Lead fracture

Patient

This 23-year-old woman received a dual chamber Lumax DR-T defibrillator after an episode of aborted sudden cardiac death. An event report (yellow color) was issued in the context of an episode de VF.

Main programmed settings

Single VF zone (280 ms)
24/30 cycles in the VF zone were needed for the diagnosis
Maximum sensitivity programmed at 0.5 mV
VF zone: ATP one shot, followed by 8 shocks of maximum strength (30 J)
Pacing mode: AAI at 70 bpm

Trace

Programmer tracing

atrial paced ventricular sensed rhythm;
ventricular extrasystole;
polymorphous ventricular arrhythmia detected in the VF zone;
episode of VF detected and charge of the capacitors;
end of the charge;
shock delivered (40 J, 65 Ohms) on the first VF classified cycle following the charge;
successful shock;
oversensing of a high-amplitude ventricular signal at the level of the sensing and shock channels initially following the R wave;
prominent increase in oversensing of the signals, no longer synchronized with QRS complexes;
oversensing persists, though the VF redetection counter (24/30 cycles) is not filled.

Comments

Lead fracture is revealed here after the detection of an episode of VF and the delivery of an electrical shock, which occasionally stretches the already taut lead as the patient is shocked, which might damage an already fragile lead. The shock was successful and its impedance was within normal limits. The pacing impedance, also normal before this episode, increased suddenly thereafter. The association of very short cycles and high impedance is clearly in favor of a lead rupture. This patient underwent extraction of the fractured lead and implantation of a new, ipsilateral lead.

Pacing & Defibrillation

ECG

Library

News

Lead fracture

Patient

Trace

Comments

Cardiocases

Legal information

Stimuprat editions