Stability of pacing indices and need for pacing in cardiac transplant patients over 1 year of follow-up.
BACKGROUND
A significant minority of cardiac transplant patients require permanent pacemaker (PPM) implant, primarily for sinus node dysfunction. The stability of pacing indices has not been determined in this unique patient population, and data regarding ongoing need for pacing are limited.


METHODS
Pacing indices (sensing, threshold, and impedance) as well as the percentage of time patients required pacing were recorded, from 30 cardiac transplant patients that underwent PPM implant, over 1 year of follow-up. Repeated measure ANOVA (analysis of variance) was used to compare pacing indices and the percentage of time patients required pacing in each cardiac chamber (right atrium (RA) and right ventricle (RV)) and at different time points.


RESULTS
There was no difference in sensing among the follow-up time points (p = 0.9). Thresholds at 3 months were significantly higher compared to the day of implant (p = 0.005) and the day after implant (p = 0.03). Impedances at implant were significantly higher compared to day 1 (p < 0.001), 3 months (p < 0.003), and 12 months (p < 0.001) post-implant. The mean percentage of RA pacing was 85 ± 6% the day after implant, 74 ± 6% at 3 months, and 80 ± 6% at 1 year (p = 0.17).


CONCLUSIONS
In cardiac transplant patients, pacing impedances decrease and thresholds trend up in short-term follow-up, but subsequent sensing, threshold, and impedance remain stable at 1 year. This is comparable to the pattern observed among noncardiac transplant PPM recipients. The atrial pacing percentage was stable over 1 year, suggesting continued relative sinus node dysfunction.
Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA. talha.farid@louisville.edu.|Department of Cardiovascular Medicine, University of Louisville, 201 Abraham Flexner Way, Louisville, KY, 40292, USA. talha.farid@louisville.edu.
Talha A
TA
Farid
Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.
Mohamed A
MA
Omer
St. Luke's Mid America Heart Institute, Kansas City, MO, USA.
Kensey
K
Gosch
Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.|St. Luke's Mid America Heart Institute, Kansas City, MO, USA.
Ashley
A
Moser
Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.|St. Luke's Mid America Heart Institute, Kansas City, MO, USA.
Bethany
B
Austin
Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.|St. Luke's Mid America Heart Institute, Kansas City, MO, USA.
Anthony
A
Magalski
Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.|St. Luke's Mid America Heart Institute, Kansas City, MO, USA.
Alan P
AP
Wimmer
D001146:Arrhythmia, Sinus / Q000175:diagnosis* / Q000209:etiology* / Q000517:prevention & control; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020380:Needs Assessment; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
Cardiac transplant; Pacing; Sinus node dysfunction