[The intraoperative measured stimulation impedance of pacemaker electrodes is not a predictor for their longevity].
As pacing impedance is inversely related to pacing current, the increase of pacing impedance additionally decreases pacing current. Whether the impedance measurement at implantation predicts the outcome during follow-up, was studied in 87 patients who received the VDD-single lead UniPass 425 connected to the pacemaker Unity (Sulzer Intermedics). The impedance changes between implantation and 6 months follow-up were assessed for each patient. Similar impedance values were defined, if the two measurements were within a range < or = -100 to +100 omega. Six-months impedance was lower or higher compared to implantation, if the difference exceeded > -100 or > +100 omega. At implantation, impedance was 535 +/- 98 omega (range: 333-811 omega) and significantly increased to 604 +/- 160 omega (range: 361-1150 omega) after 6 months. Mean difference between the two measurements was 69 +/- 162 omega (range: -336 bis + 560 omega). Similar impedance had 43 (implantation: 527 +/- 75 omega, 6 months: 531 +/- 87 omega), lower values 11 (implantation: 660 +/- 83 omega, 6 months: 494 +/- 73 omega) and higher values 33 patients (implantation: 503 +/- 99 omega, 6 months: 735 +/- 168 omega). Compared to the patients with similar impedance patients with lower impedance had a significantly higher impedance values at implantation.


CONCLUSIONS
Pacing impedance increased significantly within 6 months after implantation. Pacing impedance changed > 100 omega in 51% of the patients. The long-term follow-up of pacing impedance can be predicted generally, but not for the individual patient.
Schuchert
A
A
Abteilung für Kardiologie Universitäts-Krankenhaus Eppendorf, Hamburg.
Schmidt
W
W
Jakob
M
M
Jung
W
W
Karmann
W
W
Kreuzer
J
J
Staedt
U
U
Stertmann
W A
WA
Treese
N
N
Meinertz
T
T
D000368:Aged; D000369:Aged, 80 and over; D017097:Electric Impedance; D004567:Electrodes, Implanted; D004868:Equipment Failure; D005500:Follow-Up Studies; D006327:Heart Block / Q000628:therapy*; D006801:Humans; D008875:Middle Aged; D010138:Pacemaker, Artificial
Die intraoperativ gemessene Stimulationsimpedanz von Schrittmacherelektroden ist kein Prädiktor für ihren Langzeitverlauf.