Measurement of phasic carotid artery flow velocity in man

Abstract

The flow velocity pattern in the common and internal carotid artery is described in seventeen patients using the catheter tip Doppler ultrasonic flowmeter telemetry system. The normal flow velocity pattern in the internal carotid arteries is pulsatile; it is characterized by a major systolic wave which occurs during ventricular systole, representing forward flow. The flow velocity pattern in the internal carotid artery, although phasic, is continuous throughout the cardiac cycle. Ventricular tachycardia results in marked reduction in carotid artery flow velocity, with variation in beat to beat flow velocity. With atrial fibrillation, there is significant variation in beat to beat peak flow velocity, and this is quite pronounced at a rapid heart rate. These variations have a direct correlation with the cycle length and emphasize the importance of diastolic filling time. This device may be used to study instantaneous phasic carotid artery flow velocity in conscious, unanesthetized man without the need for vessel exposure, and has potential value in the study of obstructive disease of the carotid arteries in patients with cerebral vascular insufficiency. The flow velocity pattern in the common and internal carotid artery is described in seventeen patients using the catheter tip Doppler ultrasonic flowmeter telemetry system. The normal flow velocity pattern in the internal carotid arteries is pulsatile; it is characterized by a major systolic wave which occurs during ventricular systole, representing forward flow. The flow velocity pattern in the internal carotid artery, although phasic, is continuous throughout the cardiac cycle. Ventricular tachycardia results in marked reduction in carotid artery flow velocity, with variation in beat to beat flow velocity. With atrial fibrillation, there is significant variation in beat to beat peak flow velocity, and this is quite pronounced at a rapid heart rate. These variations have a direct correlation with the cycle length and emphasize the importance of diastolic filling time. This device may be used to study instantaneous phasic carotid artery flow velocity in conscious, unanesthetized man without the need for vessel exposure, and has potential value in the study of obstructive disease of the carotid arteries in patients with cerebral vascular insufficiency.