Implantable Cardioverter Defibrillator (ICD) systems have been shown to provide lifesaving therapy for patients at risk of sudden cardiac death due to ventricular tachyarrhythmia. In order to assure an ICD system is operating properly, some models of ICDs perform periodic system checks. The Patient Alert™ feature, in Medtronic® ICDs, monitors and alerts patients, via audible tones, to system integrity issues that have the potential to comprise patient safety. The objective of this research was to evaluate: how often patients are being alerted to ICD system issues, and how effective the alerts are at bringing patients into medical clinics for treatment and thus promoting patient safety. An analysis of 14,092 ICDs revealed that the probability of first alert occurrence increased with time since implant, but overall occurrence rates remained low (< 7% per patient year). The average median time from the alert sounding until the patient received medical attention was 4.3 days. Overall, for a life-threatening condition such as ICD therapy delivery being turned off, the majority (76%) of patients with this alert were brought into a clinic within one week to have therapy delivery turned back on. To reach the remaining patients, as well as bring all patients in quicker to seek medial treatment, additional communication modalities are being planned for the next generation of ICD systems.
Novel Ventricular Tachyarrhythmia Detection Enhancement Detects Undertreated Life-Threatening Arrhythmias
