【OBJECTIVES】This study aimed to investigate the clinical characteristics of young patients with Brugada syndrome（BrS）with ventricular septal defect（VSD）and explore their genetic backgrounds.【BACKGROUND】VSD is the most frequently occurring congenital heart disease among children. In contrast, BrS is a rare hereditary disease that is responsible for ventricular fibrillation and sudden cardiac death. Owing to their low incidence, the genetic background and clinical characteristics of patients with BrS with VSD have not been elucidated yet.【METHODS】This study enrolled 36 individuals who were diagnosed with BrS when they were＜20 years of age and performed genetic screening for SCN5A. The functional alteration in mutant Naþ channels was confirmed by patch clamp technique.【RESULTS】Among the 36 patients with BrS, 5 had been diagnosed with VSD. This study found 14 heterozygous SCN5A variants in 15 unrelated patients. The 5 patients with VSD carried SCN5A variants, including R367S, R535^＊, R893C, W1345C, and G1743R. The 3 missense variants（R893C, W1345C, and G1743R）have been proved to reduce peak Na⁺ current to＜10％. A functional analysis of SCN5A R367S was performed and the variant was found to be nonfunctional.【CONCLUSIONS】This study identified 5 loss-of-function SCN5A variants in 5 young patients with BrS with VSD. The study hypothesizes that altered blood flow in the right ventricular outflow tract leads to fibrosis and electrophysiological changes, predisposing the patients to earlier clinical presentation of BrS. In patients with VSD and ST-segment elevation in the right precordial leads, BrS should be considered and appropriate screening should be pursued accordingly.

Electrical storm attributed to ventricular fibrillation（VF）after myocardial infarction is a life-threatening condition that necessitates multiple defibrillations. Catheter ablation is a potentially effective treatment strategy for VF storm refractory to optimal medical treatment. The ablation strategy is to eliminate the Purkinje-related ectopic focus that frequently originates from the scar border zone at the left ventricular septum. The dominant domain of VF triggers may provide roadmaps for ablation to target the specific culprit regions in sinus rhythm. It should be kept in mind that ablation targeting the Purkinje network at the left ventricular septum carries a potential risk of damaging the His-Purkinje system, which must lead to the difficulty in heart failure management after the ablation procedure. Catheter ablation was acutely effective in suppressing VF storm in most cases. However, uncontrollable VF storm resulted in a high risk of subsequent death, and time from the beginning of the VF storm to catheter ablation was associated with acute mortality. When patients survived a VF storm after ablation, VF storm recurred over the long follow-up period in a few cases. However, a steady increase in mortality due to both cardiovascular and non-cardiovascular reasons was noted, underscoring the importance of careful management globally beyond the use of catheter ablation.

The time interval from left ventricular（LV）pacing to the earliest onset of QRS（S-QRS）is associated with local tissue property and an electrical latency of S-QRS≥37ms has been previously proposed as an independent predictor of mechanical response to cardiac resynchronization therapy（CRT）. This study sought to evaluate the prognostic value of S-QRS for long-term clinical outcomes in patients undergoing CRT. We included 82 consecutive heart failure（HF）patients with reduced LV ejection fraction（≤35％）, and a wide QRS complex（≥120ms）who underwent CRT. Patients were divided into a Short S-QRS group（＜37ms, SS-QRS）and a Long S-QRS group（≥37ms, LS-QRS）. The primary endpoint was total mortality including LV assist device implantation or heart transplantation, whereas the secondary endpoint was total mortality or HF hospitalization. S-QRS was 25.9±5.3ms in SS-QRS and 51.5±13.7ms in LS-QRS（p＜0.01）, and baseline QRS duration and electrical activation at the LV pacing site（i.e. Q-LV）were similar. During mean follow up of 44.5±21.1 months, 24 patients（29％）reached the primary endpoint, while the secondary endpoints were observed in 47 patients（57％）. LS-QRS had significantly worse event-free survival for both endpoints. LS-QRS was an independent predictor of total mortality（HR=2.6, 95％ CI=1.11 to 6.12, p=0.03）and the secondary composite events（HR=2.4, 95％CI=1.31 to 4.33, p＜0.01）. S-QRS≥37ms at the LV pacing site was a significant predictor of total mortality and HF hospitalization. S-QRS guided optimal LV lead placement is critical in CRT patients.

The number of CIEDs patients, who receive remote monitoring（RM）, has been increasing in Japan. There have been few reports of “remote monitoring dropouts” in which remote monitoring has to be discontinued for some reason and patients are forced to switch to conventional outpatient care only. The aim of this study was to clarify the incidence and factors about dropouts of RM and to investigate the predictors of such dropouts. Three hundred thirty-six consecutive patients（age : 77［70, 82］ years, male : 52.7％, pacemaker : 69.6％）who received remote monitoring after de novo CIEDs implantation or battery replacement between January 2018 and September 2021 were retrospectively studied. Factors associated with dropout of remote monitoring were analyzed. Of the 336 patients, 28（8.3％）had dropout of remote monitoring. The most common reason was communication failure caused by power supply or installation location（39.3％）. The dropout group was significantly older（83［74, 88］vs. 76［70, 81］, p=0.001）, and had a higher proportion of women（71.4％ vs. 45.1％, p=0.013）and replacement cases（46.4％ vs. 18.8％, p=0.001）than the continuation group. Multivariate logistic regression analysis showed that age（Odds ratio : 1.04, 95％ confidence interval : 1.00-1.09, p=0.044）and replacement case（Odds ratio : 3.73, 95％ confidence interval : 1.64-8.44, p=0.002）were independently associated with dropout of remote monitoring. In CIEDs patients, elderly patients and replacement cases may pose a higher risk of dropout of remote monitoring.