1014-92 Impaired Microcirculation in Chronic Heart Failure

The microcirculation plays a crucial role in the exchange of oxygen, energy rich substrates and metabolites. The effects on the microcirculation of impaired heart function and disturbed peripheral skin circulation in chronic heart failure (CHF) are unknown. Nailfold capillary morphology and dynamics in CHF were studied in relation to parameters of left ventricular (LV) structure and function. Twenty patients (13 male, 7 female, age 64±2 years) with CHF NYHA class II underwent a capillaroscopic examination at the finger nailfold using a computerised videophotometric system (Capiflow) at rest and after 1 min arterial occlusion. Patients were treated with diuretics, ACE inhibitors and digoxin and mean duration of symptoms was 65±9 months. Study parameters were number, length, and diameter of the capillaries as well as capillary blood velocity (CBV). Further experiments included echocardiography and determination of LV ejection fraction by Tc-scintigraphy. Nailfold capillaries in established CHF are enlarged (afferent diameter 6.6±0.4 μm, efferent diameter 8.2±0.4 μm, ref. resp. <6 and <8 μm) and CBV is dramatically decreased (351±64 μ/s, ref. >600 μm/s at 23°C). The reactive hyperemic response to one minute arterial occlusion is attenuated (peak CBV 879±158 μm/s, ref >2000 μm/s). CBV correlates positively with LV ejection fraction (r=0.61, p=001) and inversely with LV end-diastolic (r=-0.56, P=0.04) and end-systolic (r=-0.69, P=0.01) diameters. The time-to-peak flow (35±5 s, ref. 6–10 s) after one min arterial occlusion is positively related (r=0.68, P<0.05) to the duration of CHF. Our data indicate that microcirculation in chronic heart failure deteriorates in function of the severity and duration of heart failure