Coronary subclavian steal: a recurrent case with notes on detecting the threat potential.

A 43-year-old military patient with silent myocardial ischemia due to proximal anterior descending coronary artery and major diagonal branch stenoses had left and right internal mammary artery grafts in 1973, with excellent angiographic results. In 1984, silent ischemia recurred, due to proximal subclavian occlusion with collateral subclavian steal from the left internal mammary artery. A carotid-subclavian artery graft required replacement in 1987 and in 1989 for steal recurrence from graft stenosis due to thrombosis/atherosclerosis. The final 12-mm graft remained smooth with conventional anticoagulant therapy. However, in 1994, ostial compromise of the left internal mammary artery reduced flow enough to require relief of the original and unchanged anterior descending stenosis by transluminal angioplasty and stent placement. Observations are made on subclavian steal and simple methods for detecting its potential for occurrence.