Title:Roles of MDA-LDL/OX-LDL/LOX-1 and TNF-α/TLR4/NF-κB Signaling
Pathways in Myocardial Damage by Implantations of Cardiac Pacemakers
in Elderly Patients
Volume: 22
Issue: 4
Author(s): Xia Li, Wenhang Zhou, Dianxuan Guo*, Youdong Hu, Hualan Zhou and Ying Chen
Affiliation:
- Xiamen Road Branch Hospital, The Affiliated Huaian Hospital of Xuzhou Medical University, Huaian 223002, China
Keywords:
Signalling pathways, myocardial damage, cardiac pacemakers, elderly, implantations, oxidative stress.
Abstract:
Introduction: Permanent pacemakers are an established treatment for sick sinus syndrome
and high-grade atrioventricular block. Permanent cardiac pacemaker implantations may damage the
myocardium.
Objective: This study evaluated markers of myocardial injury, oxidative stress and inflammation in
elderly patients with permanent pacemaker implantations.
Methods: Various markers were measured at 1, 2, 3 and 4 months after permanent pacemaker implantations
in elderly patients.
Results: The levels of high-sensitivity troponin T (hsTnT), lectin-like oxidized low-density lipoprotein
receptor-1 (LOX-1), malondialdehyde-modified low-density lipoprotein (MDA-LDL), oxidized
low-density lipoprotein (OX-LDL), tumour necrosis factor-α (TNF-α), toll-like receptor 4 (TLR4)
and nuclear factor-kappa B (NF-κB) were increased in 2-month group compared with control and 1-
month groups (P<0.001), and were further increased at 4-month group compared with 2- and 3-
month groups after pacemaker implantations (P<0.001). Patients with dual-chamber pacemakers had
higher levels of hsTnT, LOX-1, MDA-LDL, OX-LDL, TNF-α, TLR4 and NF-κB than patients with
single chamber pacemakers (P<0.001). Patients who underwent the pacemakers with the active fixation
leads had raised levels of hsTnT, LOX-1, MDA-LDL, OX-LDL, TNF-α, TLR4 and NF-κB
compared patients with pacemakers using the passive fixation leads (P<0.001). Myocardial blood
flows in 3-month and 4-month groups were lower than 1-month and 2-month groups (P<0.001).
Conclusion: Levels of hsTnT, LOX-1, MDA-LDL, OX-LDL, TNF-α, TLR4 and NF-κB were elevated
in elderly patients with permanent pacemaker implantations and the activations of oxidative
stress and pro-inflammatory signalling pathways may be associated with myocardial damages and
ischemia after pacemaker implantations in elderly patients.
