UCSF

Abstract

Determining the Ideal Electrode Configuration for Continuous In-Hospital Electrocardiographic (ECG) Monitoring

Richard L. Fidler, PhD(c), MSN, MBA, CRNA, ANP

Significance: Hospital ECG-monitoring is done using the Mason-Likar electrode configuration with chest-mounted and newer technology allows the addition of precordial electrodes to the bedside monitor to acquire a 12-lead ECG. Mason-Likar limb electrodes need to move to the limbs for a standard 12-lead ECG; however, if this step is missed nonstandard and nonequivalent ECG is obtained. The Lund electrode configuration, with more distal limb electrodes was proposed as a solution, but it is unknown how Lund and Mason-Likar compare in signal quality, false lethal arrhythmia alarms, and patient comfort.

Methods: One hundred patients from ICU and PCU were enrolled, and in addition to standard hospital monitoring equipment, each subject wore two Holter monitors, one in the Mason-Likar and the other in the Lund electrode configurations for a 24-hour period. Randomization to abrasive skin prep was conducted. ECG signals were sent for blinded analysis for signal quality using the Hook-Up Advisor® and arrhythmia analysis using EK-Pro®. Signal quality was rated as "green-yellow-red", and lethal arrhythmia alarms were categorized as true or false by clinicians. Qualitative patient data regarding the monitoring experience was also gathered.

Results: Subjects each provided a mean of 23.8-hours of data in both electrode configurations, and 45 subjects received abrasive skin preparation. Signal quality was compared between configurations using a paired t-test showing that the Mason-Likar configuration spent 8.2% more time in "green". There was no differences between electrode configurations in the numbers of false lethal arrhythmia alarms. Abrasive skin preparation did not confer a benefit in signal quality or false lethal arrhythmia alarms. Patients prefer options to carry monitoring equipment. Hairy patients prefer to be shaved to reduce pain at electrode removal.

Implications: There is a difference favoring the Mason-Likar configuration over Lund for mean ECG signal quality, and there is no difference in false lethal arrhythmia alarms. Mason-Likar should remain the choice for continuous in-hospital ECG monitoring. Skin preparation conferred no benefit in signal quality or false lethal arrhythmia detection.