Indirect blood pressure determination by Doppler technique in renal hypertensive cats

The Doppler ultrasonic recording technique was used to measure systolic and diastolic blood pressures indirectly in renal hypertensive cats. The accuracy of the method was evaluated by comparing indirect blood pressures from one leg of a cat with direct pressure measurements from the other leg. A linear relationship existed between indirect and direct systolic and diastolic pressures. The consistency of the method was assessed by measuring blood pressure during a 5-h monitoring period in normotensive and renal hypertensive cats. No significant variation occurred over this period. The sensitivity of the method to blood pressure changes was determined also. A significant reduction in systolic and diastolic pressure induced by hydralazine, 10 mg/kg po, was recorded during a 5-h monitoring period. The development of renovascular hypertension was followed for approximately 70 days. Systolic pressure rose in a logarithmic fashion from 160 to a maximum of 240 mmHg. It was concluded that the Doppler ultrasonic technique is a simple and reliable method for recording indirect blood pressure acutely and chronically in conscious unrestrained cats.