What are ECG artifacts on EEG?

Updated: Oct 09, 2019
  • Author: Selim R Benbadis, MD; Chief Editor: Helmi L Lutsep, MD  more...
  • Print
Answer

Answer

Some individual variations in the amount and persistence of ECG artifact are related to the field of the heart potentials over the surface of the scalp. Generally, people with short and wide necks have the largest ECG artifacts on their EEGs. The voltage and apparent surface of the artifact vary from derivation to derivation and, consequently, from montage to montage. The artifact is observed best in referential montages using earlobe electrodes A1 and A2.

ECG artifact is recognized easily by its rhythmicity/regularity and coincidence with the ECG tracing (each "sharp wave" equals artifact that synchronizes with each QRS complex of the ECG channel; see image below). The situation becomes difficult when cerebral abnormal activity (eg, sharp waves) appears intermixed with EEG artifact, and the former may be overlooked. The EEG technologist should apply electrodes routinely to record the ECG.

Regular (periodic) slow waves best observed at mid Regular (periodic) slow waves best observed at midtemporal and posterior temporal electrodes T4-T6 and T3-T5. These clearly are related to ECG. The duration and morphology are those of pulse artifact, but as demonstrated by the marker, no delay occurs between the ECG and the artifact. Thus, this is an ECG artifact with broad QRS complexes.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!