br Purpose br Methods Participating centers Forty main
Methods Participating centers: Forty main ICSD centers in Japan from Hokkaido to Okinawa, which cover approximately 20% of all new ICSD patients in Japan, are participating in the present study. After obtaining written informed consent, all patients (over 20 years old) will be registered, regardless of their underlying azilsartan medoxomil disease and regardless of the purpose (primary or secondary prevention) for using an ICSD. Data collection: From 2002, the JHRS began to collect ICSD patient data using website registration (termed Japanese cardiac defibrillator therapy registration, or JCDTR) . This larger study aims to collect data on and investigate the general parameters of patients with ICSD, such as clinical backgrounds of patients (age, gender, and underlying heart disease), purposes of indication (primary or secondary), complications during implantation procedures, and incidence of appropriate and inappropriate therapies from the ICSD (Table 1). Approximately 10,000 patients have been registered in this trial . The Nippon Strom Study was planned as a sub-study of the JCDTR focus on E-storms after ICSD implantation. All centers followed the national and international consensus guidelines for implantation of an ICD, either in the field of secondary prevention or in the field of primary prevention of sudden death for all possible cardiac substrates [15,16]. Follow-up data should be collected by each participating center at a maximum interval of 6 months. At the outpatient clinic, follow-up data are retrieved from the ICSD and written down on the follow-up data sheets. The medical staff can also request support from the CDR to complete these documents. The data are also sent to the JHRS office and submitted to the website by the office secretary. If a patient is using remote monitoring, data can also be transmitted electronically . Definition of E-storm: An E-storm was defined as 3 or more independent episodes that require appropriate ICD interventions (either antitachycardia pacing or shock therapy) to terminate the VT/VF within 24h . At least 3 apparent atrial conducted beats after ICD intervention are required to be recognized as successful termination of the VT/VF; in other words, if there are 3 or more atrial conducted beats and/or back-up pacing between the 2 consecutive VT/VF episodes, these are counted as “2 episodes”. With the aim of excluding inappropriate multiple therapy of an ICD from data analysis, electrocardiograms during the storm will be sent to the JHRS secretary and will be evaluated by several specialists in electrophysiology who do not participate in Nippon Storm registration. Data sample size: We aim to collect data for a large number of patients with ICSDs within the 27-month registration period, during which we expect to achieve registration of more than 1000 patients with ICSD and complete follow-up data collection according to previous implant performance at each center with the assumption of a 5–10% incidence of E-storms during the 2-year follow-up [19,20]. We will thus be able to obtain data for 50–100 cases of E-storms, and this large number of E-storm events will allow us to investigate the clinical profiles of patients who experience E-storms and the mechanism of E-storms.
Role of the funding source The Nippon Storm Study was organized by the JHRS and JSE and is partly supported by the Japanese Heart Foundation and Japanese Device Industry Association. There is no particular sponsor (device product company) that has had a role in the study design or conduct of the study, collection of data, analysis or interpretation of data, or preparation of the present manuscript. The corresponding author had full access to all of the data and takes full responsibility for the integrity of the data in this study as well as for the decision to submit this manuscript for publication.
Conflict of interest
Introduction T-wave oversensing in implantable cardioverter defibrillators remains a problem that requires a solution [1–5]. Although this phenomenon may be a manufacturer-related technical problem, several situations have been reported to cause or contribute to the onset of T-wave oversensing [6–16]. We report here a case of inappropriate shock administration that was caused by T-wave oversensing and that was induced by the patient\'s postural changes.