AHA:
Home Blood Pressure Monitoring a Plus
When
done properly, blood pressure monitoring by people at home may
be the best way to gauge daily levels, according to new guidelines
issued by the American Heart Association
(AHA).
While
readings taken in a physician's office still have an important
role to play in monitoring hypertension, "home blood pressure
monitoring tends to reflect more closely the day-to-day blood
pressure readings that people have," explains Dr. Daniel Jones,
a co-author of the new guidelines and dean of the school of
medicine at the University of Mississippi.
AHA
experts last issued blood pressure management recommendations
in 1993; the updated guidelines appear in a recent issue of
the medical journal Hypertension.
According
to the AHA, nearly one in three
US adults - about 65 million people - have high blood pressure.
High blood pressure is defined as a consistent systolic pressure
of 140 mm Hg (millimeters of mercury) or above and a diastolic
pressure at or above 90 mm Hg.
Millions
more may fall into the "prehypertension" category, with systolic
readings between 120 mm Hg and 139 mm Hg and diastolic readings
between 80 mm Hg and 89 mm Hg.
Since
the 1980s, patient home monitoring of blood pressure using store-bought
devices has become more accepted in the detection and management
of high blood pressure.
As
Dr. Jones explains, measurement of blood pressure at home may
be more accurate than in the physician's office, since readings
sometimes rise in the presence of healthcare providers.
"Almost
everyone has what we call the 'white-coat effect' when they
go into a physician's office - a response our brains have to
being in a nervous situation," he says. "Home monitoring allows
the measurement of blood pressure in an atmosphere that more
closely measures daily activity."
Many
studies in the last decade have confirmed that a combination
of home and office monitoring is the best means of getting an
accurate picture of hypertension risk, Dr. Jones notes.
"There's
been lots of new data that has been meaningful about home blood
pressure monitoring," he remarks. "That's reflected in these
new guidelines."
The
new guidelines strongly support home monitoring, as long as
it is done properly, Dr. Jones says. Appropriate arm cuff size
remains a key component in any home blood pressure reading,
he explains.
"There's
a strong emphasis on proper cuff size in the recommendations,
because of the growing problem of obesity in this country,"
Dr. Jones notes. "More and more, as our bodies get bigger our
arms get bigger, too, so larger and larger percentages of people
need a larger-sized cuff for accurate measurement."
Dr.
Jones says that decisions on the timing and method of home blood
pressure monitoring is best left up to a patient and his or
her physician.
However,
in a statement, the AHA recommends
that "ideally, blood pressure should be taken after several
minutes' relaxation, when a person is comfortably seated in
a chair, legs uncrossed, not talking, back and arm supported,
and the cuff placed on bare skin."
Dr.
Jones says the AHA does not endorse
any particular brand of home monitor, but it does recommend
that devices carry the seal of approval of the Association
for the Advancement of Medical Instrumentation (AAMI).
The US Food and Drug Administration (FDA)
delegates testing and certification of home blood pressure monitors
to the AAMI, Dr. Jones says.
He
stresses that the new recommendations do not in any way diminish
the importance of blood pressure readings taken in a physician's
office.
"Office
blood pressure measurement is a critical part of what's necessary
for the good management of blood pressure problems," Dr. Jones
says.
Always
consult your physician for more information.
|
Blood
pressure, measured with a blood pressure cuff and stethoscope
by a nurse or other healthcare provider, is the force of the
blood pushing against the artery walls.
Each
time the heart beats, it pumps blood into the arteries, resulting
in the highest blood pressure as the heart contracts. One cannot
take his or her own blood pressure unless an electronic blood
pressure monitoring device is used. Electronic blood pressure
monitors may also measure the heart rate, or pulse.
Two
numbers are recorded when measuring blood pressure. The higher
number, or systolic pressure, refers to the pressure inside
the artery when the heart contracts and pumps blood through
the body.
The
lower number, or diastolic pressure, refers to the pressure
inside the artery when the heart is at rest and is filling with
blood.
Both
the systolic and diastolic pressures are recorded as "mm Hg"
(millimeters of mercury). This recording represents how high
the mercury column is raised by the pressure of the blood.
High
blood pressure, or hypertension, directly increases the risk
of coronary heart disease (heart attack) and stroke (brain attack).
With
high blood pressure, the arteries may have an increased resistance
against the flow of blood, causing the heart to pump harder
to circulate the blood.
According
to the National Heart, Lung, and Blood
Institute (NHLBI), high blood pressure for adults is
defined as:
140
mm Hg or greater systolic pressure
and
90
mm Hg or greater diastolic pressure
In
an update of NHLBI guidelines
for hypertension in 2003, a new blood pressure category was
added called prehypertension:
120
mm Hg - 139 mm Hg systolic pressure
and
80
mm Hg - 89 mm Hg diastolic pressure
The
new NHLBI guidelines now define
normal blood pressure as follows:
Less
than 120 mm Hg systolic pressure
and
Less
than 80 mm Hg diastolic pressure
These
numbers should be used as a guide only. A single elevated blood
pressure measurement is not necessarily an indication of a problem.
Your
physician will want to see multiple blood pressure measurements
over several days or weeks before making a diagnosis of hypertension
(high blood pressure) and initiating treatment.
A
person who normally runs a lower-than-usual blood pressure may
be considered hypertensive with lower blood pressure measurements
than 140/90.
Always
consult your physician for more information. |
