Coronary steal is defined as a fall in blood flow toward a certain vascular region in favor of another area during arteriolar vasodilatation, ie, a coronary flow velocity reserve (CFVR) <1.
Pathophysiology
Diagram depicting coronary collateral steal. At rest, microcirculation of myocardial region distal to stenotic conductance vessel maintains normal perfusion by compensatory predilatation. In situation illustrated, half of perfusion (50 mL/min [mL/′]) is provided by antegrade flow through stenotic vessel and half by collaterals (50 mL/min) from contralateral nonstenotic vessel. During hyperemia, capacity for further arteriolar dilatation in poststenotic region (left) is exhausted, whereas it is intact on contralateral collateral-supplying side. Thus, microvascular resistance is more reduced on collateral-providing side than on poststenotic side, thereby reducing flow via collaterals (to 25 mL/min in this example) and causing net myocardial perfusion during hyperemia to be less (ie, 85mL/min) than at resting conditions (ie, 100mL/min). | Christian, S., Martin, F., & Bernhard, M. (1997). Direct Intracoronary Evidence of Collateral Steal in Humans. Circulation, 96(12), 4261–4267. https://doi.org/10.1161/01.CIR.96.12.4261
Clinical features
Mimics myocardial infarction (MI):
Squeezing chest pain (radiates to left arm, jaw, shoulders, back)
Shortness of breath
Diaphoresis
Nausea
Fatigue
Clinical consequences of coronary subclavian steal syndrome. A high-grade proximal left subclavian artery stenosis results in reversal of blood flow up the left internal mammary artery away from the heart to maintain perfusion of the left upper extremity. Consequences of coronary subclavian steal syndrome are myocardial ischemia/infarction, heart failure, and malignant arrhythmias. CHF, congestive heart failure; MI, myocardial infarction; TIA, transient ischemic attack. | Takach, T.J., Reul, G.J., Cooley, D.A., Duncan, J.M., Livesay, J.J., Ott, D.A., and Gregoric, I.D. Myocardial thievery: the coronary-subclavian steal syndrome. Ann Thorac Surg. 2006; 81: 386–392
Diagnosis
Electrocardiogram (ECG):
ST-segment depression during stress test
Imaging:
Techniques:
USG duplex
CT angiography (CTA)
Magnetic resonance angiography (MRA)
Digital subtraction angiography (DSA)
Findings:
Coronary artery obstruction
Collateral vessel formation
Management
Balloon angioplasty
Percutaneous coronary intervention
Percutaneous treatment of coronary steal syndrome. (A), Coronary angiography revealed that LIMA had two separate unligated side branches (arrowheads); (B), The 4x10mm Amplatzer vascular plug 4 was released into the proximal side branch; (C), The 2 × 3 mm coil was released into the small caliber side branch; (D), The procedure was terminated showing complete flow cessations into the mentioned arteries (arrowheads). | Kahraman, S., Agac, M. T., Demirci, G., Gurbak, I., Panc, C., Yildiz, M., & Erturk, M. (2018). Successful percutaneous treatment of coronary steal syndrome with the amplatzer vascular plug 4 and coil embolization. Intractable & Rare Diseases Research, 7(4), 287–290. https://doi.org/10.5582/irdr.2018.01083
