title: Cerebral blood flow autoregulation in ischemic heart failure.
abstract: Patients with ischemic heart failure (iHF) have a high risk of neurological complications such as cognitive impairment and stroke. We hypothesized that iHF patients have a higher incidence of impaired dynamic cerebral autoregulation (dCA). Adult patients with iHF and healthy volunteers were included. Cerebral blood flow velocity (CBFV, transcranial Doppler, middle cerebral artery), end-tidal CO2(capnography), and arterial blood pressure (Finometer) were continuously recorded supine for 5 min at rest. Autoregulation index (ARI) was estimated from the CBFV step response derived by transfer function analysis using standard template curves. Fifty-two iHF patients and 54 age-, gender-, and BP-matched healthy volunteers were studied. Echocardiogram ejection fraction was 40 (20-45) % in iHF group. iHF patients compared with control subjects had reduced end-tidal CO2(34.1 ± 3.7 vs. 38.3 ± 4.0 mmHg, P < 0.001) and lower ARI values (5.1 ± 1.6 vs. 5.9 ± 1.0, P = 0.012). ARI <4, suggestive of impaired CA, was more common in iHF patients (28.8 vs. 7.4%, P = 0.004). These results confirm that iHF patients are more likely to have impaired dCA compared with age-matched controls. The relationship between impaired dCA and neurological complications in iHF patients deserves further investigation.
authors.affiliation: Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil.|Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.
authors.forename: J R
authors.initials: JR
authors.lastname: Caldas
authors.affiliation: Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom; rp9@le.ac.uk.|Leicester National Institute for Health Research Biomedical Research Unit in Cardiovascular Disease, Glenfield Hospital, Leicester, United Kingdom.
authors.forename: R B
authors.initials: RB
authors.lastname: Panerai
authors.affiliation: Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.|Leicester National Institute for Health Research Biomedical Research Unit in Cardiovascular Disease, Glenfield Hospital, Leicester, United Kingdom.
authors.forename: V J
authors.initials: VJ
authors.lastname: Haunton
authors.affiliation: Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: J P
authors.initials: JP
authors.lastname: Almeida
authors.affiliation: Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: G S R
authors.initials: GS
authors.lastname: Ferreira
authors.affiliation: Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Camara
authors.affiliation: Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.|Department of Neurology, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil; and.
authors.forename: R C
authors.initials: RC
authors.lastname: Nogueira
authors.affiliation: Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Bor-Seng-Shu
authors.affiliation: Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.
authors.forename: M L
authors.initials: ML
authors.lastname: Oliveira
authors.affiliation: Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: R R V
authors.initials: RR
authors.lastname: Groehs
authors.affiliation: Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Ferreira-Santos
authors.affiliation: Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.
authors.forename: M J
authors.initials: MJ
authors.lastname: Teixeira
authors.affiliation: Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: F R B G
authors.initials: FR
authors.lastname: Galas
authors.affiliation: Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.|Leicester National Institute for Health Research Biomedical Research Unit in Cardiovascular Disease, Glenfield Hospital, Leicester, United Kingdom.
authors.forename: T G
authors.initials: TG
authors.lastname: Robinson
authors.affiliation: Department of Cardiopneumology, Heart Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: F B
authors.initials: FB
authors.lastname: Jatene
authors.affiliation: Department of Cardiopneumology, Heart Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: L A
authors.initials: LA
authors.lastname: Hajjar
mesh_terms: D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000503:physiopathology*; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000503:physiopathology*
keywords: autoregulation index; cerebral blood flow; dynamic cerebral autoregulation; transcranial Doppler; transfer function analysis