Well-being and cerebral oxygen saturation during acute heart failure in humans

Cerebral symptoms and near-infrared spectrophotometry-determined cerebral o xygen saturation (ScO2) were followed in patients treated for normotensive acute congestive heart failure. The reproducibility and normal range for Sc O2 were established from 39 resting subjects without cardio-respiratory dis ease: the ScO2 ranged from 55 to 78% with a coefficient of variation for tr iple determination of 6%. Patients rated cerebral symptoms on a scale with end-points of 0 (best) and 10 (worst). In eight patients with acute heart f ailure, arterial oxygen tension increased during decongestive treatment, fr om 9.1 (4.9-10) to 10.4 kPa (7.3-17); median with range, as did arterial ox ygen saturation, from 94 (48-97) to 97% (87-99) (P < 0.02), whereas the mea n arterial pressure, heart rate and arterial carbon dioxide tension remaine d unchanged. The cerebral symptom score improved from 8 (3-10) to 1 (1-9) a nd the ScO2 increased from 34 (20-58) to 50% (19-91) (P < 0.02). A ninth pa tient presented with a silent but massive myocardial infarction: she was ce rebrally obtunded with a ScO2 of 18% and soon died. In patients with normot ensive acute heart failure and cerebral symptoms, cerebral oxygen saturatio n is low, and during successful treatment ScO2 increases with the well-bein g of the patient.