Pseudohypertension is found occasionally in older patients with generalized atherosclerosis leading to a stiffened brachial artery. In this condition, pressures obtained using a sphygmomanometer cuff are inappropriately high compared with intra-arterial pressures. Pseudohypertension should be considered in patients who have markedly elevated pressures in the absence of apparent target organ damage, radiologic evidence of pipe-stem calcifications in the brachial artery, severe and isolated systolic hypertension, or brachial artery pressures higher than lower extremity pressures.
In addition, watch for symptoms consistent with hypotension (ie, dizziness, fatigue) that occur in the absence of excessively low cuff measurements. In such cases, use of an infrasonic or oscillometric device appears to achieve blood pressure measurements that more closely approximate intra-arterial blood pressure than does indirect auscultatory sphygmomanometry.
In 20% to 50% of patients referred for hypertensive evaluation, blood pressure is lower, if not normal, on readings taken outside the medical environment (thus the label “white coat hypertension”). When faced with a history of variable blood pressure or out-of-office measurements that are lower or normal compared with office measurements, consider confirming the findings with home blood pressure recordings. Inexpensive, calibrated, digital devices and 24-hour ambulatory monitors are available for patients to take blood pressure recordings at home. However, physicians must feel comfortable offering treatment recommendations on the basis of readings patients have obtained at home.