title: Early haemodynamic changes in cerebral blood flow after cardiac resychronisation therapy.
abstract: OBJECTIVE
  Cardiac resynchronisation therapy (CRT) has emerged as a new treatment strategy for a subgroup of patients with heart failure. In this study, we aimed to evaluate acute effects of CRT on cerebral blood flow.
  
  
  METHODS
  Twenty-two (six female and 16 male) patients (mean age 60.8±5.3 years) with idiopathic dilated cardiomyopathy were enrolled in the study. Blood flow in the common carotid artery (CCA), internal carotid artery (ICA), and vertebral arteries (VA) was evaluated by Colour Doppler ultrasound. All measurements were performed at a constant heart rate of 90beats/min for excluding the influence of variant heart rates.
  
  
  RESULTS
  Flow velocities, flow volume, resistivity and pulsatility indices which were correlated with cardiac output (CO) significantly increased after CRT. The only parameter affecting the change in mean velocity and flow volume in VA was the change in the CO (β=1.1, p=0.02 and β=1.2, p=0.04, respectively). The change in peak systolic velocity after CRT in VA and the change in mean velocity and volume in ICA were affected by the change in the CO (β=1.2, p=0.007; β=0.8, p=0.08 and β=0.6, p=0.03, respectively). The change in total cerebral blood flow was also affected by the change in CO (β=1.3, p=0.003).
  
  
  CONCLUSIONS
  CRT increases the carotid and vertebral artery blood flow velocities, flow volumes and therefore improves cerebral blood flow. This improvement in the cerebral blood flow after CRT is largely due to the increase in the cardiac output.
authors.affiliation: Koru Hospital, Cardiology Clinics, Ankara, Turkey. drozdemir75@yahoo.com
authors.forename: Ozcan
authors.initials: O
authors.lastname: Ozdemir
authors.forename: Mustafa
authors.initials: M
authors.lastname: Soylu
authors.forename: Tahir
authors.initials: T
authors.lastname: Durmaz
authors.forename: Ozgur
authors.initials: O
authors.lastname: Tosun
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D058406:Cardiac Resynchronization Therapy; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000503:physiopathology; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018615:Ultrasonography, Doppler, Color