HEMODYNAMIC MECHANISM OF “BLOOD STOLEN” PHENOMENON IN CORONARY ARTERY ANEURYSM

Blood is lost in coronary artery aneurysm (CAA), leading to a decrease in downstream blood flow, called the "blood stolen" phenomenon. In the clinic, the "blood stolen" phenomenon may lead to dilated myocardial ischemia. The mechanism of dilated myocardial ischemia, which is different from that of stenotic myocardial ischemia, has not yet been studied. The purpose of this study is to reveal the mechanism of dilated myocardial ischemia induced by the "blood stolen" phenomenon. In this paper, a lumped parameter model of the cardiovascular system with a CAA was established, a parallel structure was used to represent CAA. Three different sized CAAs were simulated, and their upstream and downstream blood flows were observed. The results showed that small and medium CAAs lead to 5.21% and 9.57% reductions, respectively, in the downstream flow. Giant CAAs lead to a more than 14% reduction in the downstream flow, while the upstream blood flow showed diastolic backward flow. The results of this numerical simulation are consistent with the clinical description. When blood flows into CAAs, it cannot flow downstream normally, and due to the wall elasticity of the CAA, there is diastolic backward flow, eventually leading to dilated myocardial ischemia. With expansion of the CAA, the "blood stolen" phenomenon will be more severe.