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

Figure 7 Equipment-related and environmental artifacts. A: Missing PQRSs due to processing failure with residual T waves give rise to double T waves or “orphan T” waves (arrows); B: Arterial pulse tapping artifact mimicking ST elevation. All QRS complexes are followed by artifacts with electromechanical associations. Note that lead 2 is spared, meaning that the artifact comes from the left arm electrode; C: Similarly, arterial pulse tapping artifacts mimic bizarre T waves with prolonged QT intervals. Note that lead 1 is spared, meaning that the artifact comes from the left lower limb electrode; D: Electrocardiogram showing fixed-frequency square wave artifacts. ECG: Electrocardiogram.