Two Distinct Atrial Breakthroughs During Fast-Slow Atrioventricular Nodal Reentrant Tachycardia.

Introduction: The slow atrioventricular nodal pathway (SP) typically has a single atrial breakthrough site.

Methods And Results: We report a case of fast-slow type AVNRT with two distinct atrial breakthrough sites during tachycardia. The earliest atrial activation site (EAAS) was at the right inferior septum, followed by the inferolateral wall of the tricuspid annulus.

Atypical atrial resetting with ventricular extrastimulus during tachycardia: What is the mechanism?

This atypical atrial resetting with ventricular extrastimulus delivered during supraventricular tachycardia is characterized by no capture of local ventricular deflection contralateral to the earliest atrial site and is a finding unmasking the presence of a nodoventricular pathway, the ventricular insertion of which is located apically, away from the mitral annulus.

Novel Q234K variant, identified in patients with long QT syndrome and epileptiform activity, induces both gain- and loss-of-function of slowly activating delayed rectifier potassium currents.

Introduction: KCNQ1 and KCNE1 form slowly activating delayed rectifier potassium currents (I). Loss-of-function of I by variants causes type-1 long QT syndrome (LQTS). Also, some variants are reported to cause epilepsy.

Fast-slow atrioventricular nodal re-entrant tachycardia incorporating superior and inferolateral left atrial slow pathways.

Background: A 70-year-old man revealed a rare type of atrioventricular nodal re-entrant tachycardia (AVNRT) involving distinct retrograde pathways, superior slow pathway, and inferolateral left atrial slow pathway.

Result: Radiofrequency ablation was successfully performed on the noncoronary cusp and in the left atrium, respectively, to eliminate the tachycardias.

Discussion And Conclusion: Due to the anomalous electrical conduction patterns, careful diagnosis and ablation strategies were necessary to avoid the risk of atrioventricular block.

Ventriculoatrial Block and His-His Changes During Supraventricular Tachycardia: Diagnostic and Mechanistic Implications.

Supraventricular tachycardia (SVT) with ventriculoatrial (VA) block can represent a diagnostic challenge. We present a case of SVT where His-His interval shortening was repeatedly observed during episodes of VA block. This novel observation is more diagnostically suggestive of atrioventricular nodal re-entrant tachycardia, as opposed to orthodromic re-entry using a nodofascicular or nodoventricular pathway where a constant His-His is recorded during episodes of VA block.

Oozing-type rupture caused by right ventricular intramural hematoma after right ventricular infarction.

Unlabelled: An 81-year-old man was admitted to the hospital because of decreased level of consciousness. He had bradycardia (27 beats/min). Electrocardiography showed ST-segment elevation in leads II, III, and aVF and ST-segment depression in leads aVL, V1.

Atrioventricular Ring Tachycardias: Atypical Fast-Slow Atrioventricular Nodal Reentrant Tachycardia and Atrial Tachycardia Share a Common Arrhythmogenic Substrate-A Unifying Proposal.

Our understanding of the variants of slow pathway (SP) and associated atypical atrioventricular (AV) nodal reentrant tachycardia (NRT) is still growing. We have identified variants extending outside Koch's triangle along the tricuspid annulus, including superior, superoanterior and inferolateral right atrial SP and associated atypical, fast-slow AVNRT. We review the history of each variant, their electrophysiological characteristics and related atypical AVNRT, and their treatment by catheter ablation.

Efficacy of SubcutAneous implantable cardioVErter-defibrillators in ≤18 year-old CHILDREN: SAVE-CHILDREN registry.

Background: In adult patients, subcutaneous implantable cardioverter defibrillators (S-ICDs) have been reported to be non-inferior to transvenous ICDs with respect to the incidence of device-related complications and inappropriate shocks. Only a few reports have investigated the efficacy of S-ICDs in the pediatric field. This study aimed to investigate the utility and safety of S-ICDs in patients ≤18 years old.

Novel CACNA1C R511Q mutation, located in domain Ⅰ-Ⅱ linker, causes non-syndromic type-8 long QT syndrome.

Background: Gain-of-function mutations in CACNA1C encoding Cav1.2 cause syndromic or non-syndromic type-8 long QT syndrome (LQTS) (sLQT8 or nsLQT8). The cytoplasmic domain (D)Ⅰ-Ⅱ linker in Cav1.

Discrimination of atypical atrioventricular nodal reentrant tachycardia from atrial tachycardia by the V-A-A-V response.

Introduction: The electrophysiological discrimination between fast-slow (F/S-) atrioventricular (AV) nodal reentrant tachycardia (NRT) and atrial tachycardia (AT) originating from the interatrial septum remains challenging. While a V-A-A-V response may occur immediately after ventricular induction or entrainment of either tachycardia, the electrophysiological dissimilarities in that response between the two tachycardias remain unclear. The purpose of this study was to identify a diagnostic indicator discriminating F/S-AVNRT from AT by examining the difference in the V-A-A-V response between the two tachycardias.

Acute myocarditis associated with COVID-19 vaccination: A case report.

Recently, new vaccine platforms-including mRNA vaccines for coronavirus disease 2019 (COVID-19) have been given emergency use authorization in Japan. Here, we present a rare case of myocarditis following a COVID-19 vaccine. In this case, myocarditis was confirmed by cardiac magnetic resonance imaging, endomyocardial biopsy, and troponin levels.

Safety verification of carbon-ion radiotherapy for patients with cardiac implantable electronic devices (CIEDs).

According to guidelines, carbon-ion beam therapy is considered to carry a high safety risk for patients with cardiac implantable electronic devices (CIEDs), although the actual impacts remain unclear. In this study, we investigated the safety of carbon-ion beam therapy in patients with CIEDs. Patients with CIEDs who underwent carbon-ion therapy at Gunma University Heavy Ion Medical Center between June 2010 and December 2019 were identified and investigated for abnormalities in the operation of their CIEDs, such as oversensing and resetting during irradiation, and abnormalities in operation after treatment.

Pacing site- and rate-dependent shortening of retrograde conduction time over the slow pathway after atrial entrainment of fast-slow atrioventricular nodal reentrant tachycardia.

Introduction: We tested our hypothesis that atrial entrainment pacing (EP) of a) the common-type (com-) fast-slow (F/S-) atypical atrioventricular nodal reentrant tachycardia (AVNRT) using a typical slow pathway (SP), or b) the superior-type (sup-) F/S-AVNRT using a superior SP, both modify the retrograde conduction time across the SP immediately after termination of EP (retro-SP-time).

Methods: We measured the difference in the His-atrial interval (HA difference) immediately after cessation of EP, performed at 2 ± 2 rates from the high right atrium (HA[1]-HRA) versus from the proximal coronary sinus (HA[1]-CS) in 17 patients with com-F/S-AVNRT and 11 patients with sup-F/S-AVNRT. We also measured the atrial-His and HA intervals of the first and second cycles immediately after cessation of EP and during stable tachycardia.

Unilateral Lung Congestion During Exercise in a Patient With a Single Pulmonary Vein Stenosis.

A 55-year-old man underwent exercise stress echocardiography for evaluation of left inferior pulmonary vein stenosis. During exercise, ultrasound B-lines developed in the left lung only. Unilateral pulmonary congestion did not lead to forward or backward failure.