Maintenance mechanism of paroxysmal atrial fibrillation from the activation occurring within the pulmonary vein: analysis using non-contact mapping.

It is unclear how pulmonary veins (PVs) maintain paroxysmal atrial fibrillation (AF). To clarify the PV's arrhythmogenic role, we examined PV activation sequences during paroxysmal AF. Left superior PV (LSPV) endocardial non-contact mapping was performed after a right PV isolation in 13 paroxysmal AF patients.

Impact of Intensive Low-Density Lipoprotein Cholesterol-Lowering Therapy on Coronary Artery Plaques in Acute Coronary Syndrome.

Acute coronary syndrome (ACS) is associated with a high incidence of unstable plaques beyond the culprit lesion, leading to early recurrence of cardiovascular events. Coronary computed tomography angiography (CCTA) can be used to noninvasively observe plaques throughout the coronary arteries. To evaluate the impact of intensive low-density lipoprotein cholesterol (LDL-C)-lowering therapy on quantitative changes in coronary plaque, assessed using CCTA in a study population with ACS.

Last Entrainment Sequence: A Novel Diagnostic Technique for Atrial Tachycardia Mimicking Other Supraventricular Tachycardias.

Background: Adenosine-sensitive re-entrant atrial tachycardia (AT) originating from near the atrioventricular (AV) node or AV annulus resembles other supraventricular tachycardias (SVTs), and the differential diagnosis is sometimes challenging.

Objectives: This study sought to develop a novel technique to distinguish adenosine-sensitive re-entrant AT from AV nodal re-entrant tachycardia (AVNRT) and orthodromic reciprocating tachycardia (ORT).

Methods: The study retrospectively studied 117 re-entrant SVTs that were successfully entrained by atrial overdrive pacing (AOP) (27 adenosine-sensitive re-entrant ATs, 63 AVNRTs, 27 ORTs).

Efficacy of catheter ablation from the noncoronary aortic cusp of verapamil-sensitive atrial tachycardia arising near the atrioventricular node.

Background: The efficacy of catheter ablation from the noncoronary aortic cusp (NCC) of verapamil-sensitive atrial tachycardia arising near the atrioventricular node (AVN-AT) has yet to be fully clarified.

Objective: We elucidated the determinant of an effective AVN-AT ablation from the NCC.

Methods: After identifying the earliest atrial activation site (EAAS) during tachycardia, the direction of the slow conduction zone (SCZ) of the reentry circuit was identified by demonstrating manifest entrainment in 26 patients with AVN-AT.

Verification of Coronary Computed Tomography-Derived Fractional Flow Reserve Measurement Site for Detection of Significant Coronary Artery Disease.

The optimal site for measuring computed tomography (CT)-derived fractional flow reserve (FFR) to detect significant coronary artery disease (CAD) remains unknown. We investigated how diagnostic performance changes with FFR measurement site. The diagnostic performance of FFR, measured 1-2 cm distal to the stenosis vs.

Comparison of Diagnostic Performance of Fractional Flow Reserve Derived from Coronary Computed Tomographic Angiography Versus Single-Photon Emission Computed Tomographic Myocardial Perfusion Imaging.

Fraction flow reserve (FFR) derived from computed tomography (FFR) has been proposed to be an effective gatekeeper for invasive angiographic referral. The purpose of the present study is to examine the real-world diagnostic performance of FFR and myocardial perfusion imaging as well as to assess the utility of FFR as a gatekeeper for invasive coronary angiography in patients suspected of having obstructive coronary artery disease. Total of 146 consecutive patients underwent both single-photon emission computed tomography (SPECT) and invasive FFR were evaluated.

Comparison of the catheter ablation outcome in patients between targeting the entrance and exit of the reentry circuit in verapamil-sensitive atrial tachycardia originating from the atrioventricular-node vicinity.

Verapamil-sensitive atrial tachycardia originating from the atrioventricular node vicinity (AVN-AT) can be eliminated with radiofrequency energy (RF) deliveries targeting either the entrance or exit of its reentry circuit. However, the outcome of these different approaches has not been clarified well. Thus, we compared the catheter ablation outcome targeting the entrance of reentry circuit, identified by the entrainment method (Ent-Group; 21 patients) with that targeting the earliest atrial activation site (EAAS) during AT (Exit-Group; 16 patients).

Determinants of insufficient improvement in fractional flow reserve following percutaneous coronary intervention.

Fractional flow reserve (FFR) has become an increasingly important index for decision making concerning coronary revascularization. It is commonly accepted that significant improvement in FFR following percutaneous coronary intervention (PCI) is associated with better symptomatic relief and a lower event rate. However, in lesions with insufficient FFR improvement, PCI may not improve prognosis.

Evaluation of an Integrated Device Diagnostics Algorithm to Risk Stratify Heart Failure Patients - Results From the SCAN-HF Study.

Background: Integrated device diagnostics, Triage-HF, is useful in risk stratifying patients with heart failure (HF), but its performance for Japanese patients remains unknown. This is a prospective study of Japanese patients treated with a cardiac resynchronization therapy defibrillator (CRT-D), with a Medtronic OptiVol 2.0 feature.

Analysis of the driving mechanism in paroxysmal atrial fibrillation: comparison of the activation sequence between the left atrial body and pulmonary vein.

Background: It has been shown that most paroxysmal atrial fibrillation (AF) can be terminated by pulmonary vein (PV) isolation alone, suggesting that rapid discharges from PV drive AF. To define the driving mechanism of AF, we compared the activation sequence in the body of left atrium (LA) to that within PV.

Methods: Endocardial noncontact mapping of LA body (LA group; n = 16) and selective endocardial mapping of left superior PV (LSPV) (PV group; n = 13) were performed in 29 paroxysmal AF patients.

Clinical impact of successful recanalization for chronic total occlusion: insights from stress myocardial perfusion imaging.

The clinical benefits of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is still controversial. The purpose of this study is to assess the quantitative therapeutic benefits of successful PCI for CTO from the clinical data acquired by myocardial perfusion imaging (MPI). Consecutive 42 patients, who were successfully revascularized of CTO between August 2013 and March 2018, were examined.

Demonstration of the Anatomical Tachycardia Circuit in Sinoatrial Node Reentrant Tachycardia: Analysis Using the Entrainment Method.

Background The anatomical tachycardia circuit of sinoatrial node reentrant tachycardia (SANRT) has not been well clarified. This study aimed to elucidate the tachycardia circuit of SANRT. Methods and Results Exit and entrance of the intranodal sinoatrial node conduction (I-SANC) of the reentry circuit were identified in 15 SANRT patients.

Elongation of the high right atrium to coronary sinus conduction time predicts the recurrence of atrial fibrillation after radiofrequency catheter ablation.

Background: The impact of intra-atrial conduction delay on the recurrence of atrial tachyarrhythmia after radio frequency catheter ablation (RFCA) has not been fully elucidated.

Methods: We retrospectively analyzed 155 AF patients who were sinus rhythm at the start of RFCA. The conduction time from the onset of the earliest atrial electrogram at the high right atrium (HRA) to the end of the latest electrogram at the coronary sinus (CS) during sinus rhythm was defined as HRA-CS conduction time.

Clinical Significance of Brachial-Ankle Pulse Wave Velocity in Patients With Heart Failure With Reduced Left Ventricular Ejection Fraction.

Background: Although pulse wave velocity (PWV) is recognized to be a risk predictor for various cardiovascular diseases, the association of brachial-ankle PWV (baPWV) with cardiovascular outcomes in heart failure (HF) with reduced ejection fraction (HFrEF) patients remains uncertain.

Methods: We measured ankle-brachial pressure index (ABI) and baPWV values at stable condition after optimal therapy for HF in 201 consecutive HFrEF patients admitted to Kumamoto University Hospital from 2007 to 2015 who were enrolled and followed until the occurrence of cardiovascular events. We defined peripheral artery disease (PAD) as ABI value ≤ 0.

A retrospective study of arterial stiffness and subsequent clinical outcomes in cancer patients undergoing percutaneous coronary intervention.

Objective: Increasing attention is being paid to the relationship between cancer and cardiovascular diseases. In this study, we examined arterial stenosis and stiffness in patients with malignant diseases requiring percutaneous coronary intervention.

Methods: This was a retrospective, single-center, observational study.

Subdivision of the left ventricle by a discrete ridge and anomalous papillary muscle causing mid-ventricular obstruction: A case report.

A 16-year-old healthy boy visited our department because of a heart murmur. A 12-lead electrocardiogram showed left QRS axis deviation and repolarization abnormalities. Transthoracic echocardiography and a computed tomographic scan revealed a hypertrophied papillary muscle and a discrete ridge arising from the septal wall, causing mid-ventricular obstruction.

Analysis of the preferable site and stability of rotational reentry: its role for the maintenance of atrial fibrillation.

It remains unclear whether AF is maintained by rotor. We evaluated the significance of rotor during atrial fibrillation (AF). Prevalence, location, and stability of rotational reentry (RR) in the left atrium were clarified by endocardial non-contact mapping in 66 AF patients.

Coronary blood flow volume change is negatively associated with platelet aggregability in patients with non-obstructive ischemic heart disease who have no anti-platelet agents.

Background: Thrombus formation is one of the main pathogeneses of acute coronary syndrome with atherosclerotic rupture. Previous studies have reported that atherosclerosis increases platelet aggregability and that vascular endothelial dysfunction reflects early change of atherosclerosis. However, the relationship between coronary endothelial dysfunction and platelet reactivity remains unclear.

Serum Potassium and Cardiovascular Events in Heart Failure With Preserved Left Ventricular Ejection Fraction Patients.

Background: Although serum potassium (sK) levels are closely associated with the prognosis of chronic heart failure patients, the clinical significance of sK levels in cardiovascular outcomes of heart failure with preserved ejection fraction (HFpEF) patients is not fully understood.

Methods: This study was a retrospective, single-center, observational study. We enrolled 506 consecutive HFpEF patients admitted to Kumamoto University Hospital and divided them into four groups according to the quartiles of the sK levels at discharge (Q1: sK < 4.

Slow Potential at the Entrance of the Slow Conduction Zone in the Reentry Circuit of a Verapamil-Sensitive Atrial Tachycardia Originating From the Atrioventricular Annulus.

Background: Slow conduction zone in a verapamil-sensitive reentrant atrial tachycardia originating from atrioventricular annulus is composed of calcium channel-dependent tissue. We examined whether there was a slow potential (SP) at the entrance of the slow conduction zone.

Methods And Results: We first identified the pacing site from where manifest entrainment and orthodromic capture of the earliest atrial activation site were demonstrated in 40 atrioventricular annulus patients with atrioventricular annulus.

Analysis for the primary predictive factor for the incidence of esophageal injury after ablation of atrial fibrillation.

Background: Esophageal injury (EI) is a serious complication that occurs after catheter ablation of atrial fibrillation (AF), however predictable factor of EI is unclear.

Methods: Among 308 patients who underwent AF ablation, upper gastrointestinal tract endoscopy was performed the next day after ablation to examine for EI. To define the primary factor that predicts EI, patients' characteristics, number and amount of radiofrequency energy applied to the posterior wall, ablation procedure, and the shortest distance between esophagus and posterior left atrium measured on contrast computed tomography (SD-CT) were analyzed.

Outcome of current and history of cancer on the risk of cardiovascular events following percutaneous coronary intervention: a Kumamoto University Malignancy and Atherosclerosis (KUMA) study.

Aims: With the advancement in successfully treating different types of cancers, there is an immediate and increased need to focus on the risk and complexity of treating cardiovascular events in cancer survivors. This has led to the emergence of onco-cardiology/cardio-oncology field. We examined the varying incidence of cardiovascular events after percutaneous coronary intervention (PCI) in patients with or without cancer.

Study on the Effect of Irbesartan on Atrial Fibrillation Recurrence in Kumamoto: Atrial Fibrillation Suppression Trial (SILK study).

Background: Experimental studies suggest that angiotensin II-receptor blockers can influence atrial remodeling and may prevent atrial fibrillation (AF). Therefore, we hypothesized that irbesartan may prevent the recurrence of AF following either catheter ablation or electrical cardioversion of AF.

Methods: Study on the Effect of Irbesartan on Atrial Fibrillation Recurrence in Kumamoto (SILK study) is a prospective, multicenter, randomized, and open-label comparative evaluation of the effects of irbesartan and amlodipine on AF recurrence in hypertensive patients with AF who are scheduled to undergo catheter ablation or electrical cardioversion of AF.

Direct Oral Anticoagulants Form Thrombus Different From Warfarin in a Microchip Flow Chamber System.

Direct oral anticoagulants (DOACs) have low risk of intracranial hemorrhage compared to warfarin. We sought to clarify the different mechanisms responsible for suppression of bleeding events using the Total Thrombus-formation Analysis System (T-TAS), a flow-microchip chamber with thrombogenic surfaces. Blood samples were obtained at Off- and On-anticoagulant (trough) from 120 consecutive patients with atrial fibrillation (warfarin; n = 29, dabigatran; n = 19, rivaroxaban; n = 47, apixaban; n = 25), which were used for T-TAS to compute the area under the curve (AUC) (AR-AUC) in the AR chip, and to measure plasma concentrations of DOACs at On-anticoagulant.

Prevalence and mechanism of rotor activation identified during atrial fibrillation by noncontact mapping: Lack of evidence for a role in the maintenance of atrial fibrillation.

Background: It remains unclear whether atrial fibrillation (AF) is maintained by the rotor.

Objective: We evaluated the role of the rotor and examined its mechanism.

Methods: Among 75 patients with AF (60 paroxysmal, 15 persistent AF) who underwent 3-dimensional noncontact left atrial mapping during AF, we examined the prevalence and location of rotor activation and elucidated its mechanism.