Increasing averaging beats improves the test accuracy on Holter-based late potentials in patients with myocardial infarction

Abstract

Background: The prevalence of Holter-based late potentials (H-LPs) in cases of fatal cardiac events has increased. Although the noise level of H-LP is higher than that of conventional real-time late potential (LP) recording, a procedure to reduce the noise severity in H-LP by increasing the averaging beats has not been investigated.

Methods: We enrolled 104 patients with post-myocardial infarction (MI) and 86 control participants. Among the patients, 30 reported sustained ventricular tachycardia (VT), and the remaining 74 had unrecorded VT. H-LPs were measured twice in all groups to evaluate the efficacy of increasing the averaging beats for H-LPs. Thereafter, the average of LP was calculated at 250 (default setting), 300, 400, 500, 600, 700, and 800 beats.

Results: Across all three groups (MI-VT group, MI non-VT group, and control group), the noise levels significantly decreased in consonance with the increase in averaging beats. In the MI-VT group, the H-LP positive rate considerably increased with the increase in the averaging beats from 250 to 800 both at night and daytime. In the MI-VT group, the LP parameters significantly deteriorated, which led to a positive judgment corresponding to the increment of the averaged night and day beats. The H-LP positive rates were unchanged in the MI non-VT and control groups, while the LP parameters remained consistent, despite the increased averaging beats in the MI non-VT and control groups.

Conclusion: Increasing the calculated averaging beats in H-LPs can improve the sensitivity of predicting fatal cardiac events in patients with MI.

Keywords: increase averaging beats of late potential; late potentials; myocardial infarction; signal averaged electrocardiogram; sudden cardiac death; ventricular tachycardia.