The Real-World Utility of the LINQ Implantable Loop Recorder in Pediatric and Adult Congenital Heart Patients.

OBJECTIVES

This study sought to determine the practical use of the recently introduced LINQ implantable loop recorder (LINQ-ILR) in a cohort of pediatric and adult congenital arrhythmia patients.

BACKGROUND

Correlating symptoms to a causative arrhythmia is a key aspect of diagnosis and management in clinical electrophysiology.

METHODS

Retrospective review of clinical data, implantation indications, findings, and therapeutic decisions in patients who underwent LINQ-ILR implantation from April 1st, 2014 to January 30th, 2017 at Boston Children's Hospital.

RESULTS

A total of 133 patients were included, of which 76 (57%) were male. The mean age at implantation was 15.7 ± 9.1 years with a duration of follow-up of 11.8 months. Congenital heart disease was present in 34 patients (26%), a confirmed genetic diagnosis in 50 (38%), and cardiomyopathy in 22 (26%), and the remainder were without a previous diagnosis. Syncope was the most common indication for LINQ-ILR implantation, occurring in 59 patients (44%). The median time to diagnosis was 4.5 months, occurring in 78 patients (59%). Cardiac device placement occurred in 17 patients (22%), a medication change in 9 (12%), electrophysiology study/ablation in 5 (6%), or LINQ-ILR explantation in 42 (54%). Infection or erosion occurred in 5 patients. Syncope was correlated with a diagnostic transmission (54% vs. 31%, p = 0.01).

CONCLUSIONS

The LINQ-ILR is an important diagnostic tool, providing useful data in more than one-half of patients in <6 months. Adverse events are low. Patient selection is critical and undiagnosed syncope represents an important presenting indication for which a LINQ-ILR implant should be considered.