Multifocal atrial arrhythmia--a frequent misdiagnosis? A correlative study using the computerized ECG.

All computerized ECGs taken over a 17-week study period were reviewed for the detection of multifocal atrial arrhythmia (MAA)--tachycardia or rhythm--and correlated with the diagnostic statement of the ECG computer system. MAA was identified by the authors in 96 of 11,610 (0.8%) computerized ECGs. In all instances, this specific arrhythmia was misclassified by the computer system as atrial fibrillation. Moreover, during the over-read, only 27.1% of ECGs were correctly diagnosed by the assigned electrocardiographers blinded to this study. MAA is not an uncommon atrial arrhythmia since it was identified in 14% of computerized ECGs interpreted as atrial fibrillation. This study supports the inference that MAA is indeed frequently misdiagnosed by most physicians and the need for improved ECG computer analysis programs for reliable detection of MAA.