Cerebral hemodynamics during carotid massage in patients with carotid sinus syndrome.
The effect of cardioinhibition and/or vasodepression on cerebral hemodynamics assessed by transcranial Doppler has been investigated during carotid massage in 11 patients (62-87 years, mean age 72) with carotid sinus syndrome. The patients were tested in the OOO mode (n = 11) with six tested in the DDD mode. Carotid massage in the OOO mode decreased mean arterial pressure by 44% (P < 0.01) and mean cerebral blood flow velocity by 50% (P < 0.01). Although not significant, cerebrovascular resistance increased transiently by 17% during massage, then decreased by 31% upon recovery. Carotid massage in the DDD mode decreased arterial pressure by 30% (P < 0.01), cerebral blood velocity by 23% (P < 0.01), and resistance by 15% (P < 0.05). The decreased cerebral perfusion induced by cardioinhibition and/or vasodepression results from the delayed onset of cerebral autoregulation. Pacing in the DDD mode temporarily assists the critical period preceding the onset of cerebral autoregulation that plays a key role in preventing the deleterious effects of vasodepression.
Leftheriotis
G
G
Laboratory of Physiology, Medical School and Teaching Hospital of Angers, France. georges.leftheriotis@univ-angers.fr
Rozak
P
P
Dupuis
J M
JM
Victor
J
J
Tadeï
A
A
Saumet
J L
JL
D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D002304:Cardiac Pacing, Artificial / Q000379:methods; D002346:Carotid Sinus / Q000503:physiopathology*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008405:Massage; D010138:Pacemaker, Artificial; D013575:Syncope / Q000503:physiopathology* / Q000628:therapy; D013577:Syndrome; D017585:Ultrasonography, Doppler, Transcranial