Our aim was to perform a preliminary study of blood flow in the peripheral microcirculation in patients with heart failure. Cardiac patients were investigated to establish possible microcirculatory changes due to this pathology. We evaluated 16 patients (non-smokers, dislipidemic with hypercholesterolemia), receiving oral treatment and in NYHA class 2.3 +/- 0.5. A dilated cardiomyopathy (DCM) group was evaluated before cardiac resynchronization therapy (CRT) obtained by biventricular intra-cardiac defibrillator (ICD) implantation, and again 3 months after its implantation. We measured the ejection fraction (EF), peripheral blood flow (using laser Doppler) at the left wrist on the volar side, capillary morphology (using computerized videocapillaroscopy) on the nail bed of the 4th finger of the left hand, rheological status (using the LORCA), as well as hematocrit, hemoglobin concentration, red blood cell (RBC) surface acetylcholinesterase (AchE), and homocysteine. Our data show that in the DCM vs. control group, peripheral flow did not depend only on the heart: throughout the study, blood flow did not change significantly compared to controls and was increased after CRT. There was no decrease in aggregation time. The blood flow did not alter RBC deformability or RBC surface AchE. Due to the lower oxygenation and to a non-significant increase in the number of capillaries after CRT, DCM patients are at higher cardiovascular risk than healthy subjects.