Objective: Syncope is a common complaint and determining the underlying cause can be difficult despite extensive evaluation. The purpose of this study was to evaluate the usefulness of an implantable loop recorder for patients with unexplained syncope and palpitations.

Material and methods: This was a retrospective analysis of 18 patients, five of whom still have the device implanted. All patients had undergone extensive evaluation for their symptoms before getting the loop recorder implanted and this was therefore a highly select group. 

Results: Of the thirteen patients where use of the device was completed, the mean age was 65±20 years. The loop recorder was in use for a mean time of 20±13 months. Unexplained syncope, eleven of thirteen, was the most common indication. The other two received the  loop recorder for unexplained palpitations. Four patients had sick sinus syndrome during monitoring, three had supraventricular tachycardia and one had ventricular tachycardia. Further three had typical symptoms but no arrhythmia was recorded and  excluding that  as a cause. Two patients had no symptoms the entire time  they had the loop recorder. Of the five patients still with the device three  had syncope as the indication for monitoring and two have the device as a means  of  evaluating the results of treatment for arrhythmia.

Conclusion: This study on our initial experience with implantable loop recorders shows that these devices can be useful in the investigation of the causes of syncope and palpitations.

Kristjansdottir I, Reimarsdottir G, Arnar DO

Landspítali – The National University Hospital of Iceland.

Figure 1. An implantable loop recorder is the approximate size of an USB memory stick.

Figure 2. An electrocardiogram from an implantable loop recorder. The figure shows a long pause in a patient with recurrent syncope. He was subsequently treated with a pacemaker with good results.