Detection and management of an implantable cardioverter defibrillator lead failure: incidence and clinical implications.
OBJECTIVE
This study evaluated the long-term reliability of an implantable cardioverter defibrillator (ICD) lead to determine the incidence, clinical presentation, and management of lead failure.


BACKGROUND
Despite recent advances in ICD technology, the long-term reliability of ICD leads remains a significant problem.


METHODS
Concern about long-term reliability of coaxial polyurethane ICD leads caused us to systematically study all patients implanted with Medtronic (Minneapolis, Minnesota) 6936 lead at our institution. We performed follow-up of 74 patients with 76 ICD leads that were implanted from February 28, 1995 to September 8, 1997. Thirty-seven patients underwent routine clinical ICD follow-up testing and ventricular fibrillation induction to determine the status of their ICD lead after a mean follow-up of 68.6 +/- 8.2 months.


RESULTS
The lead survival analysis shows a cumulative failure probability of 37% (confidence interval, 24% to 54%) at 68.6 months. Six patients demonstrated a previously undescribed mode of ICD lead failure: prolonged oversensing immediately after shock therapy. The use of short interval counters to monitor nonphysiologic R-R intervals and the measurement of ring-to-coil impedance detected early lead failures in five patients.


CONCLUSIONS
This analysis shows: 1) problems with ICD leads may not become apparent until late during follow-up and may become a significant late problem, 2) a "signature" mode of lead failure for the 6936 consisting of oversensing of electrical noise following shocks, 3) early detection of lead failure with a short interval counter algorithm or measurement of ring-to-coil impedance may be clinically useful.
Ellenbogen
Kenneth A
KA
Division of Cardiology, Medical College of Virginia/Virginia Commonwealth University, Richmond, Virginia 23398, USA. kellenbogen@pol.net
Wood
Mark A
MA
Shepard
Richard K
RK
Clemo
Henry F
HF
Vaughn
Tim
T
Holloman
Keith
K
Dow
Marlene
M
Leffler
Jeanne
J
Abeyratne
Athula
A
Verness
Dave
D
D000368:Aged; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D003935:Diagnostic Techniques, Cardiovascular; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D004868:Equipment Failure / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011140:Polyurethanes / Q000009:adverse effects; D011237:Predictive Value of Tests; D017180:Tachycardia, Ventricular / Q000628:therapy; D013997:Time Factors
D011140:Polyurethanes