Pulmonary hypertension (PH) is defined hemodynamically as a mean pulmonary artery pressure (mPAP) >20 mmHg at rest on right heart catheterization, classified into 5 WHO groups based on etiology. [1-2] The most common causes are left heart disease (Group 2) and chronic lung disease (Group 3), while pulmonary arterial hypertension (Group 1) is rare (~10.6 per million adults in the US) but carries significant morbidity and mortality. [1][3] Untreated PAH progresses to right heart failure and death, with 5-year survival improving from 34% (1991) to >60% (2015) with modern therapies. [1]
1. History
- Key HPI: Progressive exertional dyspnea (most common presenting symptom, 60% at onset, 98% at diagnosis), fatigue, exercise intolerance, chest pain, palpitations, lightheadedness, presyncope/syncope [1][4-5]
- Timing: Insidious onset; diagnosis often delayed >2 years from symptom onset (21% of patients in the REVEAL registry) [1]
- Progression: Symptoms initially exertional → progress to minimal exertion or rest with advanced disease [1]
- Associated symptoms: Lower extremity edema, abdominal distension (ascites), weight gain from fluid retention, anorexia [4][6]
- Important negatives: Orthopnea and PND (more suggestive of left heart disease), productive cough, wheezing (lung disease), prior DVT/PE (CTEPH) [2][6]
- Exposure history: Methamphetamine/cocaine use, anorexigens (fenfluramine, aminorex), dasatinib, prior chemotherapy [7-8]
2. Alarm Features
- Syncope or presyncope on exertion — indicates severely limited cardiac output [1-2]
- Rapid symptom progression with severely reduced exercise capacity [2]
- Signs of acute right heart failure: Hypotension, tachycardia, declining urine output, rising lactate, peripheral cyanosis [2]
- Hemodynamic instability in a known PH patient — risk of PH crisis with cardiovascular collapse [9-10]
- Abrupt discontinuation of prostacyclin therapy — can cause fatal rebound PH [1]
- New arrhythmia (atrial flutter/fibrillation) — poorly tolerated in PH patients [2]
3. Medications
- PAH-targeted therapies (3 classes approved for Group 1 PH): [8][11]
- PDE5 inhibitors: sildenafil, tadalafil
- Endothelin receptor antagonists (ERAs): bosentan, ambrisentan, macitentan
- Prostacyclin pathway agonists: epoprostenol (IV), treprostinil (IV/SC/inhaled/oral), iloprost (inhaled), selexipag (oral)
- Soluble guanylate cyclase stimulator: riociguat
- Calcium channel blockers: Only for vasoreactivity-positive idiopathic/heritable PAH; contraindicated without vasoreactivity testing [1-2]
- Contraindicated combinations: Riociguat + PDE5 inhibitors (similar mechanism) [1-2]
- ERAs are teratogenic: Require monthly pregnancy testing [1]
- Medication contributors to PH: Methamphetamines, dasatinib, fenfluramine, interferon-α/β, certain chemotherapy agents [7]
- Caution: PDE5 inhibitors shown detrimental in Group 2 PH post-valvular surgery and increase painful crises in sickle cell PH (Group 5) [8]
- Supportive medications: Diuretics (volume management), supplemental O₂, anticoagulation (selected patients) [12-13]
The following table summarizes FDA-approved PAH medications, their mechanisms, adverse effects, and key safety notes:
4. Diet
- Sodium restriction: Essential for fluid management, particularly in patients with right heart failure and volume overload [2]
- Fluid restriction: May be necessary in decompensated right heart failure
- Iron supplementation: Consider in patients with iron deficiency (common in PAH)
- Avoid excessive caffeine and alcohol
- Pregnancy avoidance: Strongly recommended — pregnancy carries extremely high mortality risk in PAH [1]
5. Review of Systems
- Cardiovascular: Chest pain, palpitations, syncope, lower extremity edema, exercise intolerance
- Pulmonary: Dyspnea (exertional → rest), cough, hemoptysis (rare; from bronchial artery collaterals or pulmonary artery dilation)
- GI: Abdominal distension, early satiety, anorexia (hepatic congestion, ascites, bowel wall edema) [10]
- Musculoskeletal: Fatigue, weakness
- Rheumatologic: Raynaud phenomenon, skin changes, joint symptoms (connective tissue disease screening) [4]
- Neurologic: Lightheadedness, presyncope, syncope
6. Collateral History and Family History
- Family history of PAH: Heritable PAH accounts for a subset of Group 1; BMPR2 mutations represent ~80% of identified mutations [8]
- Connective tissue disease: Especially systemic sclerosis (highest PAH risk among CTDs) [4][14]
- HIV status, hepatitis B/C, liver disease (portal hypertension) [4][7]
- History of PE/DVT or risk factors for CTEPH (splenectomy, permanent intravascular devices, inflammatory bowel disease, myeloproliferative disorders) [2]
- Drug use history: Methamphetamine, cocaine, prior anorexigen use [5][7]
- Social context: Functional limitations, WHO functional class assessment, psychosocial support needs
7. Risk Factors
- Connective tissue disease (systemic sclerosis most common) [4][14]
- HIV infection [4][7]
- Portal hypertension/liver disease [6-7]
- Congenital heart disease (repaired or unrepaired shunts) [2]
- Methamphetamine/stimulant use [7-8]
- Prior pulmonary embolism (CTEPH risk) [2-3]
- Chronic lung disease (COPD, ILD, OSA/obesity hypoventilation) [2]
- Left heart disease (HFpEF, HFrEF, valvular disease — most common cause of PH overall) [2][8]
- Schistosomiasis (most common cause of PAH worldwide) [8]
- Female sex and younger age for idiopathic PAH [1-2]
- Sickle cell disease, myeloproliferative disorders [15]
8. Differential Diagnosis
- Left heart failure (HFpEF/HFrEF) — most common cause of PH; distinguished by elevated PAWP >15 mmHg on RHC [1-2]
- Chronic lung disease (COPD, ILD) — abnormal PFTs, parenchymal changes on CT [2]
- Chronic thromboembolic PH (CTEPH) — must be excluded with V/Q scan before diagnosing PAH; mismatched perfusion defects are pathognomonic [2-3]
- Pulmonary embolism (acute) — acute onset, CT angiography diagnostic
- Deconditioning/obesity — diagnosis of exclusion
- Valvular heart disease (mitral stenosis, aortic stenosis) — echocardiographic evaluation [2]
- Obstructive sleep apnea — uncommon cause of PH unless coexisting conditions present [2]
- Pulmonary veno-occlusive disease — may develop pulmonary edema with PAH-targeted therapy; CT shows septal lines, centrilobular ground-glass opacities [7-8]
- Sarcoidosis, fibrosing mediastinitis (Group 5) [2]
9. Past Medical History
- Prior episodes of dyspnea, syncope, or right heart failure
- Known connective tissue disease, HIV, liver disease, congenital heart disease
- History of PE/DVT or hypercoagulable states
- Chronic lung disease (COPD, ILD, OSA)
- Left heart disease, valvular disease, atrial fibrillation
- Prior cardiac surgery
- Thyroid disease (associated with PAH)
- Medication history including prior PAH-targeted therapies and response
10. Physical Exam
- Vital signs: Tachycardia, hypotension (late/ominous), low SpO₂ [5]
- Cardiac: Loud P2 (93% of PAH patients), right-sided S3/S4, RV heave, holosystolic murmur of tricuspid regurgitation, diastolic murmur of pulmonic insufficiency [1][4-6]
- JVP: Elevated with prominent A waves (RV stiffness) and V waves (TR); Kussmaul sign [6]
- Abdomen: Hepatomegaly, hepatojugular reflux, ascites [5]
- Extremities: Lower extremity edema, prolonged capillary refill, peripheral cyanosis [5]
- Skin: Sclerodactyly, telangiectasias, digital ulcers (systemic sclerosis); spider angiomata (portal hypertension) [4][6]
- Clubbing: Suggests congenital heart disease or pulmonary veno-occlusive disease
11. Lab Studies
- Initial labs: [1]
- CBC (anemia, polycythemia)
- BMP (renal function, electrolytes)
- LFTs (hepatic congestion, portal hypertension)
- TSH (thyroid dysfunction associated with PAH)
- BNP/NT-proBNP — elevated with RV dysfunction; prognostic marker (HR 1.84 for death per unit increase) [1]
- ANA (connective tissue disease screening)
- Additional when PAH confirmed: [1]
- Autoimmune serologies (anti-Scl-70, anti-centromere, anti-dsDNA)
- HIV antibody
- Hepatitis B/C panel
- Monitoring: Lactate (tissue perfusion), troponin (RV ischemia), central venous O₂ saturation [2]
- Expected abnormalities: Elevated NT-proBNP, elevated transaminases (hepatic congestion), elevated creatinine (cardiorenal syndrome)
12. Imaging
- Chest X-ray (first-line): Enlarged central pulmonary arteries, RV/RA enlargement, pruning of peripheral vessels; high sensitivity/specificity for moderate-severe PH [5][16]
- Transthoracic echocardiography (recommended initial test for suspected PH): Estimates sPAP via TRV, assesses RV size/function, TAPSE, septal flattening, IVC dilation [2][5]
- Sensitivity ~85%, specificity ~70-74% for PH [1]
- Cannot confirm diagnosis — RHC required [1-2]
- V/Q scan: Required to exclude CTEPH; mismatched perfusion defects diagnostic [2-3]
- CT chest: Parenchymal lung disease assessment; PA diameter >29 mm suggestive of PH; CT pulmonary angiography for CTEPH workup [2]
- Cardiac MRI: Gold standard for RV size/function assessment (not always available acutely)
- When imaging is unnecessary: Mild PH with clear left heart disease or lung disease etiology may not require further imaging beyond echo [5]
13. Special Tests
- Right heart catheterization — gold standard for diagnosis and classification: [1]
- PAH defined: mPAP >20 mmHg, PAWP ≤15 mmHg, PVR ≥3 Wood units [1]
- Low complication rate: serious complications 1.1%, death 0.055% [1]
- Acute vasoreactivity testing (during RHC): Inhaled nitric oxide challenge; positive response → calcium channel blocker candidacy [1]
- 6-minute walk test: Functional capacity assessment and treatment monitoring [12]
- Pulmonary function tests with DLCO: Normal spirometry with low DLCO (78% of PAH patients) suggests pulmonary vascular disease [1-2]
- Cardiopulmonary exercise testing (CPET): High VE/VCO₂ slope, low PETCO₂ in PAH [2]
- Risk stratification tools: ESC/ERS risk assessment, REVEAL score [4][12]
14. ECG
- Typical findings (abnormal in ~87% of PAH patients): [1]
- Right axis deviation (79%)
- RV hypertrophy (87%) — tall R wave in V1, R/S ratio >1 in V1
- RV strain pattern (74%) — ST depression/T-wave inversions in right precordial leads
- Right bundle branch block (complete or incomplete)
- P-pulmonale — peaked P waves in lead II (right atrial enlargement) [16]
- Diagnostic accuracy: Heart rate + RV strain pattern had sensitivity 79%, specificity 60% for PAH on RHC [1]
- Normal ECG does not exclude PH (13% of PAH patients had normal ECG) [1]
- Arrhythmias: Atrial flutter/fibrillation — poorly tolerated and may precipitate decompensation
15. Assessment
- WHO Classification (5 groups): [2]
- Group 1: PAH (idiopathic, heritable, drug/toxin, CTD, HIV, portal HTN, CHD)
- Group 2: Left heart disease (most common overall)
- Group 3: Lung disease/hypoxia
- Group 4: Pulmonary artery obstructions (CTEPH)
- Group 5: Unclear/multifactorial mechanisms
- Severity stratification by WHO Functional Class (I–IV) and risk assessment tools [2][12]
- Typical presentation: Young-to-middle-aged woman with progressive exertional dyspnea, fatigue, and loud P2 (idiopathic PAH); elderly patient with comorbid heart/lung disease (Groups 2/3) [1-2]
- Complications: Right heart failure, arrhythmias, hemoptysis, pulmonary artery aneurysm/dissection (rare), renal dysfunction, hepatic congestion [2][10]
16. Treatment Plan
The following treatment algorithm from Hassoun (NEJM 2021) illustrates the risk-stratified approach to PAH management:
- Initial stabilization (ED/ICU): [2][17-18]
- Supplemental O₂ to maintain SpO₂ >90%
- Avoid intubation if possible — positive pressure ventilation worsens RV failure
- Avoid aggressive fluid resuscitation — most decompensated PH patients are volume overloaded; diuresis preferred
- Vasopressors (norepinephrine preferred) for hypotension rather than fluids
- Inotropes: dobutamine or milrinone for low cardiac output
- Inhaled pulmonary vasodilators (iNO, inhaled epoprostenol) for acute RV failure [9][13]
- Do not discontinue home PAH medications — rebound PH can be fatal [1][17]
- Chronic PAH management: [1-2]
- Low/intermediate risk: Initial oral combination therapy (ERA + PDE5i; e.g., ambrisentan + tadalafil or macitentan + tadalafil)
- High risk: Triple combination including IV/SC prostacyclin analogue
- Vasoreactive patients: High-dose calcium channel blockers with close follow-up at 3–4 months including repeat RHC
- Reassess risk every 3–6 months; escalate therapy if low-risk status not achieved
- Group-specific treatment: [2-3][8]
- Group 2: Treat underlying heart disease; PAH-targeted therapies generally not beneficial
- Group 3: Treat underlying lung disease; inhaled treprostinil approved for ILD-associated PH
- Group 4 (CTEPH): Pulmonary endarterectomy (surgical, treatment of choice); riociguat for inoperable cases; balloon pulmonary angioplasty
- Group 5: Treat underlying condition
- Lung transplantation: Consider for patients failing maximal medical therapy [2]
17. Disposition
- Admit (ICU): [2][10]
- Acute right heart failure with hemodynamic instability
- Syncope or presyncope
- New-onset arrhythmia with hemodynamic compromise
- Hypotension, rising lactate, end-organ dysfunction
- Interruption of prostacyclin therapy
- Newly diagnosed severe PH with high-risk features
- Admit (telemetry/ward):
- Decompensated right heart failure requiring IV diuresis
- New diagnosis of PH requiring workup
- Significant hypoxemia
- Discharge considerations:
- Stable known PH patient with mild exacerbation responsive to oral diuretics
- No syncope, hemodynamic stability, adequate oxygenation
- Reliable follow-up with PH specialist
- Specialist consultation triggers: [3][5]
- All patients with suspected or confirmed PAH or CTEPH → referral to PH center
- Early involvement of PH specialist for any decompensated PH patient [2]
- Consider transfer to tertiary center with PA catheter capability, inhaled vasodilators, and ECMO [17]
18. Follow Up / Return Precautions
- Follow-up timing: PH specialist within 1–2 weeks if newly diagnosed; every 3–6 months for established patients on therapy with comprehensive reassessment (echo, 6MWT, NT-proBNP, functional class) [1-2]
- Return immediately for:
- Worsening shortness of breath at rest
- Syncope or near-syncope
- New or worsening leg swelling, abdominal distension
- Chest pain
- Any interruption of continuous prostacyclin infusion
- Fever or signs of line infection (for patients on IV/SC prostacyclin)
- Patient counseling:
- Never abruptly stop PAH medications — especially prostacyclin analogues [1]
- Avoid pregnancy (teratogenic medications; high maternal mortality) [1]
- Daily weights, sodium restriction, adherence to diuretics
- Supervised exercise rehabilitation (improves functional capacity)
- Vaccinations (influenza, pneumococcal, COVID-19) [19]
- Avoid high altitude and excessive physical exertion
- Expected course: PAH is a chronic, progressive disease; current therapies improve symptoms and survival but are not curative [11]
References
1. Diagnosis and Treatment of Pulmonary Arterial Hypertension: A Review. — Ruopp NF, Cockrill BA. The Journal of the American Medical Association. 2022.
2. 2022 ESC/ERS Guidelines for the Diagnosis and Treatment of Pulmonary Hypertension. — Humbert M, Kovacs G, Hoeper MM, et al. The European Respiratory Journal. 2023.
3. Pulmonary Hypertension: A Brief Guide for Clinicians. — Mandras SA, Mehta HS, Vaidya A. Mayo Clinic Proceedings. 2020.
4. Pulmonary Arterial Hypertension. — Hassoun PM. The New England Journal of Medicine. 2021.
5. Pulmonary Hypertension. — Latimer K, Layne M, Payne M. American Family Physician. 2024.
6. Management of Pulmonary Arterial hypertension. — McLaughlin VV, Shah SJ, Souza R, Humbert M. Journal of the American College of Cardiology. 2015.
7. ACR Appropriateness Criteria® Suspected Pulmonary Hypertension: 2022 Update. — Expert Panel on Thoracic Imaging, Sirajuddin A, Mirmomen SM, et al. Journal of the American College of Radiology : JACR. 2022.
8. Evaluation and Management of Pulmonary Hypertension in Noncardiac Surgery: A Scientific Statement From the American Heart Association. — Rajagopal S, Ruetzler K, Ghadimi K, et al. Circulation. 2023.
9. Intensive care management of right ventricular failure and pulmonary hypertension crises. — Coleman RD, Chartan CA, Mourani PM. Pediatric Pulmonology. 2021.
10. Management of Acutely Decompensated Pulmonary Hypertension. — Savale L, Kularatne M, Roche A, et al. Seminars in Respiratory and Critical Care Medicine. 2023.
11. Treatment of Pulmonary Arterial Hypertension: Recent Progress and a Look to the Future. — Humbert M, Sitbon O, Guignabert C, et al. The Lancet. Respiratory Medicine. 2023.
12. Phosphodiesterase Type 5 Inhibitor Plus Endothelin Receptor Antagonist Compared to Either Alone for Group 1 Pulmonary Arterial Hypertension. — Oba Y, Maduke T, Fakhouri EW, Goite Y. The Cochrane Database of Systematic Reviews. 2025.
13. Right Ventricular Failure. — Houston BA, Brittain EL, Tedford RJ. The New England Journal of Medicine. 2023.
14. Clinical Characteristics and Transplant-Free Survival Across the Spectrum of Pulmonary Vascular Disease. — Hemnes AR, Leopold JA, Radeva MK, et al. Journal of the American College of Cardiology. 2022.
15. Guidelines for the Echocardiographic Assessment of the Right Heart in Adults and Special Considerations in Pulmonary Hypertension: Recommendations From the American Society of Echocardiography. — Mukherjee M, Rudski LG, Addetia K, et al. Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography. 2025.
16. Doppler Trans-Thoracic Echocardiography for Detection of Pulmonary Hypertension in Adults. — Tsujimoto Y, Kumasawa J, Shimizu S, et al. The Cochrane Database of Systematic Reviews. 2022.
17. Pulmonary Hypertension and Right Ventricular Failure in Emergency Medicine. — Wilcox SR, Kabrhel C, Channick RN. Annals of Emergency Medicine. 2015.
18. Right Heart Failure: A Narrative Review for Emergency Clinicians. — Kostura M, Smalley C, Koyfman A, Long B. The American Journal of Emergency Medicine. 2022.
19. Updated Treatment Algorithm of Pulmonary Arterial Hypertension. — Galiè N, Corris PA, Frost A, et al. Journal of the American College of Cardiology. 2013.