Objective To investigate the effects of metoprolol succinate sustained-release tablets on acute phase ventricular pacing threshold and intracardiac electrical signal amplitude in a leadless pacemaker(Micra).Methods A total of 100 patients implanted with a leadless pacemaker were selected and divided into a study group(n=43)and a control group(n=57)according to whether oral metoprolol succinate sustained release tablets were postoperatively administered.The patients with underlying diseases including hypertension,coronary heart disease,or diabetes were treated with antihypertensive drugs,hypoglycemic drugs,or anti-platelet aggregation drugs.The study group received oral metoprolol succinate sustained release tablets within one to three days after implantation of a leadless pacemaker;while the control group received no metoprolol succinate sustained release tablets.Changes in ventricular pacing threshold and intracardiac electrical signal amplitude were observed in two groups one week,one month and three months after implantation.Results No serious complications occurred in the patients at the three time points after implantation.Ventricular pacing thresholds were stable in both groups,and there was no statistical significance between the two groups as compared with the same time period(P>0.05).In terms of amplitude of ventricular intracardiac electrical signal,theamplitude of ventricular R-wave did not differ significantly between the two groups at the three time points after implantation(P>0.05).Conclusions Oral administration of metoprolol succinate sustained release tablets had no significant effects on acute phase ventricular pacing threshold and intracardiac electrical signal amplitude in a leadless pacemaker(Micra).

Angiotensin-Converting Enzyme 2 ; COVID-19 ; Drug Repositioning ; Enzyme-Linked Immunosorbent Assay ; Humans ; Pharmaceutical Preparations ; SARS-CoV-2