Idiopathic/heritable pulmonary arterial hypertension

What it is

From: Orphanet

A form of pulmonary arterial hypertension (PAH) characterized by elevated pulmonary arterial resistance leading to right heart failure; it is progressive and potentially fatal. The majority cases have an identifiable genetic cause, but a significant proportion are idiopathic.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Pulmonary arterial hypertension · Very frequent (99-80%)

Pulmonary hypertension is defined mean pulmonary artery pressure of 25mmHg or more and pulmonary capillary wedge pressure of 15mmHg or less when measured by right heart catheterisation at rest and in a supine position.

Abnormality of cardiovascular system physiology · Frequent (79-30%)

Abnormal functionality of the cardiovascular system.

Dyspnea · Frequent (79-30%)

Difficult or labored breathing. Dyspnea is a subjective feeling only the patient can rate, e.g., on a Borg scale.

Chest pain · Occasional (29-5%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) localized to the chest.

Elevated jugular venous pressure · Occasional (29-5%)

Increased jugular venous pressure.

Fatigue · Occasional (29-5%)

A subjective feeling of tiredness characterized by a lack of energy and motivation.

Heart murmur · Occasional (29-5%)

An extra or unusual sound heard during a heartbeat caused vibrations resulting from the flow of blood through the heart.

Hepatomegaly · Occasional (29-5%)

Abnormally increased size of the liver.

Palpitations · Occasional (29-5%)

A sensation that the heart is pounding or racing, which is a non-specific sign but may be a manifestation of arrhythmia.

Right ventricular dilatation · Occasional (29-5%)

Enlargement of the chamber of the right ventricle, which can be defined echocardiographically as a right ventricular to left ventricular ratio greater than 1:1.

Syncope · Occasional (29-5%)

A transient loss of consciousness (i.e., characterized by a rapid onset, a short duration, and a spontaneous and complete recovery) due to cerebral hypoperfusion.

Tricuspid regurgitation · Occasional (29-5%)

Failure of the tricuspid valve to close sufficiently upon contraction of the right ventricle, causing blood to regurgitate (flow backward) into the right atrium.

Pedal edema · Very rare (<4-1%)

An abnormal accumulation of excess fluid in the lower extremity resulting in swelling of the feet and extending upward to the lower leg.

When it may begin

From: Orphanet

All ages

Inheritance in the source

From: Orphanet

Autosomal dominant; Autosomal recessive; Not applicable

Frequency and the population described

From: Orphanet

Annual incidence: 1-9 / 1 000 000; United States; Value and class. Point prevalence: 1-9 / 1 000 000; France; Value and class. Annual incidence: 1-9 / 1 000 000; France; Value and class. Point prevalence: 1-9 / 100 000; Czech Republic; Value and class.

Which doctor should you see?

The suggested department for discussing Idiopathic/heritable pulmonary arterial hypertension is Pulmonology, with a pulmonologist / chest physician as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• What is the likely explanation for the breathing symptoms?
• Would a breathing test or another investigation change management?
• If symptoms worsen, what written action plan should be followed?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Idiopathic/heritable pulmonary arterial hypertension. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.