excerpted from Pulmonary
Hypertension: A Patient's Survival Guide - Third Edition.
You can find the definitions of many medical terms
online.Two useful sites are
MedlinePlus (www.nlm.nih.gov/medlineplus/ency)
and Hyperdictionary (www.hyperdictionary.com).
A | B | C
| D | E | F
| G | H | I
| K | L | M
| N | O | P
| R | S | T
| V | W
ACE inhibitors. ACE stands for angiotensin-converting
enzyme. ACE inhibitors help prevent the conversion inside our
bodies of angiotensin I to angiotensin II (a powerful vasoconstrictor).
Drugs in this class (e.g. Accupril) dilate arteries and let blood
flow through them with less resistance. It isn't known, yet, if
they will help some PH patients.
acute vasodilator challenge. During a right-heart catheterization,
drugs like vasodilators or prostacyclin are injected into a catheter
(that has been inserted into your heart) to see how your cardiac
output and pulmonary vascular pressures respond.
angina (two pronunciations: AN-jin-ah, an-JIGH-neh). The
word means a sense of suffocation. It is often used as shorthand
for angina pectoris, which means chest pain, or a sense of pain
or pressure about the heart. The pain may radiate down the left
arm and is caused by an insufficiency of blood to the muscle wall
of the right ventricle of the heart. The pain lasts from a few
seconds to several minutes. Symptoms are more variable in women.
angiogram (AN-jee-o-gram). An x-ray picture of blood vessels
after a radiopaque dye is injected to make the vessels more visible.
anticoagulants. "Blood thinners" that make the
blood less likely to clot. Warfarin (Coumadin, Panwarfin) is frequently
used. Another is heparin (given by IV).
arginine. We’re interested in arginine because it
is one of the things our bodies use to make nitric oxide, and
because it comes in pill form. Researchers are looking at arginine’s
possible helpfulness in reducing the symptoms of PH, especially
in PH/sickle cell anemia patients. Arginine is an essential amino
acid. “Essential” means our bodies can’t make their
own arginine, so we need to get it from the foods we eat. A normal
endothelium makes enough NO to control blood pressure, but the
endothelia of PH patients are damaged and might not be up to the
task.
atrium. One of the two upper chambers of the heart. Atria
is the plural of atrium.
atrial fibrillation. When the regular beating of an atrium
is replaced by rapid, random twitches. Less blood is therefore
pumped.
apnea (AP-nee-uh). Temporary cessation of breathing.
ascites (eh-SIGH-tees). Watery fluids in the abdominal
cavity, making you swell up.
beraprost. Seeprostanoids. A synthetic version of prostacyclin
taken in pill form.
bosentan. Seeendothelin receptor antagonists.
BMPR2. The “PH gene.” Its full name is bone morphogenetic
protein receptor II, and mutations on it have been linked to both
familial and sporadic PAH.
bronchiolitis obliterans (a.k.a. obliterative bronchiolitis,
OB). Chronic rejection of a lung or lungs after a transplant.
bronchiolitis obliterans (a.k.a. obliterative bronchiol
s, OB). Chronic rejection of a lung or lungs after a transplant.
calcium channel blockers (CCBs). Vasodilating drugs in
pill form such as nifedipine (Procardia XL, Adalat), diltiazem
(Cardizem), and Norvasc that make perhaps up to 10 to 15 percent
of PH patients feel much better by relaxing artery walls, thus
increasing blood flow to the lungs.
cardiac catheterization. A catheter is put into a blood
vessel and wiggled into your heart so doctors can learn about
the pressures in there, how your blood flows, and evaluate structural
defects.
cardiac output. The total amount of blood the heart pumps
per minute. In a healthy person this is about 5 liters; in someone
with severe PH it can be only 2-3 liters. (A human has about 5
liters [roughly 5.3 quarts] of blood per 70 kilograms [about 150
pounds] of body weight.)
catheter. A thin, flexible tube inserted into the body
for injecting or removing fluids. A surgeon puts one end of a
central line catheter into your heart; the other end stays outside
your body so you can put medicine into it.
Cialis. See phosphodiesterase inhibitors.
Classes I, II, III, and IV. See functional classifications
for PH.
collagen vascular disease (a.k.a. connective tissue disease).
Disorders affecting joints (muscles, bones, tendons, cartilage).
There is often an autoimmune component. Types associated with
PH include SLE (lupus), scleroderma, and mixed connective tissue
disease.
COPD (chronic obstructive pulmonary disease). Generalized
obstruction of the small airways in the lungs associated with
chronic bronchitis, emphysema, asthma, etc.
cor pulmonale. Enlargement of the right ventricle of the
heart. It can be caused by PH. See Chapter 1 (and the drawing
of the normal and enlarged heart).
CREST syndrome. A trigger of PH, it is a somewhat dated
term for a form of scleroderma that includes calcium deposits
in the skin, Raynaud’s phenomenon, esophageal involvement,
swollen fingers with tight skin, and skin reddened/ discolored
by blood vessels.
CT or CAT scan. An x-ray image of your insides gotten
by narrow x-rays beamed at you from several angles and run through
a computer so doctors can look at cross sections of you, including
soft tissue.
Coumadin. A trade name for warfarin, an anticoagulant
(see above).
cyanosis (sigh-ah-NO-sis). Blue skin—usually the
lips, nails, or tongue—caused by lack of oxygen.
Diastolic pressure: the bottom, lower number in your blood
pressure). See systole.
digoxin. A drug that seems to help a weak right ventricle
of the heart squeeze better.
dilate. To relax, expand.
diuretic. A chemical that helps you lose water by increasing
the amount of urine. Sometimes called a "water pill."
dyspnea (DISP-ne-eh). Labored breathing; shortness of
breath.
edema (eh-DEE-mah). Swelling.
Eisenmenger's complex. Because of a birth defect in the
heart, too much blood goes to the lungs, which results in PH.
electrocardiogram (ECG or EKG). A graphic record produced
by a device that detects the electrical activity of the heartbeat.
embolus (EM-buh-les) (plural, emboli). A clump of something
(usually a blood clot) or a bubble that has plugged up a blood
vessel. An embolism is the blockage of a vessel by an embolus.
It's usually a blood clot that has formed somewhere else and traveled
to the lungs. A thrombus is a fibrinous blood clot that obstructs
a blood vessel. If a thrombus forms in one place and moves to
another, it is called a thrombotic embolus. Sorry you asked? Just
think of them all as blood clots.
endothelin. A chemical made by the endothelium (see below).
It causes the smooth muscles in blood vessel walls to tighten
up. PAH patients have too much endothelin in their blood.
endothelin receptor antagonists. Drugs such as bosentan
(Tracleer), ambrisentan, and sitaxsentan (Thelin) taken in pill
form that keep endothelin from attaching to ETA and/or ETB receptors
in smooth muscle cells in little pulmonary arteries. This keeps
the vessels from tightening up as much. An endothelin receptor
antagonist might be dual (such as bosentan) or selective to just
one of the receptors (such as sitaxsentan or ambrisentan).
endothelium. The one-cell thick organ that lines blood
and lymph vessels, the heart, and some other things. If you spread
yours out, it would cover a football field! Endothelial cells
produce lots of chemical compounds that affect platelets and make
vessel walls relax and dilate.
enzymes. Organic catalysts made by cells that can act
inside or outside of cells, controlling the rate of chemical reactions
without being changed themselves (an enzyme can help the same
process along over and over).
epoprostenol sodium (Flolan). A prostanoid (see below)
that has several beneficial effects for most PH patients including
vasodilatation, slowing or stopping the process of fibrosis inside
little pulmonary arteries, making blood less likely to clot, etc.
It is administered through a central line catheter.
etiology (ee-tee-AWL-o-gee). The cause of a disease.
familial pulmonary arterial hypertension (FPAH). This
term is used when genetic studies and/or a family history of PPH
have shown that members of a family carry the “PH gene,”
so the disease is inherited. It used to be lumped into the old
category of primary pulmonary hypertension (PPH).
fibrin. Thrombin acts on fibrinogen to form this insoluble
hunk of protein (part of the blood coagulation process).
fibrosis (fie-BROH-sis). When inflammation or other irritants
cause a build-up of fiber-like tissue (scarring).
Flolan. See prostanoids. Flolan is the trade name
for epoprostenol sodium that is administered through a central
line catheter. The trade name Flolan is not familiar to U.K. patients,
who know the drug as prostacyclin.
functional classifications for PH. PH patients are put
into one of four possible classes; which class you are in depends
on the severity of your symptoms and may affect your choice of
treatments. You will find references in the literature to both
WHO class and to modified NYHA class (WHO Class III, for example,
or NYHA Class III). The World Health Organization (WHO) simply
modified the New York Heart Association (NYHA) categories for
generic heart failure to make them specific to PH patients. The
WHO and NYHA classes are essentially identical, except that if
you are prone to fainting, you automatically go into Class IV
under the WHO scheme. See Chapter 1 to learn which patients are
in each class.
Gaucher's (go SHAZE) disease. An inherited disease where
the lack of an enzyme leads to the accumulation of a fatty substance.
If the fatty cells accumulate in the lungs, it can lead to secondary
PH.
hemodynamics. Pressures in the heart, the movements of
the blood, and the forces involved in the circulation of blood
throughout the entire body or to particular areas of it (the heart
and lungs, in our case). Typically, hemodynamics refers to blood
pressures, cardiac output, and resistance. Some say you need a
degree in physics to fully understand it.
herpesvirus 8 (HHV-8). A newly discovered member of the
herpesvirus family, IPAH patients appear to be considerably more
likely to be infected with HHV-8 than are members of the general
population. Persons with HIV infections are also more likely to
also be infected with HHV-8. Kaposi’s sarcoma, which afflicts
some HIV patients, is similar in some ways to the plexiform lesions
found in the small pulmonary arteries of PH patients.
hypertension. Abnormally high blood pressure.
hypotension. Abnormally low blood pressure.
hypoxemia. Too low a concentration of oxygen in the blood.
This condition is a potent vasoconstrictor.
hypoxia. A low concentration of oxygen in the air that
is breathed, such as occurs aboard an airliner or high on a mountain.
idiopathic. Without a recognizable cause.
idiopathic pulmonary arterial hypertension (IPAH). Formerly
called primary pulmonary hypertension (PPH). It means pulmonary
arterial hypertension (see below) where the cause is unknown.
This category used to (and still does, in some literature) include
PH that runs in families (FPAH), PH caused by taking various drugs,
and PH triggered by diseases not directly associated with the
heart and lungs, such as liver disease
iloprost. Seeprostanoid. A stable version of prostacyclin
that is usually inhaled, although it is sometimes given by IV,
and clinical trials involving an oral form have been undertaken.
INR level. Pro-time (how long it takes your blood to clot)
translated into a standardized number, so it doesn't depend on
the reagent used and results can be compared among labs.
intravenous. Administered by injection into a vein.
ischemia (is-KEE-mee-eh). A localized, temporary reduction
in the number of oxygen-carrying red blood cells because of a
blockage of blood flow.
Kaplan-Meier estimates of survival, a.k.a. Kaplan-Meier survival
plot. These phrases appear in the captions on some graphs.
It is a statistical technique that allows researchers to estimate
survival even when all the patients in a study have not been on
a drug for the same length of time.
lesion (LEE-zhun). An area of diseased or injured tissue.
Levitra. See phosphodiesterase inhibitors.
mean pulmonary artery pressure (mean PAP). When your heart
contracts ("beats") blood pressure rises in your pulmonary
arteries (this is your systolic artery pressure). Pressure falls
when your heart relaxes between beats (your diastolic pressure).
Your "mean PAP" is a continuous average of the pressures
in your arteries throughout a complete squeeze/relax cycle. You
can find your mean PAP by multiplying your diastolic artery pressure
by two and adding the product to your systolic artery pressure,
and dividing the total by three. The result is always closer to
your diastolic pressure than to your systolic pressure.
MRI (magnetic resonance imaging). By using a strong magnetic
field and low-energy radio waves, technicians can look wherever
they want to inside your body. This is the test that often requires
you to lie inside a white tunnel, fight claustrophobia, and listen
to what sounds like sneakers tumbling in a dryer.
NHLBI. The National Heart, Lung, and Blood Institute.
This is from their website: “The Institute plans, conducts,
fosters, and supports an integrated and coordinated program of
basic research, clinical investigations and trials, observational
studies, and demonstration and education projects. Research is
related to the causes, prevention, diagnosis, and treatment of
heart, blood vessel, lung, and blood diseases; and sleep disorders.”
PHA interacts with the NHLBI through the agency’s Public
Interest Organizations group. A PHA representative (Judy Simpson,
R.N.) has served on the planning committee of this group and lobbied
hard to focus attention on PH issues.
NIH. The National Institutes of Health, a part of the
U.S. Department of Health and Human Services.
nitric oxide (NO). A potent vasodilator in gas form. (Not
the same thing as nitrous oxide, which is laughing gas.) NO is
made both in our bodies and in labs. It is being used experimentally
on some PH patients and is known to help newborn babies with persistent
pulmonary hypertension. The nice thing about NO is that it is
selective for the lungs, so it doesn't cause systemic dilation.
oximeter. A gizmo you put on your fingertip to measure
the concentration of oxygen in your blood. It’s desirable
to be at least 90 percent “saturated.”
palpitation. A sensation of rapid or throbbing heartbeats.
PAP. For our purposes, it means pulmonary artery pressure,
not a smear done by a gynecologist. Do not confuse it with your
"mean pulmonary artery pressure" (see above).
pathogenesis. The biography of a disease.
persistent pulmonary hypertension of the newborn (PPHN). When
a newborn’s arteries to the lungs remain constricted after
delivery, cutting down on blood flow to the lungs and resulting
in PH.
perfusion lung scan. After a dye that shows up on x-rays
is injected, your chest is scanned with penetrating radiation
to look for blood clots.
PH gene. SeeBMPR2. Others may yet be discovered.
phosphodiesterase (PDE-5) inhibitors. Drugs such as sildenafil
(Viagra), tadalafil, (Cialis), or vardenafil (Levitra). Approved
by the FDA and the regulatory bodies in many other countries to
treat erectile dysfunction, such drugs are now being tried (often
in combination with other PH drugs) to dilate pulmonary arteries.
The drugs are fairly selective for vessels in the penis and lungs,
so they have fewer side effects than some other options.
portopulmonary hypertension. PH associated with high blood
pressure in the liver.
primary pulmonary hypertension (PPH). Pulmonary arterial
hypertension (see below) where the cause is unknown. An imprecise,
dated term, it has now been split into two categories: idiopathic
pulmonary arterial hypertension (IPAH) (see above), and familial
pulmonary arterial hypertension (FPAH). As originally used by
doctors and researchers, the category PPH often included other
types of PAH patients as well: those who got PAH from certain
diet pills or street drugs, or who had PAH associated with the
HIV virus. When the author was not certain exactly which groups
were included in a study, PPH is put in quotes: "PPH."
prostacyclin, a.k.a. prostaglandin 12 (PG12). A prostanoid
(see below), made by our bodies that helps pulmonary blood vessels
respond to a lack of oxygen by dilating, and that PH patients
don’t make enough of. (The name comes from the prostate gland
because prostaglandin was first isolated from seminal fluid and
was thought to have been made by the prostate!) In addition to
being a vasodilator, prostacyclin may inhibit the proliferation
of smooth muscle cells.
prostanoid. Technically, a prostanoid is an end product
of the cyclo-oxygenase pathway of the metabolism of arachidonic
acid. It could be a prostaglandin or a thromboxane. Got that?
In this book, we use the term to mean a manufactured substance
much like prostacyclin (see above). Members of the prostacyclin
family of drugs are chemically very similar to one another (they
are analogs). Present analogs include epoprostenol sodium (Flolan),
treprostenol sodium (Remodulin), beraprost sodium (Dorner, Procylin),
and iloprost (Ventavis). These prostacyclin analogs help many
PH patients by dilating blood vessels, reducing clotting, slowing
down the growth of smooth muscle cells, and improving cardiac
output. Although they are all in the same class of drugs, they
are not identical, and their toxicity, side effects, and effectiveness
may differ.
pro-time. Prothrombin time; how long it takes your blood
to clot. Used to see if you are taking the right amount of warfarin.
See INR level.
pulmonary. Relating to the lungs.
pulmonary artery. The blood vessel carrying blood from
the right ventricle of the heart to the lungs, where the blood
is oxygenated.
pulmonary artery wedge pressure. A little balloon on the
tip of a catheter is inflated (wedged) in the pulmonary artery
where it can measure pulmonary vein pressures.
pulmonary function tests (PFTs). These are done to find
out how much air your lungs can hold, how well they move air in
and out, and how well they exchange oxygen. You breathe into a
device called a spirometer, or into a flow meter. The tests can
help diagnose some conditions that trigger PH.
pulmonary hypertension (PH). High blood pressure in the
pulmonary artery because of changes in the small blood vessels
in the lungs that make it harder for blood to flow through the
vessels. In this manual, the term PH includes all types of PH
unless otherwise indicated.
pulmonary thromboendarterectomy. A surgical procedure
to remove a blood clot (or clots) in a pulmonary artery in the
lungs.
pulmonary vascular resistance (PVR). This is a measure
of how difficult it is for the heart to pump blood through the
lungs. It is measured by dividing the pressure drop across the
lungs (mean pulmonary artery pressure minus left atrial ["wedge"]
pressure) by the cardiac output (blood flow per minute). PVR therefore
reflects not only PAP, but also cardiac function. If cardiac function
is good, the PVR will be lower. Some drugs, such as epoprostenol,
may not improve a patient's PAP, but the patient feels better
because his/her cardiac output has improved. PVR measurement requires
a cardiac catheterization--an echocardiogram can't do it.
pulmonary venous hypertension. PH caused by problems downstreamfrom
the air sacs in the lungs. It includes problems with the left
side of the heart, pulmonary veno-occlusive disease, compression
of the central pulmonary veins, etc.
Raynaud's (RAY-nose) phenomenon. When fingers get blue
and cold easily because of a vascular disorder. Persons with Raynaud's
are more likely to have PH than someone without this condition.
Remodulin (known as UT-15 and Uniprost in early stages
of development). See prostanoid. A prostanoid that has
a longer half-life than Flolan and needn't be refrigerated in
the pump. It is pumped into the fat under the skin; studies are
underway to get approval to deliver it through central line catheters
as well.
right atrial pressure. An index of right-heart failure.
right-heart catheterization. A thin tube with a special
tip is inserted into a neck or groin vein and threaded into the
pulmonary artery where it measures the pressures.
right ventricle. The chamber of the heart that pumps unoxygenated
blood through the pulmonary arteries and into the lungs. In PH
patients, this chamber is often enlarged, and its walls thickened.
scleroderma (skler-eh-DER-mah). Like PH, this is a progressive
and possibly fatal disease. The body's tissues slowly harden.
In some persons, only the skin is affected; in others even the
internal organs harden, including the lungs. It is not known what
causes it. Scleroderma is a common cause of PH.
secondary pulmonary hypertension (SPH). Pulmonary hypertension
that is caused by a pre-existing disease.
sildenafil. See phosphodiesterase inhibitor.
Sitaxsentan. See endothelin receptor antagonists.
sleep apnea. A disorder where someone stops breathing
long enough, while asleep, to decrease the amount of oxygen in
their blood. It can trigger mild PH.
syncope (SIN-ko-pee). Fainting because of a temporary
insufficiency of blood to the brain.
systemic. Something that affects the body generally.
systemic lupus erythematous (SLE). A progressive autoimmune
inflammatory disease of connective tissue. Its cause is unknown
and it is often fatal. A skin rash is often present that spreads
across the face in a butterfly pattern. The disease often involves
the heart and lungs. It is associated with PAH (patients with
SLE are much more likely to get PAH than people in the general
population-the general incidence of IPAH is only 1 or 2 in a million).
systole (SIS-toe-lee). The period when your heart is contracting
and squeezing blood out. Systolic pressure is the top, higher
number in your blood pressure. See diastole.
Thelin. See endothelin receptor antagonists.
Tracleer. See endothelin receptor antagonists.
vasoconstrictor. Anything that narrows the blood vessels,
thereby increasing blood pressure.
vasodilator. Anything that relaxes and widens blood vessels,
thereby decreasing blood pressure.
Viagra. See phosphodiesterase inhibitors.
VO2. A measure of the amount of oxygen (O2) that the body
takes in (and thus uses). Doctors measure peak VO2 during exercise-the
higher the number, the better the condition of your heart and
lungs. It is measured in milliliters of oxygen per minute.
warfarin. See anticoagulant.
