failure (HF). The present study comprised of 220 patients with HF, and peak V̇O was examined at 2 and 5 months after CR. Of the 220 patients, 110 (50%) had a low peak V̇O of < 14 mL/min/kg at 2 months.

Diagnosis and prevention of the vasodepressor type of neurally mediated syncope in Japanese patients.

We investigated circulatory dynamics in patients with vasodepressor type neurally mediated syncope (VT-NMS) by performing high-resolution Holter electrocardiography and a correlation analysis of changes in adenylate cyclase activity, blood pressure, and pulse during the head-up tilt test. Holter electrocardiography was performed for 30 patients. Adenylate cyclase activity was evaluated in lymphocytes from blood samples taken at rest and during the head-up tilt test.