Common Terms and Acronyms Used with PH

Chest pain that originates in the heart.

Blood vessel that delivers oxygen rich blood from the left ventricle to the body; it is the largest blood vessel in the body.

Arterial blood gas - ABG
A blood test that measures the concentrations of oxygen and carbon dioxide in the arterial blood. Usually, the blood sample is taken from the radial artery at the wrist.

Atrial fibrillation & a extremely rapidly, thus causing the ventricles to contract faster and less efficientltrial flutter
Atrial fibrillation and atrial flutter are very fast electrical discharge patterns that make the atrial chamber of the heart contracty than normal. In fibrillation, the atrial rhythm is irregular, so the ventricular rhythm is also irregular; in flutter, the atrial and ventricular rhythms usually are regular.

One of the two receiving chambers of the heart.  The left atrium receives oxygen-rich blood from the lungs. The right atrium receives oxygen-depleted blood from the body.

Calcium Channel Blocker - CCB
A treatment for PH; tablets.

Cardiac output 
Total amount of blood being pumped by the heart over a particular period of time.

Thin flexible tube.

Use of catheter to study heart and lung function. Pictures, blood samples, and pressures are recorded.

Central line catheter
A surgically implanted line that goes directly into the heart. The end, which remains outside the body, is connected to IV medication lines.

Clinical trials 
Medical studies of patients that evaluate the effectiveness of treatments.

Tighten; narrow.

CREST syndrome 
A less severe form of scleroderma, named for its symptoms: calcium deposits in the skin and throughout the body, Raynaud's phenomenon, esophageal dysfunction, sclerodactylly (skin damage on the fingers) and telanggieectasia (spider veins). People who have CREST syndrome can develop pulmonary hypertension.

A bluish color in the skin because of lack of adequate oxygen.

Diastolic pressure 
The lowest pressure to which blood pressure falls between contractions of the ventricles.

Relax; expand.

A sterile solution used for reconstituting Flolan powder.

Dual ERA
An endothelin receptor antagonist (ERA) that blocks both the ET-A and ET- B endothelin receptors

Difficulty breathing, or shortness of breath.

A non-invasive diagnostic procedure using ultrasound waves to study the heart. It is used to assess disorders of cardiac muscle function or valve function, or other abnormalities such as elevated pulmonary pressure.

Endothelial cells 
Lining of organs of blood flow.

A chemical produced naturally by the body. In healthy amounts, it plays an important role in regulating blood flow. In conditions such as Pulmonary Arterial Hypertension (PAH), excess endothelin is produced, tightening and narrowing blood vessels and affecting the blood pressure in the lungs.

Endothelin receptor antagonist (ERA)
A new class of drug that blocks endothelin receptors and limits the harmful effects of excess endothelin in PAH. There are two main kinds of ERAs: selective and dual ERAs.

Endothelin receptors
In order to have an effect, endothelin must connect with an endothelin receptor. There are two main endothelin receptors: ET-A and ET-B. Endothelin receptor antagonists (ERAs) work by blocking one or both of the endothelin receptors. It seems clear that ET-A tightens and narrows blood vessels, but the role of ET-B is a matter of debate among researchers.

The thin layer of cells that lines blood vessels. It is the primary producer
of endothelin.

Swelling due to too much fluid.

U.S. Food and Drug Administration; the regulatory agency which approves new drugs for use.

Scarring of tissue, making it stiffer and not as functional as normal tissue.

A treatment for PH; continuous infusion of prostacyclin via battery operated pump.

One pump of the heart.

Excessive reaction of tissue.

Abnormally high pressure.

Abnormally low pressure.

Inadequate amounts of available oxygen in the blood

International Normalization Ratio value. A standardized measure of blood clotting time/ratio. Prothrombin time blood test results are reported in seconds and can vary depending upon the reagent used; the INR result is independent of the reagents used and is therefore a more uniform test result. Therapeutic INR is usually considered to be 2.0 to 3.5 in most institutions.

Lung volume 
The amount of air the lungs hold.

Mean blood pressure 
The average blood pressure.

NYHA Class I - IV
New York Heart Association functional classification. An assessment of physical limitations and symptoms of patients with heart disease. This classification system has been modified slightly by the WHO World Symposium on PH to describe pulmonary hypertension patients. Briefly stated:

Nuclear testing 
Use of radioactive medication to trace the blood flow- usually done with very low level of radiation exposure (equal to chest x ray).


A device for measuring or monitoring oxygen concentration in the blood using an electrode placed on a finger or an earlobe--a procedure called oximetry.

Oxygen saturation
The amount of available oxygen in the blood. The percentage of oxygen concentration is referred to as O2 Sats.

Primary Care Physician

PH Specialist
A physician, usually a cardiologist or pulmonologist, who has diagnosed and treated a large number of PH patients.  A PH specialist is familiar with current diagnostic methods and treatments for PH.

The sensation of rapid heartbeats.

Flow of liquid through a network of vessels or tissue.

Primary pulmonary hypertension - PPH 
Unexplained cases with no known cause (idiopathic).

A synthetic form of prostaglandin.  It is also known as epoprostenol. Flolan and Remodulin are two forms of prostacyclin.

A steroid that is produced naturally in the body in a normally healthy person. It causes blood vessels in the lungs to relax and allow blood to flow through them more easily.

Medical term for the lungs.

Pulmonary arterial hypertension - PAH
Pulmonary arterial hypertension (PAH): One of five categories of pulmonary hypertension; this category includes PH of unknown origin. Most kinds of pulmonary hypertension are PAH. PAH constricts or contracts the arterioles of the lungs, which are small, muscular branches of arteries within the lungs. When they are constricted, they increase resistance to blood flow, and blood pressure in the pulmonary artery increases.

Pulmonary artery - PA 
Blood vessel delivering blood to the lung from the right side of the heart.

Pulmonary Artery Pressure – PAP
Blood pressure in the artery carrying blood from the heart to the lungs.

Pulmonary Edema
Fluid in the lung(s)

Pulmonary Function Test – PFT
A group of tests to measure the lungs' capacity to hold air as well as their ability to move air in and out and to exchange oxygen and carbon dioxide.

Pulmonary Hypertension - (PH)
Abnormally high blood pressure in the lungs. The small vessels that supply blood to the lungs constrict, making it harder for blood to get to the lungs and forcing the heart to work harder. This term includes PAH and all other kinds of pulmonary hypertension, such as PH associated with disorders of the respiratory system, due to chronic thrombotic or embolic disease, or due to disorders directly affecting the pulmonary blood vessels.

Pulse oximeter
A fingertip device for measuring oxygen concentration in the blood.

A synthetic, stable form of prostacyclin that is administered under the skin rather than into the bloodstream.

Right Heart Catheterizations - RHC 
Use of catheter to study heart and lung function. Pictures, blood samples, and pressures are recorded. Considered the "gold standard" for diagnosis of pulmonary hypertension.

Secondary pulmonary hypertension - SPH 
Cases that result from another disease that elevates the pressure in the arteries of the lungs.

Selective ERA
An endothelin receptor antagonist (ERA) that blocks only the ET-A endothelin receptor. ET-A plays a significant role in the constricting of blood vessels.

An oral endothelin receptor antagonist (ERA) currently in clinical trials. It is a selective ERA.

Sleep apnea 
A condition in which the patient has short periods of not breathing during sleep.

Smooth muscle 
Usually the middle layer of an artery, which contains elastic and performs automatic tasks, such as tightening blood vessels.

Short of Breath.

Specialty pharmacy distributor
Providers of pharmaceutical services for patients with chronic diseases or genetic disorders that require high-cost, complex therapies.

Subcutaneous infusion
A drug treatment delivery method that infuses the drug under the skin by means of a small pump.  Remodulin is delivered in this manner.

Fainting, temporary loss of wakefulness.

Affects all of the body.

Systolic pressure 
The highest pressure to which blood pressure rises with pumping of the heart.

An abnormally rapid and uneven heartbeat

Targeted ERAs
An endothelin receptor antagonist (ERA) that blocks only the ET-A endothelin receptor. ET-A plays a significant role in the constricting of blood vessels.

A procedure in which pleural effusion (fluid that has collected abnormally in the space around the lungs) is removed with a needle and syringe, so it can be analyzed, and also to relieve shortness of breath caused by lung tissue compression.

Tracleer (formerly Bosentan) 
The first oral endothelin receptor antagonist (ERA) approved for use in PAH patients with WHO Class III or IV symptoms. It is a dual ERA.

Spasms of the jaw muscles; difficulty opening the mouth.

The name of Remodulin while it was in clinical trials.

Something (drug or action) that narrows and tightens the blood vessels.

Something (drug or action) that widens and relaxes the blood vessels.

One of the two pumping chambers of the heart. The right ventricle receives oxygen -poor blood from the right atrium and pumps it to the body through the aorta.

Viagra (Sildenafil)
An oral drug treatment for PH in clinical trials in Sydney, Australia.  It is hoped that Viagra will increase the capacity to produce nitric oxide, which decreases the elevated pulmonary artery pressure minimizing the symptoms associated with PAH.


Chest pain that originates in the heart.

Aorta Blood

Vessel that delivers oxygen-rich blood from the left ventricle to the body; it is the largest blood vessel in the body.


One of the two receiving chambers of the heart. The right atrium receives oxygen-poor blood from the body. The left atrium receives oxygen-rich blood from the lungs. The plural of atrium is atria.

Blood Pressure

The pressure of blood against the walls of a blood vessel or heart chamber. Unless there is reference to another location, such as the pulmonary artery or one of the heart chambers, it refers to the pressure in the systemic arteries, as measured, for example, in the forearm.

Cardiac Output

Total amount of blood being pumped by the heart over a particular period of time.


Thin, flexible medical tube; one use is to insert it into a blood vessel to measure blood pressure.

Clinical Trials

Medical studies of patients that evaluate the effectiveness of treatment.


Tighten; narrow.


A bluish color in the skin because of insufficient oxygen.

Diastolic Pressure

The lowest pressure to which blood pressure falls between contractions of the ventricles.


Relax; expand.


A sensation of difficulty in breathing.


Swelling due to the buildup of fluid.

Endothelial cells

The delicate lining, only one cell thick, of the organs of circulation.


Process by which inflamed tissue becomes scarred.


One complete contraction of the heart.


Describes a situation in which a body tissue is especially likely to have an exaggerated reaction to a articular situation.


Abnormally high blood pressure.


Abnormally low blood pressure.

Lung volume

The amount of air the lungs hold.

Mean blood pressure

The average blood pressure, taking account of the rise and fall that occurs with each heartbeat. It is often estimated by multiplying the diastolic pressure by two, adding the systolic pressure, and then dividing this sum by three.


The sensation of rapid heartbeats.



Pulmonary Artery

Blood vessel delivering oxygen-poor blood from the right ventricle to the lungs.

Pulmonary Hypertension

Abormally high blood pressure in the arteries of the lungs.

Smooth muscle

Muscle that performs automatic tasks, such as constricting blood vessels.


A record of the amounts of air being moved in and out of the lungs.


Fainting; temporary loss of consciousness.


Relating to a process that affects the body generally; in this instance, the way in which blood is supplied through the aorta to all body organs except the lungs.

Systolic Pressure

The highest pressure to which blood pressure rises with the contraction of the ventricles.


An agent that widens blood vessels.


One of the two pumping chambers of the heart. The right ventricle receives oxygen-poor blood from the right atrium and pumps it to the lungs through the pulmonary artery. The left ventricle recieives oxygen-rich blood from the left atrium and pumps it to the body through the aorta.


Para poder entender mas acerca de los terminos presentados en este espacio hemos preparado lo siguiente:

SINCOPE: Se define como una perdida temporal debido a una disminucion brusca del fujo sanguineo cerebral. Puede ocurrir de forma repentina, sin previo aviso, o puede estar procedido de síntomas de duracion variable.
Puede ser maligno, cuando se debe a una arritmia que pone en peligro la vida del paciente.
El paciente es advertido del desmayo inminente por una sensación de malestar, el paciente se siente confuso y puede empezar a bostezar, puede ver manchas y percibir un zumbido de oídos.
¿Cómo se produce? El mecanismo de producción en la gran mayoría de los casos de síncope es una caída brusca de la oxigenación cerebral y puede deberse a:
Una falta de oxígeno generalizada en todo el organismo.
Un fallo en la perfusión sanguínea cerebral por una alteración cardiaca, de los vasos sanguíneos y del volúmen sanguíneo (hipovolemia).

TOS: Expulsión súbita y sonora de aire procedente de los pulmones, precedida de inspiración. Es un mecanismo de defensa fundamental que sirve para eliminar agentes irritantes y secreciones de los pulmones, bronquios y tráquea, así como para evitar la aspiración de materiales extraños.

: Acumulación anormal de líquido, lo cual puede estar causado por aumento de la presión en los vasos sanguíneos , obstrucción de las venas por insuficiencia cardiáca, insificiencia renal, cirrosis hepática ,etc. Generalmente se localiza a simple vista en las extremidades del cuerpo, tobillos, piernas, manos.

MAREO: Suele significar desvanecimiento ( presincope) o vértigo.El mareo constituye un síntoma frecuente y a menudo muy molesto. Entre las sensaciones que se presentan son: aturdimiento, desvanecimiento, sensación de giro y otras que son inadecuadas e inducen a error, como confusión, visión borrosa, cefalea (dolor de cabeza) u hormigueo.

DESVANECIMIENTO: Antes de experimentar el desmayo en sí (síncope), el paciente presenta a menudo una serie de síntomas presincopales (desvanecimiento).

VERTIGO: El vértigo suele deberse a un trastorno en el sistema vestibular ( en el oído) que
se produce cuando el cerebro se enfrenta a un desequilibrio, como ocurre en el balanceo de un barco.

ESCLERODERMIA:Enfermedad autoinmune relativamente rara que afecta a los vasos sanguíneos y al tejido conectivo. Se caracteriza por degeneracion de este tejido en la piel, los pulmones y los órganos internos especialemente el esófago y los riñones, más frecuente en mujeres de mediana edad.

DISNEA: Dificultad para respirar que puede deberse a ciertas enfermedades cardíacas o respitarorias, ejercicio intenso o ansiedad.
The following glossary was prepared to help the consumer become familiar with the most common terms used in clinical trials.

ADVERSE REACTION (Adverse Event) An unwanted effect caused by the administration of drugs. Onset may be sudden or develop over time.

ADVOCACY AND SUPPORT GROUPS Organizations and groups that actively support participants and their families with valuable resources, including self-empowerment and survival tools.

APPROVED DRUGS In the U.S., the Food and Drug Administration (FDA) must approve a substance as a drug before it can be marketed.

The approval process involves several steps including pre-clinical laboratory and animal studies, clinical trials for safety and efficacy, filing of a New Drug Application by the manufacturer of the drug, FDA review of the application, and FDA approval/rejection of application.

ARM Any of the treatment groups in a randomized trial. Most randomized trials have two "arms," but some have three "arms," or even more.


1. Information gathered at the beginning of a study from which variations found in the study are measured.

2. A known value or quantity with which an unknown is compared when measured or assessed.

3. The initial time point in a clinical trial, just before a participant starts to receive the experimental treatment which is being tested. At this reference point, measurable values such as CD4 count are recorded. Safety and efficacy of a drug are often determined by monitoring changes from the baseline values.

BIAS When a point of view prevents impartial judgment on issues relating to the subject of that point of view. In clinical studies, bias is controlled by blinding and randomization.

BLIND A randomized trial is "Blind" if the participant is not told which arm of the trial he is on. A clinical trial is "Blind" if participants are unaware on whether they are in the experimental or control arm of the study; also called masked. 

CLINICAL Pertaining to or founded on observation and treatment of participants, as distinguished from theoretical or basic science.


CLINICAL INVESTIGATOR A medical researcher in charge of carrying out a clinical trial's protocol.

CLINICAL TRIAL A clinical trial is a research study to answer specific questions about vaccines or new therapies or new ways of using known treatments. Clinical trials (also called medical research and research studies) are used to determine whether new drugs or treatments are both safe and effective.

COHORT In epidemiology, a group of individuals with some characteristics in common.

COMMUNITY-BASED CLINICAL TRIAL (CBCT) A clinical trial conducted primarily through primary-care physicians rather than academic research facilities.

COMPASSIONATE USE A method of providing experimental therapeutics prior to final FDA approval for use in humans. This procedure is used with very sick individuals who have no other treatment options. Often, case-by-case approval must be obtained from the FDA for "compassionate use" of a drug or therapy.

COMPLEMENTARY AND ALTERNATIVE THERAPY Broad range of healing philosophies, approaches, and therapies that Western (conventional) medicine does not commonly use to promote well-being or treat health conditions. Examples include acupuncture, herbs, etc. Internet Address:

CONFIDENTIALITY REGARDING TRIAL PARTICIPANTS Refers to maintaining the confidentiality of trial participants including their personal identity and all personal medical information. The trial participants' consent to the use of records for data verification purposes should be obtained prior to the trial and assurance must be given that confidentiality will be maintained.

CONTRAINDICATION A specific circumstance when the use of certain treatments could be harmful.

CONTROL A control is the nature of the intervention control.

CONTROL GROUP The standard by which experimental observations are evaluated. In many clinical trials, one group of patients will be given an experimental drug or treatment, while the control group is given either a standard treatment for the illness or a placebo.

CONTROLLED TRIALS Control is a standard against which experimental observations may be evaluated. In clinical trials, one group of participants is given an experimental drug, while another group (i.e., the control group) is given either a standard treatment for the disease or a placebo.

DATA SAFETY AND MONITORING BOARD (DSMB) An independent committee, composed of community representatives and clinical research experts, that reviews data while a clinical trial is in progress to ensure that participants are not exposed to undue risk. A DSMB may recommend that a trial be stopped if there are safety concerns or if the trial objectives have been achieved.

DIAGNOSTIC TRIALS Refers to trials that are are conducted to find better tests or procedures for diagnosing a particular disease or condition. Diagnostic trials usually include people who have signs or symptoms of the disease or condition being studied.

DOSE-RANGING STUDY A clinical trial in which two or more doses of an agent (such as a drug) are tested against each other to determine which dose works best and is least harmful.

DOUBLE-BLIND STUDY A clinical trial design in which neither the participating individuals nor the study staff knows which participants are receiving the experimental drug and which are receiving a placebo (or another therapy).

Double-blind trials are thought to produce objective results, since the expectations of the doctor and the participant about the experimental drug do not affect the outcome; also called double-masked study.

DOUBLE-MASKED STUDY See Double-Blind Study.

DRUG-DRUG INTERACTION A modification of the effect of a drug when administered with another drug. The effect may be an increase or a decrease in the action of either substance, or it may be an adverse effect that is not normally associated with either drug.

DSMB See Data Safety and Monitoring Board.

EFFICACY (Of a drug or treatment) The maximum ability of a drug or treatment to produce a result regardless of dosage. A drug passes efficacy trials if it is effective at the dose tested and against the illness for which it is prescribed.

In the procedure mandated by the FDA, Phase II clinical trials gauge efficacy, and Phase III trials confirm it (See Food and Drug Administration (FDA), Phase II and III Trials).

ELIGIBILITY CRITERIA Summary criteria for participant selection; includes Inclusion and Exclusion criteria. (See Inclusion/Exclusion Criteria)

EMPIRICAL Based on experimental data, not on a theory.

ENDPOINT Overall outcome that the protocol is designed to evaluate. Common endpoints are severe toxicity, disease progression, or death.

EPIDEMIOLOGY The branch of medical science that deals with the study of incidence and distribution and control of a disease in a population.

EXCLUSION/INCLUSION CRITERIA See Inclusion/Exclusion Criteria.

EXPANDED ACCESS Refers to any of the FDA procedures, such as compassionate use, parallel track, and treatment IND that distribute experimental drugs to participants who are failing on currently available treatments for their condition and also are unable to participate in ongoing clinical trials.

EXPERIMENTAL DRUG A drug that is not FDA licensed for use in humans, or as a treatment for a particular condition.

FDA See Food and Drug Administration.

FOOD AND DRUG ADMINISTRATION (FDA) The U.S. Department of Health and Human Services agency responsible for ensuring the safety and effectiveness of all drugs, biologics, vaccines, and medical devices, including those used in the diagnosis, treatment, and prevention of HIV infection, AIDS, and AIDS-related opportunistic infections.

The FDA also works with the blood banking industry to safeguard the nation's blood supply. Internet address:

HYPOTHESIS A supposition or assumption advanced as a basis for reasoning or argument, or as a guide to experimental investigation.

INCLUSION/EXCLUSION CRITERIA The medical or social standards determining whether a person may or may not be allowed to enter a clinical trial. These criteria are based on such factors as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions.

It is important to note that inclusion and exclusion criteria are not used to reject people personally, but rather to identify appropriate participants and keep them safe.

IND See Investigational New Drug.

INFORMED CONSENT The process of learning the key facts about a clinical trial before deciding whether or not to participate. It is also a continuing process throughout the study to provide information for participants. To help someone decide whether or not to participate, the doctors and nurses involved in the trial explain the details of the study.

INFORMED CONSENT DOCUMENT A document that describes the rights of the study participants, and includes details about the study, such as its purpose, duration, required procedures, and key contacts. Risks and potential benefits are explained in the informed consent document.

The participant then decides whether or not to sign the document. Informed consent is not a contract, and the participant may withdraw from the trial at any time.


1. A committee of physicians, statisticians, researchers, community advocates, and others that ensures that a clinical trial is ethical and that the rights of study participants are protected. All clinical trials in the U.S. must be approved by an IRB before they begin.

2. Every institution that conducts or supports biomedical or behavioral research involving human participants must, by federal regulation, have an IRB that initially approves and periodically reviews the research in order to protect the rights of human participants.

INTENT TO TREAT Analysis of clinical trial results that includes all data from participants in the groups to which they were randomized ( See Randomization) even if they never received the treatment.

INTERVENTION NAME The generic name of the precise intervention being studied.

INTERVENTIONS Primary interventions being studied: types of interventions are Drug, Gene Transfer, Vaccine, Behavior, Device, or Procedure.

INVESTIGATIONAL NEW DRUG A new drug, antibiotic drug, or biological drug that is used in a clinical investigation. It also includes a biological product used in vitro for diagnostic purposes.

IRB See Institutional Review Board.

MASKED The knowledge of intervention assignment. See Blind

NATURAL HISTORY STUDY Study of the natural development of something (such as an organism or a disease) over a period of time.

NEW DRUG APPLICATION (NDA) An application submitted by the manufacturer of a drug to the FDA - after clinical trials have been completed - for a license to market the drug for a specified indication.

OFF-LABEL USE A drug prescribed for conditions other than those approved by the FDA.

OPEN-LABEL TRIAL A clinical trial in which doctors and participants know which drug or vaccine is being administered.

ORPHAN DRUGS An FDA category that refers to medications used to treat diseases and conditions that occur rarely. There is little financial incentive for the pharmaceutical industry to develop medications for these diseases or conditions. Orphan drug status, however, gives a manufacturer specific financial incentives to develop and provide such medications.

PEER REVIEW Review of a clinical trial by experts chosen by the study sponsor. These experts review the trials for scientific merit, participant safety, and ethical considerations.

PHARMACOKINETICS The processes (in a living organism) of absorption, distribution, metabolism, and excretion of a drug or vaccine.

PHASE I TRIALS Initial studies to determine the metabolism and pharmacologic actions of drugs in humans, the side effects associated with increasing doses, and to gain early evidence of effectiveness; may include healthy participants and/or patients.

PHASE II TRIALS Controlled clinical studies conducted to evaluate the effectiveness of the drug for a particular indication or indications in patients with the disease or condition under study and to determine the common short-term side effects and risks.

PHASE III TRIALS Expanded controlled and uncontrolled trials after preliminary evidence suggesting effectiveness of the drug has been obtained, and are intended to gather additional information to evaluate the overall benefit-risk relationship of the drug and provide and adequate basis for physician labeling.

PHASE IV TRIALS Post-marketing studies to delineate additional information including the drug's risks, benefits, and optimal use.

PLACEBO A placebo is an inactive pill, liquid, or powder that has no treatment value. In clinical trials, experimental treatments are often compared with placebos to assess the treatment's effectiveness. In some studies, the participants in the control group will receive a placebo instead of an active drug or treatment. No sick participant receives a placebo if there is a known beneficial treatment. (See Placebo Controlled Study).

PLACEBO CONTROLLED STUDY A method of investigation of drugs in which an inactive substance (the placebo) is given to one group of participants, while the drug being tested is given to another group. The results obtained in the two groups are then compared to see if the investigational treatment is more effective in treating the condition.

PLACEBO EFFECT A physical or emotional change, occurring after a substance is taken or administered, that is not the result of any special property of the substance. The change may be beneficial, reflecting the expectations of the participant and, often, the expectations of the person giving the substance.

PRECLINICAL Refers to the testing of experimental drugs in the test tube or in animals - the testing that occurs before trials in humans may be carried out.

PREVENTION TRIALS Refers to trials to find better ways to prevent disease in people who have never had the disease or to prevent a disease from returning. These approaches may include medicines, vitamins, vaccines, minerals, or lifestyle changes.

PROTOCOL A study plan on which all clinical trials are based. The plan is carefully designed to safeguard the health of the participants as well as answer specific research questions. A protocol describes what types of people may participate in the trial; the schedule of tests, procedures, medications, and dosages; and the length of the study.

While in a clinical trial, participants following a protocol are seen regularly by the research staff to monitor their health and to determine the safety and effectiveness of their treatment (See Inclusion/Exclusion Criteria).

QUALITY OF LIFE TRIALS (or Supportive Care trials) Refers to trials that explore ways to improve comfort and quality of life for individuals with a chronic illness.

RANDOMIZATION A method based on chance by which study participants are assigned to a treatment group. Randomization minimizes the differences among groups by equally distributing people with particular characteristics among all the trial arms.

The researchers do not know which treatment is better. From what is known at the time, any one of the treatments chosen could be of benefit to the participant (See Arm).

RANDOMIZED TRIAL A study in which participants are randomly (i.e., by chance) assigned to one of two or more treatment arms of a clinical trial. Occasionally placebos are utilized. (See Arm and Placebo).

RISK-BENEFIT RATIO The risk to individual participants versus the potential benefits. The risk/benefit ratio may differ depending on the condition being treated.

SCREENING TRIALS Refers to trials which test the best way to detect certain diseases or health conditions.

SIDE EFFECTS Any undesired actions or effects of a drug or treatment. Negative or adverse effects may include headache, nausea, hair loss, skin irritation, or other physical problems. Experimental drugs must be evaluated for both immediate and long-term side effects (See Adverse Reaction).

SINGLE-BLIND STUDY A study in which one party, either the investigator or participant, is unaware of what medication the participant is taking; also called single-masked study. (See Blind and Double-Blind Study).

SINGLE-MASKED STUDY See Single-Blind Study.

STANDARD TREATMENT A treatment currently in wide use and approved by the FDA, considered to be effective in the treatment of a specific disease or condition.

STANDARDS OF CARE Treatment regimen or medical management based on state of the art participant care.

STATISTICAL SIGNIFICANCE The probability that an event or difference occurred by chance alone. In clinical trials, the level of statistical significance depends on the number of participants studied and the observations made, as well as the magnitude of differences observed.

STUDY ENDPOINT A primary or secondary outcome used to judge the effectiveness of a treatment.

STUDY TYPE The primary investigative techniques used in an observational protocol; types are Purpose, Duration, Selection, and Timing.

TOXICITY An adverse effect produced by a drug that is detrimental to the participant's health. The level of toxicity associated with a drug will vary depending on the condition which the drug is used to treat.

TREATMENT IND IND stands for Investigational New Drug application, which is part of the process to get approval from the FDA for marketing a new prescription drug in the U.S. It makes promising new drugs available to desperately ill participants as early in the drug development process as possible.

Treatment INDs are made available to participants before general marketing begins, typically during Phase III studies. To be considered for a treatment IND a participant cannot be eligible to be in the definitive clinical trial.

Refers to trials which test new treatments, new combinations of drugs, or new approaches to surgery or radiation therapy.


Glossary of Clinical Trial Terms.  National Institutes of Health.

Reviewed by V. J. Smith, RN, BSN, MA, September 12, 2005.

Términos más comunes utilizados en Hipertensión Pulmonar

Angiograma: An x-ray of blood vessels which can be seen because the patient receives an injection of dye to outline the vessels on the x-ray.

Apnea: An apnea is a period of time during which breathing stops or is markedly reduced. There are two types of apneas, the more common obstructive sleep apnea and the less common central sleep apnea.
See the entire definition of Apnea
Arm: 1. In popular usage, the appendage that extends from the shoulder to the hand. However, the medical definition refers to the upper extremity extending from the shoulder only to the elbow, excluding the forearm, which extends from the elbow to the wrist. The arm contains one bone: the humerus. 2. In a randomized clinical trial, any of the treatment groups. Most randomized trials have two "arms," but some have three "arms," or even more.

Biochemical: Relating to biochemistry, the application of the tools and concepts of chemistry to living systems.
See the entire definition of Biochemical
Blood: The familiar red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. The blood is transported throughout the body by the circulatory system. Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys, respectively, for removal from the body.
Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".
Breathing: The process of respiration, during which air is inhaled into the lungs through the mouth or nose due to muscle contraction, and then exhaled due to muscle relaxation.
Calcium: A mineral found mainly in the hard part of bones, where it is stored. Calcium is added to bones by cells called osteoblasts and is removed from bones by cells called osteoclasts. Calcium is essential for healthy bones. It is also important for muscle contraction, heart action, nervous system maintenance, and normal blood clotting. Food sources of calcium include dairy foods, some leafy green vegetables such as broccoli and collards, canned salmon, clams, oysters, calcium-fortified foods, and tofu. According to the National Academy of Sciences, adequate intake of calcium is 1,200 milligrams a day (four glasses of milk) for men and women 51 and older, 1,000 milligrams a day for adults 19 through 50, and 1,300 milligrams a day for children 9 through 18. The upper limit for calcium intake is 2.5 grams daily.

Chest: The area of the body located between the neck and the abdomen . The chest contains the lungs , the heart and part of the aorta . The walls of the chest are supported by the dorsal vertebrae , the ribs , and the sternum .
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Chest X-ray: Commonly used to detect abnormalities in the lungs, but can also detect abnormalities in the heart, aorta, and the bones of the thoracic area. Metallic objects, such as jewelry are removed from the chest and neck areas for a chest x-ray to avoid interference with x-ray penetration and improve accuracy of the interpretation.

Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time.
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Chronic obstructive pulmonary disease : COPD. Any disorder that persistently obstructs bronchial airflow. COPD mainly involves two related diseases -- chronic bronchitis and emphysema. Both cause chronic obstruction of air flowing through the airways and in and out of the lungs. The obstruction is generally permanent and progresses (becomes worse) over time.
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Circulation: The movement of fluid in a regular or circuitous course. Although the noun "circulation" does not necessarily refer to the circulation of the blood, for all practical purposes today it does. Heart failure is an example of a problem with the circulation.
Condition: The term "condition" has a number of biomedical meanings including the following:
An unhealthy state, such as in "this is a progressive condition."
A state of fitness, such as "getting into condition."
Something that is essential to the occurrence of something else; essentially a "precondition."
As a verb: to cause a change in something so that a response that was previously associated with a certain stimulus becomes associated with another stimulus; to condition a person, as in behavioral conditioning.

COPD: Chronic obstructive pulmonary disease . Any disorder that persistently obstructs bronchial airflow. COPD mainly involves two related diseases -- chronic bronchitis and emphysema. Both cause chronic obstruction of air flowing through the airways and in and out of the lungs. The obstruction is generally permanent and progresses (becomes worse) over time.
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Cure: 1. To heal, to make well, to restore to good health. Cures are easy to claim and, all too often, difficult to confirm.
2. A time without recurrence of a disease so that the risk of recurrence is small, as in the 5-year cure rate for malignant melanoma .
3. Particularly in the past, a course of treatment. For example, take a cure at a spa.
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Diagnosis: 1 The nature of a disease ; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies . 3 The identification of any problem. The diagnosis was a plugged IV.
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Dilate: To stretch or enlarge. It comes from the Latin verb "dilatare" meaning "to enlarge or expand."
Disease: Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a fetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.

Dizziness : Painless head discomfort with many possible causes including disturbances of vision, the brain, balance (vestibular) system of the inner ear, and gastrointestinal system. Dizziness is a medically indistinct term which laypersons use to describe a variety of conditions ranging from lightheadedness, unsteadiness to vertigo.
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Embolism: The obstruction of a blood vessel by a foreign substance or a blood clot blocking the vessel. Something travels through the bloodstream, lodges in a vessel and plugs it.
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Emphysema: 1) A lung condition featuring an abnormal accumulation of air in the lung's many tiny air sacs, a tissue called alveoli. As air continues to collect in these sacs, they become enlarged, and may break, or be damaged and form scar tissue. Emphysema is strongly associated with smoking cigarettes, a practice that causes lung irritation. It can also be associated with or worsened by repeated infection of the lungs, such as is seen in chronic bronchitis. The best response to the early warning signs of emphysema is prevention: stop smoking and get immediate treatment for incipient lung infections. Curing established emphysema is not yet possible. Because patients don't have an adequate amount of space in the lungs to breathe, they gasp for breath, and may not be able to obtain enough oxygen. Those with severe emphysema usually end up using an oxygen machine to breathe. In some cases, medication may be helpful to ease symptoms or to treat infection in already-damaged lungs.
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Familial: A condition that is tends to occur more often in family members than expected by chance alone. A familial disease may be genetic (such as cystic fibrosis ) or environmental (such as tuberculosis ).
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Gene: The basic biological unit of heredity . A segment of deoxyribonucleic acid (DNA) needed to contribute to a function.
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Genetic: Having to do with genes and genetic information.

Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
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Heart ventricle: One of the two lower chambers of the heart.
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High altitude: Altitude sickness occurs at high altitude. So what is high altitude?
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High blood pressure : Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
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Hypertension: High blood pressure , defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
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Idiopathic: Of unknown cause. Any disease that is of uncertain or unknown origin may be termed idiopathic. For example, acute idiopathic polyneuritis , diffuse idiopathic skeletal hyperostosis , idiopathic pulmonary fibrosis , idiopathic scoliosis , etc.
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Left heart: The heart is composed functionally of two hearts - the right heart and the left heart. The left heart consists of the left atrium which receives oxygenated blood from the lung and the left ventricle which pumps it out to the body under high pressure.
Left ventricle: The left lower chamber of the heart that receives blood from the left atrium and pumps it out under high pressure through the aorta to the body.

Liver: An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood. The liver is the largest solid organ in the body. The liver weighs about three and a half pounds (1.6 kilograms). It measures about 8 inches (20 cm) horizontally (across) and 6.5 inches (17 cm) vertically (down) and is 4.5 inches (12 cm) thick.

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Lungs: The lungs are a pair of breathing organs located with the chest which remove carbon dioxide from and bring oxygen to the blood. There is a right and left lung.
Medication: 1. A drug or medicine. 2. The administration of a drug or medicine. (Note that "medication" does not have the dangerous double meaning of "drug.")
Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."

Nitric oxide: A compound that is toxic but which, paradoxically, plays a number of important roles in the body, including the following:
It acts as a vasodilator (blood vessel relaxant).
It therefore controls blood flow to tissues.
It regulates the binding and release of oxygen to hemoglobin .
It thereby controls the supply of oxygen to mitochondria (cell powerhouses that generate energy).
It kills parasitic organisms, virus-infected cells, and tumor cells (by inactivating respiratory chain enzymes in their mitochondria).
It stimulates the production of new mitochondria.

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Nurse: 1) A person trained, licensed, or skilled in nursing. 2) To feed an infant at the breast.
Obstruction: Blockage of a passageway. See, for example: Airway obstruction; Intestinal obstruction.

Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.
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Pelvic: Having to do with the pelvis, the lower part of the abdomen, located between the hip bones.

Primary: First or foremost in time or development. The primary teeth (the baby teeth) are those that come first. Primary may also refer to symptoms or a disease to which others are secondary.
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Pulmonary: Having to do with the lungs. (The word comes from the Latin pulmo for lung).

Pulmonary hypertension : High blood pressure in the pulmonary artery that conveys blood from the right ventricle to the lungs. The pressure in the pulmonary artery is normally low compared to that in the aorta . Pulmonary hypertension can irrevocably damage the lungs and cause failure of the right ventricle.
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Receptor: 1. In cell biology, a structure on the surface of a cell (or inside a cell) that selectively receives and binds a specific substance. There are many receptors. There is a receptor for ( insulin ; there is a receptor for low-density lipoproteins ( LDL ); etc. To take an example, the receptor for substance P, a molecule that acts as a messenger for the sensation of pain , is a unique harbor on the cell surface where substance P docks. Without this receptor, substance P cannot dock and cannot deliver its message of pain. Variant forms of nuclear hormone receptors mediate processes such as cholesterol metabolism and fatty acid production. Some hormone receptors are implicated in diseases such as diabetes and certain types of cancer. A receptor called PXR appears to jump-start the body's response to unfamiliar chemicals and may be involved in drug-drug interactions.
2. In neurology, a terminal of a sensory nerve that receives and responds to stimuli.
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Recurrent: Back again. A recurrent fever is a fever that has returned after an intermission: a recrudescent fever.
Redux: See: Dexfenfluramine.
Right heart: The heart is composed functionally of two hearts - the right heart and the left heart. The right heart consists of the right atrium which receives deoxygenated blood from the body and the right ventricle which pumps it to the lungs. The right heart is a low pressure system.

Right ventricle: The lower right chamber of the heart that receives deoxygenated blood from the right atrium and pumps it under low pressure into the lungs via the pulmonary artery.
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Scleroderma: A disease of connective tissue with the formation of scar tissue (fibrosis) in the skin and sometimes also in other organs of the body.
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Sleep : The body's rest cycle.
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Sleep apnea: The temporary stoppage of breathing during sleep , often resulting in daytime sleepiness. Apnea is a Greek word that means "want of breath."
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Smooth muscle: One of the three types of muscle tissue in the body (skeletal, smooth, cardiac). Generally forms the supporting tissue of blood vessels and hollow internal organs such as the stomach, intestine, and bladder. So named because of the absence of microscopic lines called "cross-striations" which are seen in the other two types.

Sporadic: Occurring upon occasion or in a scattered, isolated or seemingly random way.
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Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems.
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Systemic: Affecting the entire body. A systemic disease such as diabetes can affect the whole body. Systemic chemotherapy employs drugs that travel through the bloodstream and reach and affect cells all over the body.
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Therapy: The treatment of disease .
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Transforming growth factor: (TGF) One of several proteins secreted by transformed cells that can stimulate the growth of normal cells. Transforming growth factor alpha (TGF alpha or TGF-A) binds the epidermal growth factor receptor (EGFR) and stimulates the growth of endothelial cells (cells that line the inside of blood vessels). Transforming growth factor beta (TGF-beta or TGF-B) is found in hematopoietic (blood-forming) tissue and initiates a signaling pathway that suppresses the early development of cancer cells.
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Ventricle: A chamber of an organ. For example, the four connected cavities (hollow spaces) in the central portion of the brain and the lower two chambers of the heart are called ventricles.

X-ray: 1. High-energy radiation with waves shorter than those of visible light. X-rays possess the properties of penetrating most substances (to varying extents), of acting on a photographic film or plate (permitting radiography), and of causing a fluorescent screen to give off light (permitting fluoroscopy). In low doses X-rays are used for making images that help to diagnose disease, and in high doses to treat cancer . Formerly called a Roentgen ray. 2. An image obtained by means of X-rays.
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