TION TESTSto assess LUNG CAPACITYand the ability of
the lungs to exchange oxygen and carbon dioxide,
and CARDIAC CATHETERIZATIONto measure the pres-
sure within the pulmonary arteries.
Treatment Options and OutlookDoctors may prescribe medications such as
vasodilators and calcium channel blockers to help
relax the arteries in the lungs and lower resistance
to the flow of blood, anticoagulant medications to
lower the risk for blood clots, and diuretics
(“water pills”) to reduce edema. Research suggests
that many people who have pulmonary hyperten-
sion have elevated levels of endothelin, an amino
acid compound (peptide) naturally present in the
walls of the arteries that causes them to constrict.
Whether this elevation is a consequence or cause
of pulmonary hypertension remains unclear,
though its recognition has resulted in the develop-
ment of medications called endothelin receptor
antagonists. These medications relieve the symp-
toms of pulmonary hypertension by relaxing the
walls of the arteries in the lungs. Oxygen therapy
can improve the amount of oxygen that enters the
blood circulation.
Treatment targets the underlying cause, to the
extent possible, when pulmonary hypertension is
secondary, as well as aims to lower pulmonary
blood pressure. However, any damage that occurs
to the heart is generally irreversible. PPH is pro-
gressive and as yet there is no curative treatment.
Early diagnosis and medications can slow PPH’s
progression and improve QUALITY OF LIFE. Lifestyle
modifications, such as WEIGHT LOSS AND WEIGHT
MANAGEMENT, SMOKING CESSATION, and regular phys-
ical activity within the capacity the person’s car-
diovascular function allows, help keep the
cardiovascular system functioning as efficiently as
possible. LUNG TRANSPLANTATIONmay be a treatment
option for younger people when PPH is the only
significant health condition. People who also have
severe heart failure may benefit from a combined
heart–lung transplantation. These are complex
operations, however, and donor organs are
extremely limited.
Risk Factors and Preventive Measures
The risk factors for secondary pulmonary hyper-
tension are the conditions that may cause it. Early
diagnosis and appropriate treatment for these con-
ditions helps prevent pulmonary hypertension
from developing. Because doctors do not know
what causes PPH, they cannot identify clear risk
factors.
See also CARDIOVASCULAR DISEASE PREVENTION;
MEDICATIONS TO TREAT CARDIOVASCULAR DISEASE;
ORGAN TRANSPLANTATION; OXYGEN–CARBON DIOXIDE
EXCHANGE.pulmonary veins The large blood vessels that
bring blood to the left side of theHEARTfrom the
LUNGS. The main pulmonary veins arise from the
lungs and branch immediately into the right pul-
monary vein and the left pulmonary vein. The
right pulmonary vein carries blood from the right
lung and the left pulmonary vein carries blood
from the left lung. The pulmonary veins are the
only veins in the body that transport oxygenated
blood.
For further discussion of the pulmonary veins
within the context of cardiovascular structure and
function, please see the overview section “The
Cardiovascular System.”
See alsoAORTA; VENA CAVA.pulse The pattern of contractions in the arteries
as BLOODpasses through them, typically synchro-
nized with the contractions of the HEART. Where
an ARTERYis close to the surface, it is possible to
feel the pulse by applying pressure with two fin-
gers (but not the thumb, which has its own per-
ceptible pulse).PULSE POINTS
Artery Body Location
abdominal aorta solar plexus area of the abdomen
brachial inside of the upper arm
carotid each side of the neck, below the jaw
femoral groin
pedal top of the foot
popliteal behind the knee
radial wrist, below the base of the thumb
temporal side of the forehead
tibial inside of the lower leg, behind the inner
ankle
ulnar wrist, at the base of the hand on the
opposite side from the thumbpulse 99