Bradyarrhythmias in patients with embolic stroke of undetermined source: a tight relationship with atrial cardiomyopathy.

Background: Implantable loop recorders (ILRs) have been shown to significantly improve the detection of atrial fibrillation (AF) in patients with embolic stroke of undetermined source (ESUS). The incidence and characterization of bradyarrhythmias in this subset of patients is still unknown.

Methods: All consecutive patients who received ILRs, after an ESUS, between March 2015 and December 2022 in our Center were retrospectively enrolled and analyzed. Bradyarrhythmias were defined as: (1) sinus node dysfunction defined as sinus bradycardia, pause or arrest, exit block; (2) second-degree heart block or complete atrioventricular block. The primary endpoint was to analyze the incidence and characterization of bradyarrhythmias; the secondary endpoint was the detection of possible risk factors for bradyarrythmias. All patients were followed through the remote monitoring.

Results: A total of 150 consecutive patients (mean age 70.4 ± 10.3 years old, 52.7% males) were analyzed. Bradyarrythmias were identified in 13 patients (8.7%). On multivariable analysis the presence of AF and first degree AV block were independently associated with the occurrence of bradyarrhythmias (respectively, OR 4.95, 95% CI 1.12-21.89, p = 0.0.03 and OR 3.77, 95% CI 1.08-13.14, p = 0.04).

Conclusions: The incidence of bradyarrhythmias detected by ILRs in patients with ESUS was 8.7%. Atrial fibrillation, left atrial enlargement and first degree AV block due to prolonged P wave duration were associated with the occurrence of bradyarrhythmias during the follow up.