The South African flag sign (SAFS) is an acute, dynamic electrocardiographic (ECG) finding typically associated with first diagonal (D1) artery occlusion. We report the case of a 47-year-old woman who exhibited this pattern but subsequently revealed the dreaded "widow-maker" lesion (100% occluded proximal left anterior descending [LAD] artery) and severe multivessel disease (90% stenosis of the posterior left ventricular [PLV] artery and 80% stenosis of the left circumflex artery [LCx]).
Keywords: ST-segment acute coronary syndrome (STE-ACS); South African flag sign (SAFS); myocardial infarction (MI); proximal left anterior descending (LAD) stenosis; “widow-maker,” multivessel coronary artery disease (MVD).