Electrocardiographic artifacts in clinical practice: A logical approach to recognition and prevention

Table 1 Signal pathway and artifact risks

Step	Function	Common artifact sources	Clinical example
Generation	The heart produces approximately 1 mV currents	Competing signals from the muscle	Myopotential artifacts mimicking atrial fibrillation
Detection	Electrodes capture surface signals	Sweat, hair, poor adhesion, movement	Wandering baseline or false ST elevation (baseline drift)
Transmission	Leads carry signals	Cable fracture, patient motion, EMI	Flatline due to broken lead; saw-tooth interference from cautery
Amplification and filtering	Boosts and cleans signals	Amplifies both signal and noise; filter distortion	QRS smoothed, or ST segments flattened, spurious ST shifts
Display and printing	Trace presented	All upstream noise is now visible	Artifact interpreted as ventricular tachycardia, acceleration or deceleration artifacts

EMI: Electromagnetic interference.