Aortic blood velocity measurement in healthy adults using a simple ultrasound technique.

The normal range of aortic blood velocity has been established in 140 healthy adults using the non-invasive technique of transcutaneous aortovelography (TAV). Velocity is independent of sex, body surface area and blood pressure but declines progressively with age so that at age 70 the mean value of peak velocity is 55% of that at age 20. Integration of the area under the velocity time curve gives an indication of stroke volume and cardiac output. These indices also decrease with age as does acceleration which may reflect left ventricular function. Measurement of aortic blood velocity and its derivatives is a safe, simple and physiologically meaningful way of assessing cardiac output and function.