The diagnosis of the disorder is often delayed due to nonspecific symptoms and signs, frequently reflecting the underlying etiology. Common presenting features are exertional dyspnea, lethargy, fatigue, exertional syncope and chest pain, peripheral edema, anorexia and right upper quadrant pain [2] [3] [4]. Uncommon symptoms include cough, hemoptysis and hoarseness.

The diagnosis of pulmonary hypertension should be suspected in patients with progressive exertional dyspnea, angina or syncope on exertion and a coexisting possible cause of the condition. Electrocardiography (ECG), laboratory studies (complete blood count (CBC), liver function tests, HIV serology, prothrombin time (PT), and activated partial thromboplastin time (aPTT)), arterial blood gas measurements and X-rays of the chest should be obtained. Echocardiography with Doppler flow studies is the most useful noninvasive method and can be employed to estimate the pulmonary artery pressure and ventricular function [5] [6]. Depending on the etiology, further evaluation may include pulmonary function testing, high-resolution computed tomography of the chest, polysomnography, ventilation-perfusion lung scanning and right cardiac catheterization. The diagnosis of most forms of pulmonary hypertension requires right heart catheterization and is confirmed when the mean pulmonary artery pressure is greater than 25 mmHg at rest [1].

Pulmonary hypertension is characterized by a mean pulmonary arterial pressure exceeding 25 mm Hg at rest or 30 mm Hg during exercise [1]. The World Health Organization (WHO) classified pulmonary hypertension into five main groups based upon etiology and disease mechanisms:

Pulmonary arterial hypertension (PAH)

• Idiopathic PAH
• Heritable (BMPR2/ALK1, endoglin, SMAD9, CAV1, KCNK3/Unknown)
• Drug- and toxin-induced
• Associated with Connective tissue diseases/HIV infection/Portal hypertension/Congenital heart diseases/Schistosomiasis
• Pulmonary veno-occlusive disease (PVOD) and/or pulmonary capillary hemangiomatosis (PCH)
• Persistent pulmonary hypertension of the newborn (PPHN)

Pulmonary hypertension owing to left heart disease

• Left ventricular systolic dysfunction
• Left ventricular diastolic dysfunction
• Valvular heart disease
• Congenital/acquired left heart inflow/outflow tract obstruction and congenital cardiomyopathies

Pulmonary hypertension owing to lung diseases and/or hypoxia

• Chronic obstructive pulmonary disease
• Interstitial lung disease
• Other pulmonary diseases with mixed restrictive and obstructive pattern
• Sleep-disordered breathing
• Alveolar hypoventilation disorders
• Chronic exposure to high altitude
• Developmental abnormalities

Chronic thromboembolic pulmonary hypertension (CTEPH)

Pulmonary hypertension with unclear multifactorial mechanisms

• Hematologic disorders: Chronic hemolytic anemia, myeloproliferative disorders, splenectomy
• Systemic disorders: Sarcoidosis, pulmonary Langerhans cell histiocytosis: lymphangioleiomyomatosis, neurofibromatosis, vasculitis
• Metabolic disorders: Glycogen storage disease, Gaucher disease, thyroid disorders
• Others: Tumoral obstruction, fibrosing mediastinitis, chronic renal failure, segmental pulmonary hypertension

Definition

Pulmonary hypertension is a rise of blood pressure and resistance in the lung vessels.

Cause

Pulmonary hypertension may be without any cause or with some associated factors like cirrhosis of the liver, appetite suppressants, HIV infection, alpha adrenergic stimulants like amphetamine and cocaine. It may also be due to some underlying diseases like left side heart diseases such as valvular abnormalities, myocardial diseases, and compression of pulmonary vein or respiratory conditions including COPD, interstitial diseases, sleep apnea and high altitude sickness for a long time. It may occur after thromboembolism episode or recurrent thromboembolism.

Symptoms

Difficulty in breathing is commonest symptom followed by weakness and fainting. Other symptoms include fatigue lethargy, loss of appetite, chest pain, cough, blood in cough, hoarseness of voice.

Diagnosis

X ray-chest and laboratory studies are the first investigations followed by echocardiography. Further investigations depend on the underlying cause. To confirm the diagnosis, right-sided cardiac catheterization may be done.

Treatment

Cases are treated with oxygen, pharmacological therapy and if required surgical intervention. In secondary cases management of primary condition is important. Pharmacological agents include calcium channel blockers, endothelin-receptor antagonists, Phosphodiesterase type 5 inhibitors, soluble guanylate cyclase (sGC) stimulators, prostacyclins, digoxin, and anticoagulants.

1. Simonneau G, GalièN, Rubin LJ, et al. Clinical classification of pulmonary hypertension. J Am Coll Cardiol. 2004;43(12 Suppl S):5S.
2. Runo JR, Loyd JE. Primary pulmonary hypertension. Lancet 2003; 361:1533.
3. Peacock AJ. Primary pulmonary hypertension. Thorax 1999; 54:1107.
4. Galiè N, Humbert M, Vachiery JL, et al. 2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS): Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC), International Society for Heart and Lung Transplantation (ISHLT). Eur Heart J. 2016 Jan 1;37(1):67-119.
5. Jacobs W, Konings TC, Heymans MW, et al. Noninvasive identification of left-sided heart failure in a population suspected of pulmonary arterial hypertension. Eur Respir J 2015; 46:422.
6. Berger M, Haimowitz A, Van Tosh A, et al. Quantitative assessment of pulmonary hypertension in patients with tricuspid regurgitation using continuous wave Doppler ultrasound. J Am Coll Cardiol 1985; 6:359.