[Effect of frequent ventricular extrasystole on brain circulation in patients with coronary heart disease].
Animal experiments using the microsphere method indicate a 8% reduction of mean cerebral blood flow during parasystolic rhythm induced by ventricular pacing in comparison to a control group with sinus rhythm. The parasystolic rhythm causes changes of systemic arterial blood pressure, which are comparable to the hemodynamic effects of frequent premature ventricular contractions. Because a reduction of cerebral blood flow induced by frequent premature ventricular beats can be assumed by the results of the laboratory investigations, cerebral blood flow was determined in a clinical study in 19 coronary artery disease patients and in 11 healthy, age-adjusted volunteers using the 133Xenon-inhalation method, in order to investigate the effect of ventricular ectopics on cerebral perfusion. Simultaneously Holter monitoring was performed during cerebral blood flow measurements. Cerebral blood flow was estimated by the initial slope index, which is calculated from the early decay of the clearance curve, and by the mean cerebral blood flow index, which is calculated by the stochastic method. Grey matter blood flow is estimated by the two-compartment analysis. Cerebral blood flow in coronary artery disease patients is reduced versus controls. The initial slope indices were 45.2 +/- 5.1 s-1 and 57.4 +/- 7.2(-1), respectively (p < 0.01). In patients with frequent ventricular ectopic activity (739/h) an additional reduction of cerebral blood flow was observed. The initial slope index was 42.6 +/- 6.3 s-1 (p < 0.01). The reduction of cerebral blood flow in coronary artery disease patients is partially due to the coincidence of coronary and cerebral artery disease. Frequent ventricular premature contractions might cause an additional reduction.
Hagendorff
A
A
Medizinische Universitätsklinik Bonn.
Dettmers
C
C
Wirtz
P
P
Block
A
A
Hartmann
A
A
Lüderitz
B
B
D000328:Adult; D000368:Aged; D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D005117:Cardiac Complexes, Premature / Q000503:physiopathology*; D003327:Coronary Disease / Q000503:physiopathology*; D015716:Electrocardiography, Ambulatory; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D051381:Rats; D012039:Regional Blood Flow / Q000502:physiology; D014980:Xenon Radioisotopes
D014980:Xenon Radioisotopes