Coronary Steal: Mechanisms of a Misnomer

1. In keeping with its original description, a literature review for "coronary steal" demonstrates that a large minority (213 of the 514 results [41%]) involves congenital heart disease, within the limitations of a PubMed search. (PubMed search performed on February 8, 2021, using terms ("coronary steal"[tiab] OR "myocardial steal"[tiab]) in general, ("fistula"[tiab] OR "fistulae"[tiab] OR "fistulas"[tiab] OR "congenital"[tiab] OR "anomalous"[tiab] OR "hypoplastic"[tiab] OR "arterial switch"[tiab] OR "BlandWhiteGarland"[tiab] OR "arteriovenous malformation"[tiab] OR "fetal hydrops"[tiab] OR "tetralogy"[tiab]) for congenital heart disease, ("mammary"[tiab] OR "thoracic artery" OR "bypass"[tiab] OR "subclavian steal"[tiab] OR "IMA graft"[tiab] OR "thoracic branch"[tiab]) for bypassrelated steal, ("myxoma"[tiab] OR "mediastinal mass"[tiab] OR "cardiac hemangioma"[tiab] OR "tumor"[tiab]) for tumors, "isoflurane"[tiab] for isoflurane). 2. Coronary steal has been described after bypass grafting of an internal mammary artery distal to a subclavian stenosis3 or attributed to unligated side branches of the mammary artery, although the latter mechanism remains controversial because coronary flow occurs during diastole whereas side branches perfuse during systole.4 This group accounts for 86 of the 514 results (17%). 3. Symptoms associated with cardiac tumors have been attributed to coronary steal in a small number of cases series, albeit without supporting hemodynamics, making up 9 of the 514 results (2%). 4. Inhaled anesthetic isoflurane underwent intense investigation because of an initial concern for its potential to cause coronary steal that was ultimately disproven.5 This topic consumes 22 of the 514 results (4%). 5. The remaining 184 of 514 results (36%) from PubMed largely focus on severe coronary artery disease as detailed subsequently.