Chapter 11 HypertensionBP should be measured by an appropriately
trained health care provider with a properly cali-
brated and validated BP instrument, usually either a
mercury or aneroid sphygmomanometer. Patients
should be seated comfortably and quietly for at least
5 minutes in a chair. The “ideal” sphygmomanom-
eter cuff should have a bladder length that is 80%
and a width that is at least 40% of arm circumfer-
ence (a length-to-width ratio of 2 : 1) [19]. A cuff
that is too small for the arm size will overestimate
the true BP.
The cuff should be infl ated above the systolic BP,
and then should be defl ated at 2 to 3 mm/s. The fi rst
and last audible sounds signal the systolic and dia-
stolic BP. Phase 1 (systolic) and phase 5 (diastolic)
Korotkoff sounds are best heard using the bell of the
stethoscope over the brachial artery in the antecubi-
tal fossa. The BP should be read to the nearest
2 mm Hg, and the tendency to round off the
numbers to the nearest 5 or 10 mm Hg (“digit pref-
erence”) should be resisted. At least two readings
should be taken at intervals of at least one minute,
and the average of those readings should be recorded
as the patient’s BP. Sometimes it is useful to measure
BP in the standing position, and to compare that
with values obtained in the sitting or supine posi-
tion, especially in the evaluation of dizziness or
syncope.
Automated oscillometric BP measuring devices
are increasingly being used in offi ce BP measure-
ment, as well as for home and ambulatory moni-
toring. The potential advantages of automated
measurement in the offi ce are the elimination of
observer error or digit preference, minimizing the
white coat effect, and increasing the number of read-
ings. The main disadvantages are the error inherent
in the oscillometric method and the fact that epide-
miologic data are mostly based on auscultatory BP
measurements.
The standard type of monitor for home use is now
an oscillometric device that records pressure from
the brachial artery [20]. An up-to-date list of
validated monitors is available [21]. Home- or
self-monitoring has numerous advantages over
ambulatory monitoring, principal among which are
that it is relatively cheap and provides a convenient
way for monitoring BP over long periods of time. It
may also improve therapeutic compliance and BP
control. The American Society of Hypertension rec-
ommended 135/85 mm Hg as the upper limit of
normal for home and ambulatory BP [22].
Devices are now available that have the capacity
to store readings in their memory and then transmit
them via the telephone to a central server computer,
and then to the health care provider. They have the
potential to improve patient compliance and hence
BP control. Readings taken with a telemonitoring
system may correlate more closely than clinic read-
ings with ambulatory BP [23].
Ambulatory blood pressure (ABP) monitoring is
a noninvasive, fully automated technique in which
BP is recorded over an extended period of time, typi-
cally 24 hours. It has been used for many years as a
research procedure and has been approved by the
Centers for Medicare and Medicaid Services for
reimbursement of a single recording in patients with
suspected white coat hypertension (WCH), defi ned
as high clinic pressures and normal pressures in
other settings, and no evidence of target organ
damage. The most common applications are to iden-
tify individuals with WCH, or with a BP that is not
lower during sleep than awake (“non-dipping
pattern”), e.g. in many patients with diabetes, or
patients with apparently refractory hypertension but
relatively little target organ damage, suspected auto-
nomic neuropathy, and patients in whom there is a
large discrepancy between clinic and home measure-
ments of BP. It is also helpful to assess patients with
apparent drug resistance, hypotensive symptoms
with antihypertensive medications, and episodic
hypertension. The ABP criteria for the diagnosis of
hypertension are a mean BP of more than
135/85 mm Hg while awake and more than
120/75 mm Hg during sleep. In most individuals, BP
decreases by 10% to 20% during the night; those in
whom such decreases are not present (“non-dippers”)
are at increased risk for cardiovascular events.Patient evaluation [1,2]
Evaluation of patients with documented hyperten-
sion has three objectives: (1) to reveal identifi able
causes of high BP (Table 11.3); (2) to assess the pres-
ence or absence of target-organ damage (Table
11.4); and (3) to assess lifestyle and identify other
cardiovascular risk factors or concomitant disorders
that may affect prognosis and guide treatment
(Table 11.5). The data needed are acquired through