Microcirculation and blood rheology abnormalities in chronic heart failure

BACKGROUND: Generalized restricted blood flow is hallmark of CHF of any etiology, but the extent of microcirculation restriction and the role of intrinsic blood properties in heart failure remains unknown. OBJECTIVE: The aim of this study was to estimate the microvascular blood flow and hemorheological properties in chronic heart failure to test the hypothesis that CHF patients have altered peripheral blood flow which contributes to the tissue perfusion disturbances. METHODS: Cutaneous microvascular blood flow was estimated by Laser Doppler and Optical Tissue Oximetry techniques. Whole blood and plasma viscosity were measured by capillary viscometer, red blood cell aggregation was evaluated by direct microscopic method, erythrocyte deformability was assessed as elongation index in flow microchamber. Hematocrit-to-viscosity ratio was used as index of oxygen transport efficacy. RESULTS: Depression of the regulatory mechanisms of microvascular blood flow as well as decreased tissue perfusion indicated the restricted blood flow in microcirculatory network in CHF. Increased blood and plasma viscosity, enhanced red blood cell aggregation and decreased erythrocyte deformability were registered in CHF. CONCLUSIONS: Complex impairment of peripheral blood flow in CHF including restricted microcirculation, attenuated regulatory mechanisms and impaired hemorheological properties caused the reduced oxygen utilization contributing to symptoms and advance of heart failure.