Relationship between blood flow velocity and cerebral circulation time in patients with intracranial aneurysm

Franklin, Karl A., Erik Sandström, Göran Johansson, and Eva M. Bålfors. Hemodynamics, cerebral circulation, and oxygen saturation in Cheyne-Stokes respiration. J. Appl. Physiol. 83(4): 1184–1191, 1997.—Because cardiovascular disorders and stroke may induce Cheyne-Stokes respiration, our purpose was to study the interaction among cerebral activity, cerebral circulation, blood pressure, and blood gases during Cheyne-Stokes respiration. Ten patients with heart failure or a previous stroke were investigated during Cheyne-Stokes respiration with recordings of daytime polysomnography, cerebral blood flow velocity, intra-arterial blood pressure, and intra-arterial oxygen saturation with and without oxygen administration. There were simultaneous changes in wakefulness, cerebral blood flow velocity, and respiration with accompanying changes in blood pressure and heart rate ∼10 s later. Cerebral blood flow velocity, blood pressure, and heart rate had a minimum occurrence in apnea and a maximum occurrence during hyperpnea. The apnea-induced oxygen desaturations were diminished during oxygen administration, but the hemodynamic alterations persisted. Oxygen desaturations were more severe and occurred earlier according to intra-arterial measurements than with finger oximetry. It is not possible to explain Cheyne-Stokes respiration by alterations in blood gases and circulatory time alone. Cheyne-Stokes respiration may be characterized as a state of phase-linked cyclic changes in cerebral, respiratory, and cardiovascular functions probably generated by variations in central nervous activity.

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Cerebral Blood Flow Velocity in the Human Newborn: The Value of Its Determination

PEDIATRICS ◽

10.1542/peds.70.1.147a ◽

1982 ◽

Vol 70 (1) ◽

pp. 147-152

Author(s):

Joseph J. Volpe ◽

Jeffrey M. Perlman ◽

Alan Hill ◽

Joseph B. McMenamin

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Brain Injury ◽

Flow Velocity ◽

Blood Flow Velocity ◽

Cerebral Circulation ◽

Cerebral Blood Flow Velocity ◽

Doppler Frequency ◽

Systemic Hemodynamic ◽

Human Newborn

An ultrasonic technique based on measurement of the Doppler frequency shift produced by the movement of red blood cells in an insonated vessel has been useful for measurement of cerebral blood flow velocity in the newborn. When the transducer is applied to the anterior fontanel, flow velocity in each anterior cerebral artery can be determined noninvasively. Reliable application ofthe technique requires utilization of both the audible and visible signals produced by the instrument. Experience and awareness of the anatomy are also important in interpretation. Serial measurements of cerebral blood flow velocity have provided useful information concerning changes in the cerebral circulation under important neonatal circumstances. Examples of the latter include PDA, pneumothorax, hydrocephalus, and hyperviscosity. Most of the changes in the cerebral circulation appear to reflect directly systemic hemodynamic changes. This relation between cerebral and systemic hemodynamic events is compatible with other observations, indicating that in the human newborn—particularly the infant most at risk for hypoxic-ischemic and/or hemorrhagic brain injury—the cerebral circulation is pressure passive. Indeed, the changes in the cerebral circulation observed so far with the Doppler technique may have important implications for the genesis of neonatal ischemic and hemorrhagic brain injury.

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Episodes of Apnea and Bradycardia in the Preterm Newborn: Impact on Cerebral Circulation

PEDIATRICS ◽

10.1542/peds.76.3.333 ◽

1985 ◽

Vol 76 (3) ◽

pp. 333-338 ◽

Cited By ~ 1

Author(s):

Jeffrey M. Perlman ◽

Joseph J. Volpe

Keyword(s):

Heart Rate ◽

Blood Flow ◽

Flow Velocity ◽

Blood Flow Velocity ◽

Cerebral Circulation ◽

Cerebral Blood Flow Velocity ◽

Base Line ◽

Diastolic Flow ◽

Arterial Blood ◽

Severe Bradycardia

The effect of episodes of apnea with bradycardia on cerebral circulation was studied during 101 episodes in 15 premature infants. The objectives of the study were to determine whether important alterations occur in cerebral hemodynamics with apnea and bradycardia cardia and whether such alterations relate to systemic hemodynamic events. The transcutaneous Doppler technique was used to measure blood flow velocity in the anterior cerebral arteries. With episodes of apnea complicated by mild-to-moderate bradycardia (heart rate <120 or >80), a decrease in diastolic flow velocity was noted with little or no change in systolic flow velocity. With episodes complicated by severe bradycardia (heart rate <80), the diastolic flow velocity fell to the electronic base line, and a progressive decrease in systolic flow velocity also was observed. Accompanying the changes in cerebral blood flow velocity were similar changes in arterial blood pressure. These data suggest potential deleterious hypoxic-ischemic effects on brain from apnea with severe bradycardia in the preterm infant.

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State of cerebral circulation in neurosensoral deaf in combination stable voltage stenocardia

Russian otorhinolaryngology ◽

10.18692/1810-4800-2021-6-20-25 ◽

2021 ◽

Vol 20 (6) ◽

pp. 20-25

Author(s):

S. S. Arifov ◽

◽

D. А. Каlandarova ◽

Keyword(s):

Blood Flow ◽

Hearing Loss ◽

Sensorineural Hearing Loss ◽

Flow Velocity ◽

Blood Flow Velocity ◽

Cerebral Circulation ◽

Sensorineural Hearing ◽

Duplex Scanning ◽

Exertional Angina ◽

Antianginal Drugs

The aim of this study was to study the state of cerebral circulation using duplex scanning of extra- and intracranial vessels in sensorineural hearing loss in combination with stable exertional angina. The study included 43 patients with diagnosed sensorineural hearing loss in combination with stable exertional angina at the age of 30 to 63 years, who had not previously received antianginal drugs. With the help of color duplex scanning, cerebral circulation in the extra- and intracranial vessels was studied. 19 people (44,2%) had the first degree, and 16 people (37,2%) had the second degree of hearing loss. In 9,3% of cases, the average air conduction rate in patients did not reach 26 dB. In 9,3% of patients, an increase in thresholds was observed only in the ultra-high-frequency zone (10 000–20 000 Hz). In patients with sensorineural hearing loss in combination with stable exertional angina, there was a change in the linear blood flow velocity in the extra- and intracranial vessels. In the common carotid and vertebral arteries, an increase in the linear blood flow velocity and the Gosling pulsative index was revealed. In the intracranial segment, a decrease in the linear velocity of blood flow in the vertebral and main arteries was found, which in 42% of patients was combined with a decrease in the anatomical reserve of blood vessels due to a disconnected variant of the structure of the circle of Willis and / or the presence of obstructed venous outflow.

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