It was reported that a patient's m1000 device was showing high impedance at the patient's second visit following implantation surgery.Device history records were reviewed and the device passed all quality tests prior to distribution.X-rays were received.Per the x-rays, the generator placement appeared to be normal in the left axillary chest area.Complete lead pin insertion could not be assessed due to the angle and quality of the images provided.The feed-through wires appeared normal.The lead was observed in the neck and chest.Note that a portion of lead was routed behind the generator and so could not be assessed.The strain relief loop was present per labeling, however no strain relief bend was observed.One tie down was used to secure the strain relief.In the portions of the lead visible, no gross lead fractures or other anomalies were observed.Based on the images provided, no obvious cause for the high impedance was identified.Note that the presence of problems in obscured portions of the lead and microfractures cannot be ruled out.Internal investigation identified that a change in the timing of the impedance test may result in higher impedances for model 1000 generator compared to those reported by model 103-106 generator.As indicated in the physician¿s manual, high lead impedance (">/"=5300 ohms), in the absence of other device-related complications, is not an indication of a lead or generator malfunction.Existing recommendations, as described in the physician¿s manual, should still be followed.Additional investigation is underway.
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