Feasibility of Atrial Substrate Mapping During Atrial Pacing and Its Impact on the Omnipolar Voltage and the Peak-Frequency of Electrograms.

Introduction: Atrial pacing maps are often used as substitutes for sinus rhythm (SR) maps to expedite mapping procedures. However, the impact of this method on electrophysiological parameters has not been systematically examined. This study aimed to elucidate the advantages and limitations of atrial pacing maps.

Efficacy and Safety of High-Power Short-Duration Ablation for Cavo-Tricuspid Isthmus With a Flexible-Tip Temperature-Controlled Power Regulation Catheter Performed by Electrophysiology Trainees.

Introduction: The suitability of high-power short-duration (HPSD) cavo-tricuspid isthmus ablation (CTI-Abl) for electrophysiology (EP) trainees, as well as the underlying mechanisms of its efficacy, remain unknown. The aim of this study was to clarify the efficacy and safety of HPSD CTI-Abl performed by EP trainees and assess lesion characteristics between HPSD and moderate-power long duration (MPLD) ablations.

Methods: Study 1: CTI-Abl was performed by first- to fourth-year EP trainees in consecutive 113 patients (67 ± 11 years, 27.

Significance of the local largest bipolar voltage for the optimized ablation strategy using very high-power short duration mode.

Purpose: Very high-power short-duration (vHPSD) ablation creates shallower lesions, potentially reducing efficacy. This study aims to identify factors leading to insufficient lesions during pulmonary vein antral isolation (PVAI) with vHPSD-ablation and to develop an optimized PVAI strategy using this technology.

Methods: PVAI was performed on 41 atrial fibrillation patients using vHPSD-ablation (90 W/4 s).

Feasibility and safety assessment of RF double applications in very high power and short duration ablation.

Background: Very high power and short duration (vHPSD) ablation is recently used for pulmonary vein isolation. However, low first-pass isolation rates have been reported, possibly because of shallow lesion formation, necessitating deeper lesions to improve treatment outcomes.

Objective: This study aimed to confirm the safety and efficacy of double radiofrequency applications of vHPSD ablation in an in vivo beating swine heart model.

Quantitative investigation of acute lesions created by ethanol infusion into the vein of Marshall.

Background: Ethanol infusion into the vein of Marshall (EIVOM) has been performed as an adjunctive atrial fibrillation therapy. However, the time course change, quantitative lesion investigation, and effects on epicardial fat pads and fractionated atrial electrograms created by EIVOM have never been investigated.

Objective: This study aimed to perform a quantitative analysis of lesions created by EIVOM.

An optimized approach for increasing lesion size in temperature-controled setting using a catheter with a surface thermocouple and efficient irrigation.

Background: We explore an optimized approach for increasing lesion size using a novel ablation catheter with a surface thermocouple and efficient irrigation in a temperature-control setting.

Methods: We conducted radiofrequency applications at various power levels (35 W, 40 W, and 45 W), contact forces (CFs, 10 g/20 g), and durations (60 s/120 s/180 s) in perpendicular/parallel catheter orientations, with normal saline irrigation (NS-irrigation) and Half NS-irrigation (HNS-irrigation) in an ex-vivo model (Step 1). In addition, we performed applications (35 W/40 W/45 W for 60 s/120 s/180 s in NS-irrigation and 35 W/40 W for 60 s/120 s/180 s in HNS-irrigation) in four swine (Step 2), evaluating lesion characteristics and the occurrence of steam pops.

Insights into stereoselective ring formation in canonical strigolactone: Identification of a dirigent domain-containing enzyme catalyzing orobanchol synthesis.

Strigolactones (SLs) are plant apocarotenoids with diverse roles and structures. Canonical SLs, widespread and characterized by structural variations in their tricyclic lactone (ABC-ring), are classified into two types based on C-ring configurations. The steric C-ring configuration emerges during the BC-ring closure, downstream of the biosynthetic intermediate, carlactonoic acid (CLA).

Distribution of peak frequency and omnipolar voltage in electrograms across the atrial body and thoracic veins in a normal heart.

Background: The innovative peak frequency mapping facilitates the quantification of electrogram sharpness. However, reference values for normal atrial tissue are currently undefined. In this study, we explored the distribution of peak frequency and omnipolar peak-to-peak voltage (V-max) in a normal heart.

Anatomical approach to suppression of para-Hisian ventricular arrhythmias with changes in QRS morphology after ablation at the earliest activation site.

Background: The anatomical approach for the management of para-Hisian ventricular arrhythmias (VAs) with QRS morphological changes after catheter ablation (CA) has not been well investigated.

Objective: We aimed to evaluate the electrocardiographic and electrophysiological findings and ablation outcomes of para-Hisian VAs with QRS morphological changes after CA.

Methods: Of the 30 patients who underwent CA for para-Hisian VAs at 4 institutions, 10 (33%) had QRS morphological changes after ablation.

Impact of contact force on the lesion characteristics of very high-power short-duration ablation using a QDOT-MICRO catheter.

Background: Lesion size is reported to become larger as contact force (CF) increases. However, this has not been systematically evaluated in temperature-guided very high-power short-duration (vHPSD) ablation, which was therefore the purpose of this study.

Methods: Radiofrequency applications (90 W/4 s, temperature-control mode) were performed in excised porcine myocardium with four different CFs of 5, 15, 25, and 35 g using QDOT-MICRO™ catheter.

Effect of Chronic Ethanol Consumption on Exogenous Glucose Metabolism in Rats Using [1-C], [2-C], and [3-C]glucose Breath Tests.

The C3 carbon of glucose molecules becomes the C1 carbon of pyruvate molecules during glycolysis, and the C1 and C2 carbons of glucose molecules are metabolized in the tricarboxylic acid (TCA) cycle. Utilizing this position-dependent metabolism of C atoms in glucose molecules, [1-C], [2-C], and [3-C]glucose breath tests are used to evaluate glucose metabolism. However, the effects of chronic ethanol consumption remain incompletely understood.

Effect of reference electrode on intracardiac electrograms: Close indifferent electrode vs Wilson central terminal.

Background: Unipolar electrograms (uni-EGMs) are an essential part of intracardiac mapping. Although Wilson central terminal (WCT) is conventionally used as a reference for signals, avoidance of contamination by far-field and nonphysiologic signals is challenging.

Objective: The aim of the study was to explore the impact of an intracardiac indifferent reference electrode close to the recording electrodes, in lieu of WCT, on electrograms.

Phrenic nerve injury after atrial fibrillation ablation: different recovery courses among cryoballoon, laser balloon, and radiofrequency ablation.

Background: Phrenic nerve injury (PNI) is one of the common complications in atrial fibrillation (AF) ablation, which often recovers spontaneously. However, the course of its recovery has not been examined fully, especially in regard to the different ablation methods. We sought to compare the recovery course of PNI in cryoballoon, laser balloon, and radiofrequency ablation.

Transcoronary mapping with an over-the-wire multielectrode catheter in scar-related ventricular tachycardia patients.

Aims: The usefulness of coronary venous system mapping has been reported for assessing intramural and epicardial substrates in patients with scar-related ventricular tachycardia (VT). However, there has been little data on mapping from coronary arteries. We investigated the safety and utility of mapping from coronary arteries with a novel over-the-wire multielectrode catheter in scar-related VT patients.

Safety verification of a novel irrigation catheter with flexible tip of laser-cut kerfs and contact force sensor.

Background And Aims: The safety evaluation of TactiFlex, a novel contact-force sensing catheter with a flexible 4-mm tip irrigated through laser-cut kerfs, has been ongoing. This study aimed to verify the safety of this type of catheter.

Methods: Study 1: Radiofrequency (RF) applications at a range of powers (30-50 W), contact forces (10-20 g), and durations (10-60 s) using perpendicular/parallel catheter orientation with half-normal (HNS) or normal saline irrigation were compared between TactiFlex (4-mm tip) and TactiCath (3.

Adjunctive posterior wall isolation for the treatment of persistent and longstanding persistent atrial fibrillation (CORNERSTONE AF) trial: Design and rationale.

Background: A left atrial posterior wall isolation (LAPWI) is one of the atrial fibrillation (AF) ablation strategies.

Hypothesis: We hypothesized that an additional empirical LAPWI would increase the freedom from recurrent atrial arrhythmias as compared to standard AF ablation in persistent AF patients.

Methods: The CORNERSTONE AF study is a prospective, randomized, multicenter study investigating patients with AF persisting for >7 days and <3 years undergoing first-time AF ablation.

How to perform effective cryoballooon ablation of the left atrial roof: Considerations after experiencing more than 1000 cases.

Introduction: Cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to a pulmonary vein isolation has been expected to improve the clinical outcomes post-atrial fibrillation (AF) ablation. We demonstrated the characteristics and efficacy of CBA of the LA roof through our experience with a large volume of procedures.

Methods: Among 1036 AF ablation procedures with CBA of the LA roof, 834 patients who underwent a de novo ablation were analyzed.

Novel method to avoid serious injurious effects on the atrioventricular nodal (AVN) conduction during catheter ablation of the AVN slow pathway utilizing cryofreezing energy.

Background: Slow pathway elimination of the atrioventricular node (AVN) is essential to treat AVN reentrant tachycardia (AVNRT). However, injury to the AVN conduction (IAVN) is one of the serious complications. Cryofreezing energy is expected to reduce the incidence of IAVN.

The association of serum adiponectin level with activities of daily living in hospitalized elderly patients with heart failure.

Background: Several studies have reported a relationship between elevated serum adiponectin levels and poor outcomes in patients with heart failure (HF). However, data on the activities of daily living (ADL) in elderly patients with HF are limited.

Methods: We evaluated 218 hospitalized elderly (≥65 years) patients with HF who underwent a comprehensive cardiac rehabilitation (CR) program during hospitalization.

Detailed analysis of tachycardia cycle length aids diagnosis of the mechanism and location of atrial tachycardias.

Aims: Although the mechanism of an atrial tachycardia (AT) can usually be elucidated using modern high-resolution mapping systems, it would be helpful if the AT mechanism and circuit could be predicted before initiating mapping.

Objective: We examined if the information gathered from the cycle length (CL) of the tachycardia can help predict the AT-mechanism and its localization.

Methods: One hundred and thirty-eight activation maps of ATs including eight focal-ATs, 94 macroreentrant-ATs, and 36 localized-ATs in 95 patients were retrospectively reviewed.

Incidence of antiresorptive agent-related osteonecrosis of the jaw: A multicenter retrospective epidemiological study in Hyogo Prefecture, Japan.

Background/purpose: The incidence of medication-related osteonecrosis of the jaw is increasing worldwide, mostly due to the use of antiresorptive agents (ARAs) such as bisphosphonate (BP) and denosumab (Dmab). However, the proportion of BP-related osteonecrosis of the jaw (BRONJ) and Dmab-related osteonecrosis of the jaw (DRONJ) among all ARA-related osteonecrosis of the jaw (ARONJ) cases is not clear; this hinders appropriate treatment, recurrence-prevention planning, and avoidance of unnecessary Dmab withdrawal. Moreover, the causative drug administered at each disease stage remains unknown.

Impact of baseline pool impedance on lesion metrics and steam pops in catheter ablation.

Introduction: Little is known about the impact of blood-pool local impedance (LI) on lesion characteristics and the incidence of steam pops.

Methods: Radiofrequency applications at a range of powers (30, 40, and 50 W), contact forces (CF) (5, 15, and 25 g), and durations (15, 30, 45, and 120 s) using perpendicular/parallel catheter orientation were performed in 40 excised porcine preparations, using a catheter capable of monitoring LI (StablePoint©, Boston Scientific). To simulate the variability in blood-pool impedance, the saline-pool LI was modulated by calibrating saline concentrations.