Carotid artery blood velocity decreases in patients with coronary slow flow: A manifestation of systemic arteriosclerosis.

OBJECTIVES

Coronary slow flow phenomenon (CSFP) could be a manifestation of systemic arteriosclerosis, as coronary and carotid arteries have similar intimal thickening. However, as an initial cause of arteriosclerosis, hemodynamic changes in carotid arteries have rarely been studied.

METHODS

Twenty patients with angiography-proven CSFP and 39 patients with normal coronary flow (NCF) were enrolled. TIMI frame counts (CTFC) were investigated. Carotid intima-media thickness (CIMT), peak systolic velocity (PSV), and end-diastolic velocity (EDV) were measured by ultrasonography, and shear rate (SR) and resistance index (RI) were calculated.

RESULTS

The results showed that PSV, EDV, SR, and RI were significantly lower in patients with CSFP (p＜0.01), but CIMT was significantly increased (P ＜ 0.01). PSV, EDV, SR, and RI were negatively correlated with CTFC, while CIMT was positively correlated with CTFC. Logistic regression analysis revealed that PSV (OR = 0.95, P < 0.01) could be an independent protective factor against CSFP, but CIMT (OR = 1.10, P ＜ 0.05) and male gender (OR = 9.89, P ＜ 0.01) could be risk factors for CSFP.

CONCLUSIONS

The slow flow phenomenon was observed in both coronary and carotid arteries, which could be a characteristic manifestation of systemic arteriosclerosis in CSFP; the lower wall shear stress may be the underlying mechanism. Carotid ultrasound could be applied in the noninvasive diagnosis of CSFP in the future.