Summary version
A 68-year-old patient with ischemic cardiomyopathy was admitted for a single-chamber implantable cardioverter-defibrillator (ICD) generator replacement after normal battery depletion. He was implanted in 2001 with a dual-coil lead (Sprint Quattro, Medtronic) and a Medtronic Gem 7227 device in secondary prevention. After connection of the new generator (Protecta XT VR, Medtronic), shock impedances of the ICD lead measured with subthreshold test pulses were normal (see figure). After defibrillation testing (DT), shock impedances were abnormal (>200 Ω). A screw problem was excluded, and a new defibrillation lead (Sprint Quattro Secure S6935, Medtronic) was implanted with normal shock impedance (71 Ω) and successful DT. This case highlights the importance of DT to identify ‘concealed’ high-energy lead dysfunction, especially in old leads.
Funding
S.S.B. was funded by EHRA (Advanced training fellowship programme).
The full-length version of this report can be viewed at: http://www.escardio.org/communities/EHRA/publications/ep-case-reports/Documents/defibrillation-testing-concealed-lead-fracture.pdf
