Background: Dermal and myocardial injury results in a healing process, characterized by inflammation and fibrosis. We aimed to investigate association between proliferative scarring at the operation site and right ventricular (RV) pacing and sensing parameters, two clinical outcomes associated with impaired dermal and myocardial healing, respectively.
Methods: We performed an observational retrospective study among regularly followed pacemaker (PM)/implantable cardioverter defibrillator (ICD)-implanted patients at our medical center. Patients, who had a first RV active fixation PM/ICD lead implantation procedure and a minimum follow-up of 1 year, were included in the study. Redo procedures, passive fixation RV leads, epicardial leads, generator replacement procedures, and patients using class I and III anti-arrhythmic drugs were excluded. Patients in the control group, matched by age, sex and implanted device and lead type, were randomly selected from the patient pool. Lead impedance, pacing threshold, and R wave measurements obtained at baseline and at 3rd, 6th, and 12th month were analyzed.
Results: Baseline characteristics of study and control groups were similar. While baseline and follow-up lead impedance and R wave measurements along with baseline and 3rd-month pacing thresholds showed no significant difference between two groups, 6th- and 12th-month pacing thresholds revealed statistically significant increase in proliferative scar group compared to control group (0.87 vs 0.72 p = 0.003 and 0.87 vs 0.71 p = 0.003, respectively).
Conclusions: PM/ICD-implanted patients with proliferative scar on pocket wound may show increased RV pacing thresholds compared to patients with normal healing of pocket wound.
Keywords: Active fixation lead; Implantable cardioverter defibrillator; Pacemaker; Pacing threshold; Proliferative scar.