Machine Learning-Based Clustering Using a 12-Lead Electrocardiogram in Patients With a Implantable Cardioverter Defibrillator to Identify Future Ventricular Arrhythmia.

Background: Implantable cardioverter defibrillators (ICDs) reduce mortality associated with ventricular arrhythmia in high-risk patients with cardiovascular disease. Machine learning (ML) approaches are promising tools in arrhythmia research; however, their application in predicting ventricular arrhythmias in patients with ICDs remains unexplored. We aimed to predict and stratify ventricular arrhythmias requiring ICD therapy using 12-lead electrocardiograms (ECGs) in patients with an ICD.

Machine Learning for Multi-Vessel Coronary Artery Disease Prediction on Electrocardiogram Gated Single-Photon Emission Computed Tomography.

: Single-photon emission computed tomography (SPECT) encounters difficulties in diagnosing severe multi-vessel coronary artery disease (svMVD) because of balanced ischemia. We estimated the predictive value of electrocardiogram-gated SPECT for svMVD and improved it using machine learning (ML). : We enrolled consecutive 335 patients (median age, 74 years; 255 men) who underwent adenosine stress-gated SPECT (Technesium) and coronary angiography.

Risk prediction of inappropriate implantable cardioverter-defibrillator therapy using machine learning.

We aimed to develop machine learning-based predictive models for identifying inappropriate implantable cardioverter-defibrillator (ICD) therapy. Our study included 182 consecutive cases (average age 62.2 ± 4.

Machine learning of microvolt-level 12-lead electrocardiogram can help distinguish takotsubo syndrome and acute anterior myocardial infarction.

Background: Qualitative differences in 12-lead electrocardiograms (ECG) at onset have been reported in patients with takotsubo syndrome (TTS) and acute anterior myocardial infarction (Ant-AMI). We aimed to distinguish these diseases by machine learning (ML) approach of microvolt-level quantitative measurements.

Methods: We enrolled 56 consecutive patients with sinus rhythm TTS (median age, 77 years; 16 men), and 1-to-1 random matching was performed based on age and sex of the patients.

Prognostic value of transient conduction disturbance in out-of-hospital cardiac arrest.

Aim: A retrospective observational study to verify the impact of electrocardiograms (ECGs) following out-of-hospital cardiac arrest (OHCA) on mortality.

Methods: We retrospectively studied 101 OHCA patients who achieved a return of spontaneous circulation (ROSC) and survived for ≥3 h. Among them, 50 patients (66 ± 17 years; 22 male) were evaluated using 12-lead ECGs repeatedly and were included in the final analysis: immediately after ROSC (initial ECG) and after the initial evaluation in the emergency department (second ECG).

Left ventricular end-systolic contractile entropy can predict cardiac prognosis in patients with complete left bundle branch block.

Background: Several patients with complete left bundle branch block (CLBBB) show left ventricular (LV) dyssynchrony and poor cardiac prognosis. However, the prognostic value of LV end-systolic contractile entropy which was measured by single-photon emission computer tomography (SPECT) has not been elucidated in patients with CLBBB.

Methods And Results: We recruited consecutive 115 sinus-rhythm patients with CLBBB who underwent ECG-gated TlCl-SPECT.

Characteristics of Marshall bundle-related atrial tachycardias using an ultrahigh-resolution mapping system.

Purpose: Marshall bundle (MB)-related atrial tachycardias (ATs) have already been described; however, their characteristics using an ultrahigh-resolution mapping system are not yet well known. The purpose of this study was to clarify the characteristics of MB-related ATs with ultrahigh-resolution mapping.

Methods: In 28 patients who underwent an electrophysiological study for ATs using an ultrahigh-resolution mapping system, precise circuits of 37 ATs were detected.

True complete left bundle branch block reveals dyssynchrony evaluated by semiconductor single-photon emission computed tomography.

Background: Conventional complete left bundle branch block (CLBBB) criteria sometimes result in a false-positive diagnosis that does not represent dyssynchrony. Recently, true CLBBB criteria have been proposed to detect responders to cardiac resynchronization therapy (CRT), although their correlation with severity of dyssynchrony or natural prognosis is unclear.

Methods: Ninety-four consecutive patients (74 ± 9 years, 63 men) with conventional CLBBB during sinus rhythm underwent semiconductor SPECT.

Characteristics of ventricular intracardiac electrograms of ventricular tachycardias originating from the epicardia in patients with an implantable cardioverter defibrillator.

Introduction: While characteristic waveforms of 12-lead electrocardiograms have been reported to predict the epicardial origin of ventricular tachycardia (VT), it has not been fully examined whether ventricular intracardiac electrograms (VEGMs) recorded from the implantable cardioverter defibrillator (ICD) via telemetry can determine the origin of VT or not. The aim of this study was to investigate the VEGM characteristics of VT originating from the epicardia.

Method And Results: Intracardiac VEGMs of the induced VTs, with detected sites of origin during the VT study, were recorded in 15 (23 VTs) of the 46 patients.

PR deviation as a risk marker for cardiac events in patients with Takotsubo syndrome.

Background: PR segment deviation (PRD: defined as PR elevation in aVR and PR depression in lead II/III) on electrocardiography is frequently observed in patients with acute pericarditis; however, there have been few studies that explore the occurrence of PRD in patients with Takotsubo syndrome (TTS). The clinical significance of PRD in TTS is not clearly elucidated.

Methods & Results: A total of 52 consecutive patients with TTS in sinus rhythm (73.

Ventricular Fibrillation Induced by Coronary Vasospasm in a Patient with Early Repolarization and Hyperthyroidism.

Vasospastic angina (VSA) has been recognized as a cause of ventricular fibrillation (VF) degenerating into sudden cardiac death. We experienced a case of VSA with hyperthyroidism in which VF was provoked with an augmented J-wave amplitude in the inferior leads. The patient underwent insertion of an implantable cardioverter-defibrillator for the secondary prevention of VF in addition to taking Ca-channel antagonists.

Combination of hemoglobin and low-flow duration can predict neurological outcome in the initial phase of out-of-hospital cardiac arrest.

Purpose: To predict neurological outcome following out-of-hospital cardiac arrest (OHCA) using a combination of hemoglobin (Hb) and low-flow duration (LFD).

Materials And Methods: We retrospectively examined 131 patients (75 ± 13 years, 64 men) with return of spontaneous circulation (ROSC) following non-traumatic OHCA. The LFD was the duration from the start of cardiopulmonary resuscitation to ROSC.

Development of Nonpulmonary Vein Foci Increases Risk of Atrial Fibrillation Recurrence After Pulmonary Vein Isolation.

Objectives: The aim of this paper was to clarify the impact of nonpulmonary vein foci (NPVF) on atrial fibrillation (AF) recurrence after pulmonary vein (PV) isolation.

Background: NPVF are considered contributing factors for the recurrence of AF after PV isolation, but their exact role remains unclear.

Methods: We retrospectively reviewed 216 patients (paroxysmal AF, n = 172; persistent AF, n = 44) who underwent a second electrophysiological study 6 months after the original PV isolation.

Ventricular tachycardia storm originating from interventricular septum successfully treated with surgical cryoablation with electroanatomic and electrophysiological mapping before dual valve replacement.

A 58-year-old man with dilated cardiomyopathy was admitted with heart failure. He had a history of two catheter ablation procedures for ventricular tachycardia (VT) originating from the intraventricular septum (IVS). Before dual valve replacement (DVR), he suffered a VT storm.

Life-threatening arrhythmias leading to syncope in patients with vasospastic angina.

The coronary artery diseases (CAD) that can lead to the occurrence of a syncopal attack include acute coronary syndrome, vasospastic angina, effort angina, and prior myocardial infarction. The possible mechanisms considered to lead to syncope in patients with CAD are pump failure, tachyarrhythmia, bradycardia, and vagal stimulation. Coronary artery spasm, in particular, is occasionally observed in patients with unexplained syncope in Japan.

Effectiveness of Bare Metal Stent Implantation for the Treatment of Coronary Artery Aneurysm: A Multimodality Imaging Evaluation.

Coronary artery aneurysm (CAA) after sirolimus-eluting stent (SES) implantation is one of the most troublesome problems associated with first-generation drug-eluting stents. However, the natural course and standard therapy of CAA has been unknown. A 49-year-old man underwent SES implantation for the left anterior descending artery.

Usefulness of epicardial impedance evaluation for epicardial mapping and determination of epicardial ablation site for ventricular tachycardia: A pilot study.

Background: During epicardial mapping, determination of appropriate ablation sites in low voltage areas (LVA) is challenging because of large epicardial areas covered by adipose tissue.

Objective: To evaluate the impedance difference between epicardial fat and the epicardial LVA using multiple detector computed tomography (MDCT).

Methods: We enrolled patients who underwent ventricular tachycardia (VT) ablation via the epicardial approach after endocardial ablation failure.

Outcomes of Brugada Syndrome Patients with Coronary Artery Vasospasm.

Objective To evaluate the outcomes of patients with concomitant Brugada syndrome and coronary artery vasospasm. Methods Patients diagnosed with Brugada syndrome with an implantable cardiac defibrillator were retrospectively investigated, and the coexistence of vasospasm was evaluated. The clinical features and outcomes were evaluated, especially in patients with coexistent vasospasm.

Life-Threatening Ventricular Arrhythmia and Brugada-Type ST-Segment Elevation Associated With Acute Ischemia of the Right Ventricular Outflow Tract.

Background: Brugada-type ECG (Br-ECG) is occasionally observed during acute myocardial ischemia of the right ventricular outflow tract (RVOT). No studies have explored, however, the association of ventricular tachyarrhythmia and development of Br-ECG due to acute ischemia of the RVOT.

Methods and results: The study included 13 consecutive patients with acute ischemia of the RVOT during coronary catheterization.

Clinical Characteristics and Long-Term Prognosis of Senior Patients With Brugada Syndrome.

Objectives: This study investigated clinical characteristics and prognosis of Brugada syndrome (BrS) in patients older than 60 years of age during a long-term follow-up period.

Background: Clinical characteristics and prognosis of senior patients with BrS have not been clearly elucidated.

Methods: A total of 181 patients with BrS were divided into 2 groups by age at the time of diagnosis: the younger group was <60 years of age (n = 123), and the senior group was ≥60 years of age (n = 58).

Long-term efficacy of catheter ablation for paroxysmal atrial fibrillation in patients with Brugada syndrome and an implantable cardioverter-defibrillator to prevent inappropriate shock therapy.

Background: In patients with an implantable cardioverter-defibrillator (ICD) and Brugada syndrome (BrS), the long-term efficacy of catheter ablation for preventing inappropriate shock therapy due to paroxysmal atrial fibrillation (PAF) has not been elucidated.

Objective: To evaluate the efficacy of atrial fibrillation (AF) ablation for PAF for prevention of inappropriate ICD therapy over a longer follow-up period.

Methods: We enrolled 76 men with BrS and an ICD, with a mean age of 46.