Common electrocardiographic artifacts mimicking arrhythmias in ambulatory monitoring.
BACKGROUND
Ambulatory electrocardiographic monitoring is used in clinical practice as a means of detecting cardiac arrhythmias during daily activities. Current equipment provides analysis for the detection of arrhythmias, ST-segment deviation, and more sophisticated analyses (late potentials, Q-T behavior, and heart-rate variability). However, despite the system used, a number of artifacts could mislead diagnosis.


RESULTS
We prospectively searched for artifacts during ambulatory electrocardiography in patients referred for monitoring to our institution, a tertiary referral center. Patients were ambulatory at home, work, school, or within the hospital. We divided artifacts according to Krasnow and Bloomfield's classification (pseudoarrhythmia, nonarrhythmia), and we added a new category, artifacts in patients with pacemakers. Artifacts encountered mimicked sinus arrest, supraventricular arrhythmias, ventricular arrhythmias, and aberrancy. Examples of each one and diagnostic clues are provided to recognize these artifacts properly.


CONCLUSIONS
A substantial amount of invalid data (false-positive findings because of electrocardiographic artifacts) were identified during ambulatory electrocardiographic monitoring that can lead to inappropriate interpretation and may result in severe diagnostic errors.
Márquez
Manlio F
MF
Department of Electrocardiography and Cardiac Electrophysiology, Instituto Nacional de Cardiología Ignacio Chávez, México DF, México. manliomarquez@yahoo.com
Colín
Luis
L
Guevara
Milton
M
Iturralde
Pedro
P
Hermosillo
Antonio G
AG
D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D016477:Artifacts; D003951:Diagnostic Errors; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D004868:Equipment Failure; D006801:Humans; D018670:Monitoring, Ambulatory; D010138:Pacemaker, Artificial; D012815:Signal Processing, Computer-Assisted