Implantable loop recorder monitoring in patients with cryptogenic stroke - Detection and treatment of different clinically relevant arrhythmias

AIMS: Implantable loop recorders (ILR) are recommended to detect atrial fibrillation (AF) in cases of cryptogenic stroke. However, real life data besides controlled trials are rare. Aim of the study was the detection of atrial fibrillation with a special focus on other arrhythmias according to criteria defined in earlier clinical trials.

METHODS: We performed a retrospective analysis of 64 patients with cryptogenic stroke who underwent ILR implantation between 4/2014 and 1/2018. The primary endpoint was the detection of atrial fibrillation, significant bradycardia (<40 bpm) or tachycardia (>150 bpm). ILR interrogation was performed after implantation and 6, 12 and 24 months thereafter.

RESULTS: Mean patients age was 65.4 ± 12 years, 50% were male. Mean follow-up duration was 419.2 ± 309 days. One death occurred during follow-up. 23 patients (35.9%) experienced a symptomatic clinical neurological or cardiac event during follow-up. Overall rate of detected arrhythmias was 35% (23/64). The most frequent arrhythmia was atrial fibrillation which was observed in 16 patients (25%). 6 of 16 patients presenting with atrial fibrillation had no clinical symptoms. Bradycardias requiring subsequent pacemaker implantations were detected in 9.4%. A ventricular tachycardia was observed in one patient (1.6%).

CONCLUSION: In this group of patients with cryptogenic stroke the rate of arrhythmic events was high. Besides a high rate of atrial fibrillation (25%), an unexpectedly high rate of bradyarrhythmias (9.4%) occurred in our patient collective. Since many of those episodes were clinically asymptomatic, the ILR helps to detect and treat those clinically silent arrhythmias.