Noninvasive long-term ECG monitoring vs. loop recorder implantation for the atrial fibrillation management

Subcutaneouscardiac Rhythm Monitors: A Comprehensive Review

Subcutaneous loop recorders (SCRMs) are subcutaneous electronic devices which have revolutionized the field of arrhythmia detection. They have become increasingly appealing due to advances such as miniaturization of device, longer battery life, bluetooth capabilities and relatively simple implantation technique without the need for complex surgical suites. They can be implanted in the office, patient bedside without the need to go to the operating room. One of the most common indications for their implantation is detection of atrial fibrillation (AF) after a cryptogenic stroke. They have also been utilized for assessing the success of rhythm control strategies such post pulmonary venous isolation. More recently studies have assessed the utility of SCRMs for detecting silent AF in at risk populations such as patients with sleep apnea or those on hemodialysis. In this paper, we review the evolution of SCRMs, the clinical studies assessing their value for different indications, their role incurrent clinical practice and future avenues in the era of smart wearable devices like apple watch etc.

Noninvasive long-term ECG monitoring vs. loop recorder implantation for the atrial fibrillation management

OBJECTIVE

The objective of the study was to estimate the efficacy of a noninvasive ambulatory ECG monitoring (NIAM) in comparison with implantable loop recorder (ILR) in patients with atrial fibrillation (AF).

METHODS

Thirty-two patients 58 [47; 73] years of age with AF were included in the study. Patients were randomized into two groups: in group I (n = 15), "Reveal XT" ILR was used for invasive ECG monitoring up to 3 months; in group II (n = 17), "Spyder" device was used for NIAM up to 14 days.

RESULTS

In both groups, at least one AF episode was detected during 14 days of monitoring. The overall count of AF episodes was 25 in NIAM group and 28 in ILR group. The mean time between AF start and its registration by a physician was 8 hr in NIAM group and 20 hr in ILR group (p = .005). The diagnostic value parameters of NIAM were as follows: sensitivity-80.1%, specificity-73.1%; positive predictive value-74.1%; and negative predictive value-79.2%. The same parameters in ILR group were comparable with NIAM: sensitivity-78.6%; specificity-69%; positive predictive value-71%; and negative predictive value-77%. At the same time, continued monitoring with ILR for longer than two weeks did not lead to a significant change in the sensitivity and specificity of the method.

CONCLUSION

In patients with paroxysmal AF, the diagnostic value of both NIAM and ILR is comparable. An increase in the duration of ECG monitoring for longer than two weeks does not provide additional diagnostic information.