High Blood Pressure / Hypertension

Monitoring Adequacy of Blood Pressure Control

By Cardiologist on August 13th, 2011

Treatment should be targeted to lower blood pressure levels to below 140/90 inmHg in all patients, and below 130/85 mmHg in diabetic patients and those with renal failure or congestive heart failure. With some agents, such as diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and β-blockers, a decrease in blood pressure may be expected only after 2-4 wk of treatment. Therefore, the first visit after initiating antihypertensive treatment should be scheduled 4 wk after beginning treatment. If the desired target blood pressure is not achieved, increasing the dose or adding a second agent is recommended. Physicians and patients should understand that achieving blood pressure control may take a few months. The risk of mild hypertension would take years to manifest itself, and therefore a few months of uncontrolled blood pressure does not pose a major risk and should not alarm the patient. If blood pressure is not well controlled with three agents after 3 mo of treatment, further evaluation should be done, or referral to a specialist is recommended, to exclude secondary hypertension.

Follow-up should include measurements of heart rate, blood pressure, and body weight. Heart rate is important to guide antihypertensive treatment. A young patient with relative tachycardia is a good candidate for a β-blocker and a bad candidate for dihydropyridine calcium antagonists. Moreover, dose adjustment of β-blockers should be based on heart rate.

Blood pressure should be measured in the sitting position on the arm with the higher blood pressure levels. In some patients, particularly older persons and those with orthostatic symptoms, monitoring should include blood pressure measurement in the seated position and after standing quietly for 2-5 min.

Blood pressure control should be based on measurements obtained in the late afternoon or evening to monitor control across the day and in the early morning, at trough effect, to ensure adequate modulation of the surge blood pressure after rising. This may pose a problem for many patients who are unable to come to the clinic early in the morning. To overcome this problem, self-measurements at home can be used. Self-measurements can be done with either validated electronic devices or aneroid sphyg-momanometers with appropriate-sized cuffs that have proven to be accurate according to standard testing. Two or more readings separated by 2 min should be taken. If the first two readings differ by more than 5 mmHg, additional readings should be obtained. Self-measurements may also identify patients with white coat hypertension (which appears in about 20-25% of hypertensive patients). Indeed, levels reported by patients at home tend to be lower than the actual levels, but Sega et al. showed that home measurements are reliable and close to values achieved by 24-h monitoring. To increase reliability of home measurements, one can use an electronic device that stores blood pressure levels, heart rate, date, and hour. The devices should be checked periodically for accuracy against a mercury sphygmomanometer. There is no universally agreed-on upper limit of normal home blood pressure, but readings of 135/85 mmHg or greater should be considered elevated. Despite the advantage of self-measurements at home, this method should not be recommended to patients who suffer from panic attacks or anxiety and stress, who may overuse the device and can become addicted to it. This phenomenon may by itself increase the level of panic and stress and thereby increase blood pressure.

Once blood pressure is stabilized at the desirable range, follow-up at 3- to 6-mo intervals with measuring blood pressure once a month is generally appropriate. If an abrupt rise in blood pressure occurs in a medicated patient whose blood pressure was well controlled and stable over along period, repeated blood pressure measurement should be performed before any decision is made. Usually the increase in blood pressure is transient and related to an underlying cause.

Table Causes of blood pressure Increase in a Stable Medicated Patient

Therefore, it is recommended not to change the antihypertensive regimen immediately, but to try to identify the cause and treat it accordingly. Only when no treatable underlying cause is identified should the antihypertensive regimen be modified.

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