Multimodality imaging of coronary-subclavian-vertebral steal syndrome.

A 59-year-old man was admitted with unresolved chest pain after coronary artery bypass graft surgery that had been performed 3 years earlier; aorta-obtuse marginalis, and aorta-posterior descending artery with the use of a saphenous vein graft and left anterior descending arteryleft internal mammary artery (LIMA). He reported recurrent angina pectoris and cerebral symptoms, including dizziness and drop attacks, especially when moving his left arm. When he stopped moving his left upper extremity, these symptoms were spontaneously resolved within minutes. On physical examination, pulse rate was regular at 72 beats/min, and there was a significant blood pressure difference between the right and the left arm (135/ 85 mm Hg and 95/65 mm Hg, respectively). On auscultation, there was a marked bruit at the left supraclavicular region. The results of transthoracic echocardiography were within normal limits. We performed coronary computed tomography angiography to display the cause of ischemic symptoms. Coronary computed tomography angiography revealed that the left subclavian artery was totally occluded 2 cm from its origin (Figure 1A), but all grafts and the left vertebral artery were patent (Figure 1B). It was also shown that the distal part of the occluded left subclavian artery was filling with contrast media, which made us think about retrograde flow from the left vertebral artery and/or the LIMA. Therefore, cardiac MRI was also performed to evaluate flow directions at the LIMA and left vertebral artery. Phase-contrast velocity mapping of the right internal mammary artery and the LIMA graft in the transaxial plane (Figure 2A) showed antegrade caudally directed flow in the right internal mammary artery, but predominantly retrograde flow in the cranial direction in the LIMA (Figure 2B). With the use of the same technique, it was also showed the right and left vertebral arteries in the transaxial plane (Figure 3A) and antegrade cranially