Electrocardiogram signal (ECG)

An Electrocardiogram (ECG) signal is a non-invasive diagnostic recording of the heart's electrical activity over time, captured using electrodes placed on the skin (StatPearls, 2023). It represents the spatial summation of action potentials from myocardial cells, specifically reflecting the depolarization and repolarization phases of the cardiac cycle (NIH, 2022). Although the ECG signal is not a therapeutic target like a protein or receptor, it is a primary pharmacodynamic biomarker used to evaluate cardiac safety and drug efficacy (FDA, 2005). Drugs that influence cardiac ion channels, such as anti-arrhythmics or those with off-target hERG inhibition, can cause measurable changes in the ECG trace, which are critical for predicting pro-arrhythmic risks like Torsades de Pointes (PubMed, 2021). Consequently, the ECG remains the gold standard for monitoring the physiological impact of various therapeutic agents on the cardiovascular system.

Other names

EKGElectrocardiographyCardiac electrical activityHeart rhythm recording

Drugs do not bind to the ECG signal itself; rather, they modulate the signal by interacting with underlying molecular targets such as voltage-gated ion channels (e.g., KCNH2/hERG, SCN5A) or the autonomic nervous system, which alters the speed and pattern of cardiac electrical impulses (StatPearls, 2023; NIH, 2022).