Abstract:
Objective
To bolster the evidence for the early clinical application of implantable cardiac monitors （ICM） in high-risk patients and to optimize effective pacemaker therapy， by retrospectively analyzing the predictors for the need for pacemaker therapy in patients with unexplained syncope who underwent implantation of an ICM.
Methods
A total of 127 patients hospitalized for unexplained syncope and received ICM implantation at Beijing Friendship Hospital， Capital Medical University， between December 2019 and June 2022， were consecutively enrolled. Among them， 52 patients diagnosed with bradyarrhythmias through ICM monitoring met the criteria for permanent pacemaker （PPM） implantation（PPM indication group）， while 75 patients did not exhibit bradyarrhythmias （non-PPM indication group）.Both groups were followed up until June 2024. During the follow-up， syncope/presyncope-related events were recorded， and etiological analysis and corresponding treatments were conducted. Predictors for the need for PPM implantation due to bradyarrhythmias detected by ICM were also evaluated.
Results
Patients in the PPM indication group were older （P=0.030） and had a slower minimum heart rate （P＜0.001）， with a higher incidence of pauses exceeding 2 seconds （P＜0.001）. First-degree atrioventricular block （AVB）， firstdegree AVB combined with right bundle branch block （RBBB）， or left bundle branch block （LBBB） were more common in this group （P＜0.001， P=0.039， and P=0.016， respectively）. Multivariate analysis identified the minimum heart rate （P=0.024）， PR interval （P＜0.001）， and pauses ＞2 seconds （P＜0.001） detected by HOLTER monitoring as independent predictors of the need for PPM implantation due to bradyarrhythmias diagnosed by ICM. Moreover， the area under curve （AUC） of the receiver operating characteristic curve for the combined predictive value of these three factors was higher （AUC=0.840， 95% CI: 0.770-0.909）.
Conclusion
The minimum heart rate， PR interval， and pauses ＞2 seconds detected by HOLTER monitoring are significant risk factors for predicting the need for PPM implantation guided by ICM. Early ICM implantation may be particularly beneficial for high-risk patients with unexplained syncope.
Key words:
Unexplained syncope,
Insertable cardiac monitor,
Permanent pacemaker,
Predictors
Zhijun1 Sun, Lifeng Liang, Xiaona Liu, Wangyang Yang, Beibing Di, Nixiao1 Zhang, Hui Peng. Identifying predictive factors for pacemaker implantation in patients with unexplained syncope receiving implantable cardiac monitor[J]. Chinese Journal of Cerebrovascular Diseases(Electronic Edition), 2024, 18(05): 446-453.