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PR Interval and the Risks of Recurrent Syncope and All-Cause Mortality in Patients Presenting With Syncope
Asger Knudsen1, Johannes Jan Struijk1, Sam Riahi2,3
1Department of Health Science and Technology Aalborg University Aalborg Denmark.
Journal of the American Heart Association
|February 11, 2026
Summary
A short PR interval in syncope patients increases all-cause mortality risk. A long PR interval is linked to a higher rate of recurrent syncope. This study highlights PR interval significance in syncope risk assessment.
Area of Science:
- Cardiology
- Clinical Electrophysiology
- Public Health
Background:
- Syncope risk assessment often overlooks PR interval duration.
- Short PR interval is linked to atrial fibrillation and mortality.
- Understanding PR interval's role in syncope outcomes is crucial.
Purpose of the Study:
- To investigate the association between PR interval duration and all-cause mortality in syncope patients.
- To explore the relationship between PR interval duration and recurrent syncope.
Main Methods:
- Analysis of ECGs from 52,038 syncope patients within 24 hours of admission.
- Patients categorized into short (<120 ms), normal (120-200 ms), or long (>200 ms) PR interval groups.
- Exclusion of patients with ECG abnormalities or comorbidities affecting PR interval or outcomes.
Main Results:
- Short PR interval associated with a 1.50 hazard ratio for all-cause mortality (P<0.001).
- Long PR interval showed no association with all-cause mortality (HR 1.02, P=0.3566).
- Long PR interval linked to a 1.14 hazard ratio for recurrent syncope (P<0.001).
Conclusions:
- Short PR interval is a significant predictor of increased all-cause mortality in syncope patients.
- Long PR interval is associated with a higher incidence of recurrent syncope.
- PR interval duration should be considered in syncope risk stratification.
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