Clinical case

The patient was contacted and asked to come into the device clinic for a manual check-up. The 12-lead ECG showed ventricular escape rhythm and ventricular pacing spikes without capture. The patient had no new symptoms, NYHA II.

Interrogation

The overview screen shows abnormal sensing values for the RV, 0 episodes but multiple alerts (red button).

The alert list confirms the presence of the Lead Parameter Evaluation (LPE) alert based on changes in sensing amplitude, autothreshold and impedance. There is also an older alert for RV threshold only.

Lead Parameter Evaluation (LPE)

The Lead Parameter Evaluation (LPE) is a new algorithm which aims to enhance patient’s protection through earlier lead failure detection and alert. It is a multi-parametric algorithm which may trigger a red alert through an evaluation of daily lead checks (impedance, threshold, sensing) and other information (non treated VF episodes, short VV interval counter). In more detail, the electrical settings assess daily lead impedance, coil continuity, lead pacing threshold and lead sensing amplitude. The rhythmic settings assess the daily number of non-treated episodes in VF rate zone and the daily number of short ventricular intervals (<= 180ms) outside an episode in VF rate zone. The LPE issues a lead alert if 1 electrical setting is abnormal 3 days in a row, or 2 settings (electrical/electrical, or electrical/rhythmic) are abnormal in a 7-day window. This new algorithm was retrospectively tested with data coming from implanted previous Microport’s ICDs and CRTDs and has to be prospectively assessed.

This alert, which could be considered one of the most important alerts for ICD patients, should always be associated with a rapid response, ensuring the patient is secure and not at risk for inappropraite and/or ineffective therapies.

Clinical case, Lead trends

The lead trends show that since a few days, the lead parameters had been deteriorating with low sensed values, high/out-of-range pacing thresholds and decreasing impedance. In fact, an alert was already sent a few days prior due to impossibility to perform pacing threshold but review of the lead showed no other arguments for lead dysfunction at the time and careful remote evaluation was continued. Because of high suspicion of RV lead dysfunction, the therapies were deactivated and a chest X-ray was performed showing RA and RV lead displacement.

The next day, both leads were removed and new atrial and RV ICD leads were placed.