Implantable electrocardiographic monitoring—clinical experiences

Abstract

Summary Implantable cardioverter defibrillators (ICDs) are lifesaving in patients with an increased risk of sudden cardiac death. However, ICD treatment bears the burdens of being unpleasant and being technically troublesome. The 2 major issues discussed in relation to ICDs are the risks of technical malfunction and inappropriate shocks. Recent recalls by major ICD manufacturers have shown that safety is less than perfect after more than 20 years of thorough research. Therefore, it is of interest to monitor ICD parameters and transfer the data from the patient home to the clinic on a day-to-day basis. The possibility of data transmission serves both the purpose of early detection of device malfunction and the possibility of preventing inappropriate shocks. Data transmission from home also gives the possibility of reducing the number of follow-up visits. This is of increasing interest as the number of visits will grow substantially with the growth of the ICD population. It will be possible to focus the visits and minimize routine controls. Several data of interest can be transferred, for example, lead impedances, battery status and event counters. Implantation of devices with the possibility of data transmission from home can give specific benefits on the detection of, for example, early battery depletion, T-wave oversensing, lead failure, rise in the number of paced beats, accumulation of nonsustained ventricular tachycardias, and the evaluation of the appropriateness of treatment delivered by the ICD. Online transferal of event intracardiac electrocardiogram (IECG) offers a new possibility for early identification of inappropriate ICD detection of event heart rhythm and possible prevention of inappropriate shocks. The ICD can prevent sudden cardiac death and total