Letter by Kleemann and Seidl Regarding Article, “Necessity for Surgical Revision of Defibrillator Leads Implanted Long-Term: Causes and Management”
To the Editor:
We read with great interest the article by Eckstein et al1 recently published in Circulation. They investigated the necessity for surgical revision of malfunctioning defibrillator leads and showed that in selected cases, simple implantation of an additional pace/sense lead was feasible. This article raises some issues about lead replacement management of implantable cardioverter-defibrillator (ICD) leads. It is remarkable that only 13 leads (34%) were replaced, although 9 leads had lead fractures, 10 had insulation defects, and 9 had artifact oversensing. The interesting question raised by the study is if it is sufficient to add a pace/sense lead when an insulation defect or noise problem is found and the integrity of the high-voltage part of the ICD lead is ascertained. In the study of Eckstein et al, it was sufficient to add only a pace/sense lead when the integrity of the high-voltage part of the ICD lead was confirmed. This approach carries a substantial risk for further lead-related problems, because lead defects can progress and probably involve the entire lead rather than only 1 component.2 If the ICD lead is not replaced, an accurate surveillance of the remaining lead, including the high-voltage part, is essential. However, in the present study, no information is provided about the outcome of the remaining ICD lead. Information about the integrity of the high-voltage part at the end of the follow-up is lacking. We don’t know how the performance of the remaining ICD lead was monitored and if regular defibrillation threshold testing was performed during follow-up. Lead impedance of the ICD lead is not always available during routine ICD interrogation depending on the implanted device. In addition, accurate surveillance of the high-voltage part of the ICD lead during follow-up would need defibrillation threshold testing, because the measurement of the lead impedance alone is not completely reliable. In our study, 2% of lead defects were only diagnosed by threshold testing during ICD replacement whereas the lead impedance tested before was within the normal range.3
Eckstein J, Koller MT, Zabel M, Kalusche D, Schaer BA, Osswald S, Sticherling C. Necessity for surgical revision of defibrillator leads implanted long-term: causes and management. Circulation. 2008; 117: 2727–2733.
Kleemann T, Becker T, Doenges K, Vater M, Senges J, Schneider S, Saggau W, Weisse U, Seidl K. Annual rate of transvenous defibrillation lead defects in implantable cardioverter-defibrillators over a period of >10 years. Circulation. 2007; 115: 2474–2480.