Pulmonary hypertension, defined as a mean pulmonary arterial pressure greater than 25 mm Hg at rest or greater than 30 mm Hg during exercise. Pulmonary hypertension happens when the pressure in the blood vessels leading from the heart to the lungs is too high.
With pulmonary hypertension, the blood vessels to the lungs develop an increased amount of muscle in the wall of the blood vessels. The heart pumps blood from the right ventricle to the lungs to get oxygen. Because the blood does not have to travel very far, the pressure in this side of the heart and in the artery taking blood from the right ventricle to the lungs is normally low—usually much lower than systolic or diastolic blood pressure. When the pressure in this artery gets too high, the arteries in the lungs can narrow and then the blood does not flow as well as it should, resulting in less oxygen in the blood.
What causes pulmonary hypertension?
Some common underlying causes of pulmonary hypertension include high blood pressure in the lungs’ arteries due to some types of congenital heart disease, connective tissue disease, coronary artery disease, high blood pressure, liver disease (cirrhosis), blood clots to the lungs, and chronic lung diseases like emphysema. Genetics also play a role.
Pulmonary hypertension can happen in association with many other diseases, such as lung disease and heart disease. Heart failure is common in pulmonary hypertension.
The World Health Organization (WHO) has divided pulmonary hypertension into five groups on the basis of similarities in pathophysiology, clinical presentation, and therapeutic options. These groups include the following:
- Group 1 – Pulmonary arterial hypertension (PAH)
- Group 2 – Pulmonary hypertension due to left-sided heart disease
- Group 3 – Pulmonary hypertension due to lung diseases and/or hypoxia
- Group 4 – Chronic thromboembolic pulmonary hypertension (CTEPH)
- Group 5 – Pulmonary hypertension with unclear or multifactorial etiologies, including hematologic disorders (eg, myeloproliferative disorders), systemic disorders (eg, sarcoidosis, pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis, neurofibromatosis, vasculitis), metabolic disorders (eg, glycogen storage disease, Gaucher disease, thyroid disorders), and miscellaneous conditions (eg, tumor obstruction, mediastinal fibrosis, chronic renal failure on dialysis)
The overall prevalence of pulmonary arterial hypertension (PAH) is difficult to determine given the disease’s heterogeneity and likely underdiagnosis.
Increased pulmonary vascular resistance is the main pathogenic mechanism in pulmonary arterial hypertension (PAH). This is typically due to vasoconstriction, remodeling, and thrombosis of the small pulmonary arteries and arterioles.
SIGNS AND SYMPTOMS
Patients with PH may also have nonspecific symptoms secondary to pulmonary hypertension. These may include the following:
- Dyspnea upon exertion
- chest pain
- syncope with exertion
- Right under quadrant pain
Less common symptoms include the following:
- Hoarseness (due to compression of the recurrent laryngeal nerve by the distended pulmonary artery)
Management of pulmonary hypertension (PAH) is multifaceted and consists of supportive therapy as well as advanced vasodilatory therapy.
Supportive therapy includes:
- oxygen therapy
- Medications e.g Sildenafil, Digoxin
- Lung transplantation
- Right-sided heart enlargement
- Heart failure
- Blood clot
- Mayo Clinic