Lead dysfunction

Programmer Screen

→ Figure 1

Warning screen

→ Figure 2

Your turn

What does this signify?

1. RV lead conductor fracture
2. RV lead insulation breach
3. Episodes of ventricular arrhythmia

→ Figure 3

Rate interval plot

• We see a cloud of ventricular intervals which is non-physiological
• Also intervals over 400 beats per minute are highly unlikely to be physiological
• Various diagnoses are made by the ICD: there are multiple diagnoses of SVT/ST, VF and SR

EGM

• The underlying rhythm is sinus rhythm with spontaneous atrial events (As) conducted to the ventricule (Vs)
• The ventricular channel is saturated with artefacts; they are very sharp signals with varying amplitudes and cycle lengths
• The VF counter is filled but resets because of diagnosis of SVT/ST
• The VF counter is then filled with maintenance of the VF majority and charge of the capacitors (C markers)
• We already know from the Overview screen that no therapies were delivered during any episode

EGM 2 (older episode)

→ Figure 4

• This episode was registered a week before the first shown EGM
• It is a similar tracing with detection of VF and charge of the capacitors
• Also here, the noise stops during the charge and the charge is aborted
• This episode is shorter than the episode a week later; which shows a process often seen in lead failure, progressive prolongation of noise. Noise progression towards inaproppriate therapies may occur within 24 hours but it may also take days, weeks or even months.

Correct answer – n° 2