Multicenter Experience With a Bipolar Tined Polyurethane Ventricular Lead

Abstract

A multicenter study was undertaken to determine the failure rate of a specific bipolar tined polyurethane ventricular pacing lead, the Medtronic 4004/4004M pacing lead. Seven centers in the United States and Canada implanted 586 Medtronic 4004/4004M pacing leads. The study was designed to determine the probability and clinical manifestations of lead failure. Only failures compatible with an insulation problem were included. The Kaplan-Meier estimate of the percentage of 4004/4004M lead failures within 4 years after implantation was 14.1% (95% confidence interval: 8.5%-19.3%). Failures were manifested as sensing abnormalities, failure to capture, early battery depletion, and significant decrease in measured impedance compared with previous impedance measurements. The observed rate of failure is unacceptable, and strong consideration should be given to replacing the 4004/4004M pacing lead in pacemaker dependent patients and closely monitoring nondependent patients.

Application of Radiofrequency Energy in Surgical and Interventional Procedures:

“…Various complications associated with system malfunctions have been reported including macro and micro dislocation, lead or connector fracture, loose electrode connections, or insulation defects 15–19 . Previous studies suggest that lead insulation material has a major impact on electrode durability, but different investigations led to controversial results concerning the superiority of silicone or polyurethane 20–22 . Despite these differences, it seems to have been proven that high electrode failure rates up to 14% result during long‐term follow‐up more or less always associated with inappropriate therapy delivery due to artifact sensing 17 , 20 .…”

“…Previous studies suggest that lead insulation material has a major impact on electrode durability, but different investigations led to controversial results concerning the superiority of silicone or polyurethane 20–22 . Despite these differences, it seems to have been proven that high electrode failure rates up to 14% result during long‐term follow‐up more or less always associated with inappropriate therapy delivery due to artifact sensing 17 , 20 . An example reported by Seifert et al 23 describes the induction of ICD therapies caused by an electric razor, whereby in this case an insulation defect of the sensing electrode was presumed.…”

Performance of a Ventricular Automatic‐Capture Algorithm in a Wide Clinical Setting

“…PM dependence was assessed on the basis of the PM automatic algorithm for intrinsic rhythm search. Although there is no standardized definition of “pacemaker dependence” in permanent PM recipients, several reports 16 have defined PM dependence as the absence of any intrinsic rhythm for 30 seconds after PM programming at the lowest rate (30–40 ppm). The automatic algorithm in the Insignia PM searches for R‐wave for 10 seconds at a programmed lower rate of 30 ppm.…”

“…Even though no major clinical events were found in patients experiencing backup pacing during follow‐up, our study did not assess the safety of the AC feature by performing any additional test, such as electrocardiogram Holter monitoring, to verify the capture of backup pulses, or evidence fusion phenomenon interfering with ER. In addition, the follow‐up duration was too short to evaluate long‐term efficacy, even though the lead reaches maturity a few weeks after implantation 16 . Finally, the number of PM‐dependent patients (14%) and the overall percentage of replacements (13%) were low in comparison with the population enrolled.…”

Multi‐Center Clinical Experience with a Lumenless, Catheter‐Delivered, Bipolar, Permanent Pacemaker Lead: Implant Safety and Electrical Performance

“…To satisfy clinical demands for reduced diameter in implantable pacemaker leads, manufacturers introduced co‐radial or co‐axial arrangement of conductor coils, as well as different insulation materials that allow for reduction of insulation thickness 1–4 . While these improvements did not require a change in the implant or extraction procedure, they exposed the vulnerability to electrical insulation failure at stress sites such as the first rib and clavicle junction, the suture tie‐down area, where the lead is coiled in the generator pocket, and where the lead bends sharply 5–8 …”