Ventricular oversensing in 518 patients with implanted cardiac defibrillators: incidence, complications, and solutions

Intermittent failure of pacing output caused by algorithm to prevent T-wave oversensing

“…Intracardiac or extracardiac oversensing in the ICD population has an estimated prevalence of 7.9% 2 . Pacemaker-dependent patients are particularly vulnerable to far-field myopotential oversensing, with serious consequences such as syncope owing to inhibition of ventricular pacing or inappropriate shocks 3 .…”

Complications of Pacemaker Implantation

“…In some cases, inappropriate therapy delivery is described as potentially life-threatening (Kiviniemi et al, 1999), especially when the shock falls in the vulnerable phase of QRS complex, triggering ventricular tachycardia or ventricular fibrillation (VF). Rauwolf et al (2007) evaluated in a large cohort of 518 ICD patients the incidence and various types of ventricular oversensing (VO), the occurrence of inappropriate shock deliveries as well as the frequency of complications requiring invasive procedures to solve VO during a long-term follow-up. The most frequent oversensing mechanism was observed as T-wave oversensing in 10 patients, 8 (1.5%) patients were noticed with VO due to myopotentials; 5 patients suffered from VO due to electrode failure and consecutive noise sensing with inadequate therapy delivery.…”

Oversensing of a Particular Transient Noise Appearing After the Implantation of an Implantable Cardiac Device

“…Extracardiac noise has many possible causes, such as EMI, myopotentials, lead fractures, and connector (header, adapter, or set screw) prob-lems, and it is difficult to identify the origin of the noise in individual cases. 3,4) We experienced cases in which failure of the ventricular pacing occurred with the pacemaker. We also observed an episode in a patient with an ICD in whom oversensing occurred after transient noise in the acute phase after the implantation.…”