Coronary Steal Syndrome

Coronary Steal Syndrome is a heart condition that affects the blood flow in the arteries supplying the heart muscle. It occurs when blood is redirected away from an area of the heart that already has reduced blood supply, causing that area to receive even less oxygen. This happens because of abnormal blood vessel behavior, often related to blockages or narrowed arteries. The main body system involved is the cardiovascular system, specifically the coronary arteries. The syndrome can lead to chest pain, shortness of breath, and other symptoms of heart ischemia. It is important because it can worsen heart function and increase the risk of heart attacks. Understanding this condition helps explain why some treatments may cause symptoms to worsen temporarily.

Coronary Steal Syndrome is a pathophysiological condition characterized by the diversion of blood flow from a stenotic or ischemic region of the myocardium to an area supplied by a non-stenotic artery, typically due to pharmacologic or physiologic vasodilation of collateral vessels. The core pathology involves impaired coronary autoregulation where vasodilation in healthy vessels reduces perfusion pressure distal to a fixed coronary stenosis, leading to decreased blood flow in the affected myocardial territory. It is most commonly caused by administration of vasodilators such as dipyridamole or adenosine during stress testing or in patients with coronary artery disease. The major clinical significance lies in its potential to induce or exacerbate myocardial ischemia, manifesting as angina or ischemic ECG changes. This syndrome highlights the complex interplay between coronary anatomy, collateral circulation, and pharmacologic agents. Recognition of this phenomenon is critical in interpreting stress test results and managing patients with multivessel coronary artery disease.