A 4-week-old female infant presented with congestive heart failure, mo
derate mitral regurgitation, and an electrocardiographic pattern of an
terolateral myocardial infarction. Angiography revealed normal coronar
y arteries and moderate mitral regurgitation. A single-catheter electr
ophysiology study confirmed the presence of an accessory atrioventricu
lar conduction pathway.