Secondary Analysis to Advance Characterization of On-body Electrocardiographic Sensors in a Clinical Cocaine Self-administration Paradigm

Our group has previously established how remote on-body electrocardiogram (ECG) sensors may discriminate cocaine use from other sympathomimetic conditions. The current analyses assess whether discriminatory power is mainly driven by differences in heart rate between conditions.

Individuals who use cocaine (N = 11) wore ECG sensors during (1) cocaine self-administration, (2) methylphenidate administration, (3) aerobic exercise, and (4) tobacco use (N = 9). Primary outcomes included: (1) time elapsed between 2 successive R waves (ie, RR interval), (2) ECG interval proxies, and (3) waveforms. ECG traces were matched for heart rate between conditions for all discriminations.

ECG interval proxies and waveforms exhibited high discriminatory power in distinguishing cocaine use from methylphenidate, exercise, and tobacco use, with mean areas under the receiver operating characteristics ranging from 0.87 to 0.99, while RR-related measures ranged from 0.49 to 0.5, reflecting low discriminatory power.

Our results suggest that the ECG sensors' discriminatory power is based on nuances in ECG data beyond mere changes in heart rate.