Inappropriate ICD therapy due to lead-related noise in an active fixation ICD lead.
BACKGROUND
Despite advances in technology, problems with effective ventricular endocardial sensing continue to arise and to result in inappropriate implantable cardioverter defibrillator (ICD) therapies.


RESULTS
The patient is a 79-year-old man with ischemic cardiomyopathy and ventricular tachycardia (VT) who received inappropriate ICD therapies due to lead-related noise detection. Noise was created by the distal helix, which was not fully deployed, intermittently contacting the internal guidepost of the lead (CPI, Guidant, model 0155). After the complete deployment of the helix the problem resolved and the pacing parameters remained stable.


CONCLUSIONS
To our knowledge, this is the first confirmed case report of non-physiologic sensing secondary to the incompletely deployed helix of an active fixation defibrillation lead. A design flaw with this lead led to its redesign to avoid noise over-sensing.
Mela
T
T
Cardiac Arrhythmia Service, Massachusetts General Hospital, 75 Fruit Street, Boston, MA 02114, USA. tmela@partners.org
Ngarmukos
T
T
Rosenthal
L
L
Mittleman
R
R
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000628:therapy; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004562:Electrocardiography; D006801:Humans; D008297:Male; D017180:Tachycardia, Ventricular / Q000209:etiology