What are the other Names for this Condition? (Also known as/Synonyms)

• IPAH (Idiopathic Pulmonary Arterial Hypertension)

What is Idiopathic Pulmonary Arterial Hypertension? (Definition/Background Information)

• Pulmonary arterial hypertension (PAH) is a specific type of hypertension that is caused by increased blood pressure within the pulmonary (lung) arteries. When there is no identifiable cause for PAH, it is termed Idiopathic Pulmonary Arterial Hypertension (IPAH)
• In general, pulmonary hypertension (PH) is a disorder characterized by very high blood pressure (above normal) in the lungs due to a variety of causes. It should not be confused with systemic hypertension, otherwise known as ‘high blood pressure’
• The World Health Organization (WHO) has clinically classified pulmonary hypertension according to certain groups. Idiopathic Pulmonary Arterial Hypertension forms part of WHO group 1 (sub group 1.1)
• The signs and symptoms of Idiopathic Pulmonary Arterial Hypertension may include shortness of breath, chest pain, fatigue, and dizziness. A diagnosis of the condition may involve procedures such as right-heart catheterization and acute vasodilator challenge
• Following a diagnosis, the treatment measures for Idiopathic Pulmonary Arterial Hypertension may involve the use of medications, such as calcium channel blockers, and bringing about certain lifestyle modifications, among other measures
• The prognosis of Idiopathic Pulmonary Arterial Hypertension may be improved if it is diagnosed promptly and treated appropriately. However, the overall prognosis depends on several factors and may vary on a case-to-case basis

Who gets Idiopathic Pulmonary Arterial Hypertension? (Age and Sex Distribution)

• Idiopathic Pulmonary Arterial Hypertension (IPAH) can occur at any age, but the condition is mainly observed in younger adults
• It is estimated that about 5-15 individuals per million receive a diagnosis of IPAH, making it rare among the general population
• The condition is noted in both male and female genders; but, women are affected almost 3 times more than men
• IPAH is observed in all racial and ethnic groups, although Caucasians show a higher prevalence of the condition (much more than African Americans, Hispanics, and Asians)

What are the Risk Factors for Idiopathic Pulmonary Arterial Hypertension? (Predisposing Factors)

• Idiopathic Pulmonary Arterial Hypertension occurs without a clear cause, and therefore, no clearly defined risk factors have been identified

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Idiopathic Pulmonary Arterial Hypertension? (Etiology)

The exact cause and development of Idiopathic Pulmonary Arterial Hypertension is presently unknown.

What are the Signs and Symptoms of Idiopathic Pulmonary Arterial Hypertension?

The signs and symptoms of Idiopathic Pulmonary Arterial Hypertension depend on a set of several factors that include the age and overall health status of the individual. The common signs and symptoms exhibited by individuals with IPAH are similar to most individuals with pulmonary hypertension. These include:

• Progressive shortness of breath, especially while exercising, is the most common symptom
• Fatigue (frequent tiredness)
• Chest pain
• Dizziness and fainting
• Swelling of the ankles/legs
• Palpitations
• Bluish lips and skin, observed during the later stages
• Irregular heartbeat (arrhythmias)
• Fluid in the abdomen (ascites)

How is Idiopathic Pulmonary Arterial Hypertension Diagnosed?

To diagnose Idiopathic Pulmonary Arterial Hypertension (IPAH), a diagnosis of pulmonary hypertension (PH) must first be established. This involves certain preliminary diagnostic procedures. Depending on the results of these tests, confirmation will be made with a right-heart catheterization.

After a diagnosis of pulmonary hypertension is made, the healthcare provider should rule out any and all other causes of PH before diagnosing IPAH. Thus, the diagnosis of IPAH is a diagnosis of exclusion.

The preliminary procedures may include:

• A complete physical examination of the patient 
• A thorough checking of the patient’s medical history and a detailed checking of the family history of the patient
• Blood tests:
  • Blood tests help rule out other diseases, such as HIV infection, liver disease, rheumatoid or connective tissue disease, and thyroid disease
  • They also help in checking the blood oxygen levels
  • The measurement of brain natriuretic peptide (BNP) can be used to assess the strain on one’s heart
• Chest X-ray: Chest X-rays can reveal structural signs of pulmonary hypertension by identifying changes in the pulmonary arteries or enlargement of the right side of the heart
• Electrocardiogram (ECG): An electrocardiogram checks the electrical impulses of the heart. There are certain identifiable patterns on an ECG that may indicate pulmonary hypertension. However, ECG is not specific enough to diagnose the condition by itself, so a combination of tests may be recommended by the healthcare provider
• Echocardiogram: In this procedure, a sonogram of the heart is taken and used to measure overall functioning as well as measure the pressure within the chambers of the right heart. An echocardiogram is also often times used to monitor a patient’s condition after diagnosis and during treatment
• Pulmonary function tests: These tests help measure the quality of breathing and check the functioning of the lungs (such as how much air is breathed in and out, as well as the quality of oxygen exchange)
• Exercise tolerance test (six-minute walk test): This helps to measure the patient’s ability to exercise
• Nuclear scan (ventilation/perfusion scan or V/Q scan): This tool helps identify any new or chronic blood clots in the vessels of the lungs that could be causing pulmonary hypertension

The gold standard for pulmonary hypertension diagnosis and management is right-heart catheterization and acute vasodilator challenge.

• Right-heart catheterization:
  • If pulmonary hypertension is suspected based off preliminary tests and procedures, a right-heart catheterization test is ordered to help confirm the diagnosis
  • This test can accurately quantify right-heart pressures (measure the pressure within the chambers of the right heart), especially the pressure inside the pulmonary arteries
  • During this procedure, a very small catheter is inserted into a large vein (either within the patient’s groin or neck) and passed into the patient’s heart and vasculature to measure the internal blood pressures 
• Vasodilator study (acute vasodilator challenge):
  • While this test is not used to necessarily “diagnose” pulmonary hypertension, it is used to evaluate the patient for possible therapeutic management
  • Like right-heart catheterization, a catheter is placed within the pulmonary artery to test for vasodilation (or relaxation) in response to a class of medications called calcium channel blockers (CCBs)
  • The response and dosing of CCBs can be evaluated with this procedure

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Idiopathic Pulmonary Arterial Hypertension?

Following are the possible complications that may arise due to Idiopathic Pulmonary Arterial Hypertension:

• Right-sided heart failure with hepatic congestion (due to deposition of stones in the liver)
• Pedal edema: Swelling of the leg or ankle
• Pleural effusions: Building-up of excess fluid around the lungs
• Worsening dyspnea (shortness of breath) upon exertion

How is Idiopathic Pulmonary Arterial Hypertension Treated?

The treatment of Idiopathic Pulmonary Arterial Hypertension (IPAH) depends on a set of several factors that includes the severity of the signs and symptoms, age of the individual, and overall health of the individual.

IPAH is a rare condition that is best treated at a medical center with appropriate expertise. Several medical treatments are highlighted below:

• Conventional medical therapies:
  • Calcium channel blockers (CCBs): These are a group of medications that help vasodilate (or relax) the arteries. However, CCBs are only appropriate for patients demonstrating a favorable response to the vasodilator study
  • Inotropic agents: These are medications that assist in the pumping of the heart 
  • Diuretics, salt limitation, and weight monitoring may be recommended, to limit excess strain on the heart
  • Supplemental oxygen may help an individual meet the ‘oxygen needs’ for normal daily activities
  • Blood thinners: These medications help prevent blood clots, especially in the lung blood vessels
• Oral, inhaled, subcutaneous, or intravenous treatment options:
  • Endothelin receptor antagonists (ERAs) help in preventing pulmonary blood vessels from narrowing which helps keep the pressures towards normal levels
  • Phosphodiesterase inhibitors (PDE 5 Inhibitors), prostacyclin analogues, and soluble guanylate cyclase (sGC) stimulators, all aid in allowing vessels of the lungs to vasodilate (or relax)
• Additional treatment options may include:
  • Lifestyle modifications, such as nutrition, exercise, avoiding tobacco, and limiting alcohol consumption, are beneficial
  • Judicious exercising may be effective in limiting deconditioning (by building stamina), improving the quality of life, and exercising capacities. Isometric exercises, such as heavy weightlifting, should be avoided
  • Lung transplantation may be required with advanced forms of the disorder

How can Idiopathic Pulmonary Arterial Hypertension be Prevented?

Currently, there are no preventive measures available for Idiopathic Pulmonary Arterial Hypertension since the cause of the condition is unknown. However, an early and effective treatment is critical and imperative.

• Avoidance of recreational drugs, various toxic agents, and inappropriate weight loss drugs is important
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Idiopathic Pulmonary Arterial Hypertension? (Outcomes/Resolutions)

The prognosis of Idiopathic Pulmonary Arterial Hypertension differs from one individual to another, depending on the severity of the condition/pulmonary hypertension. The disorder has no cure, but an earlier and focused treatment can help improve outcomes.

• Individuals with advanced heart disease, a suboptimal 6-minute walk test (exercise tolerance test to measure one’s ability to exercise without significant signs and symptoms), and with conditions, such as advanced liver disease and connective tissue disease, have poor prognosis
• Pulmonary hypertension is a negative prognostic sign in many medical conditions, meaning that the presence of PH makes the overall health outcomes worse. For example, in individuals who have COPD or heart failure, the development of PH worsens the overall outcomes

Additional and Relevant Useful Information for Idiopathic Pulmonary Arterial Hypertension:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/diseases-conditions/pulmonary-hypertension-ph/