[Is brain blood supply affected by changes in cardiac volume? Measurements of brain blood supply in healthy subjects during volume overload and in patients with artificial pacemaker by changing the pacing rate].
A constant cerebral blood flow (CBF) in the presence of systemic blood pressure changes and cardiac output (CO) alterations during physiological conditions are postulated by the mechanism of cerebral autoregulation. The aim of the present study is the analysis of CBF in pacemaker (PM) patients with unspecific neurological symptoms. CBF was measured in 9 controls and 23 pacemaker patients with 133xenon, CO using Doppler echocardiography or impedance cardiography. Mean and individual CBF in controls remained unchanged when a CO increase of 28% induced by volume overload was observed. In PM patients a mean CO increase of 38% induced by an increase of basic pacing rate caused different effects of CBF. CBF increased or decreased by about 10% or remained constant. In summary, the data suggest an impairment of cerebrovascular function in those patients with concomittant CBF changes due to CO alterations (15/23 approximately equal to 65%). Thus, the analysis of brain perfusion in PM patients with unspecific neurological symptoms is possibly a new diagnostic feature in the future. It can be discussed whether or not indication and optimizing of pacemaker therapy has to be additionally analyzed by determination of endorgan perfusion.
Hagendorff
A
A
Medizinische Universitätsklinik und Poliklinik Abteilung Kardiologie/Angiologie Johannisallee 32 D-04103 Leipzig. hagendorff@gmx.net
Kölsch
C
C
Dettmers
C
C
Hartmann
A
A
Pfeiffer
D
D
Lüderitz
B
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D001927:Brain Diseases / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D002306:Cardiac Volume / Q000502:physiology; D002307:Cardiography, Impedance; D002560:Cerebrovascular Circulation / Q000502:physiology; D003627:Data Interpretation, Statistical; D015150:Echocardiography, Doppler; D005260:Female; D006339:Heart Rate; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D014980:Xenon Radioisotopes
D014980:Xenon Radioisotopes
Wird die Hirndurchblutung durch Veränderungen des Herzzeitvolumens beeinträchtigt? Messungen der Hirndurchblutung an Normalpersonen während Volumenbelastung und an Herzschrittmacher-Patienten bei Veränderungen der Stimulationsfrequenz.