Pulmonary Arterial Hypertension

Primary or Idiopathic Pulmonary Arterial Hypertension is characterized by elevated pressures in the pulmonary circulation without any discernible cause. The heart’s right ventricle must work harder to pump blood at a higher pressure through the pulmonary vessels, which may ultimately lead to right heart failure. Due to its elusive origins, this subtype poses a significant challenge for diagnosis and treatment.

Primary or Idiopathic Pulmonary Arterial Hypertension is characterized by elevated pressures in the pulmonary circulation without any discernible cause. The heart’s right ventricle must work harder to pump blood at a higher pressure through the pulmonary vessels, which may ultimately lead to right heart failure. Due to its elusive origins, this subtype poses a significant challenge for diagnosis and treatment.

Group 3 relates to pulmonary hypertension due to chronic pulmonary diseases. In most cases, the underlying cause is chronic obstructive pulmonary disease (COPD), where the lung airways narrow and make it harder to exhale (e.g., emphysema). Other reasons may be interstitial lung disease, pulmonary fibrosis, sleep apnea, or rare lung diseases. The arteries in the lungs tighten, especially in those regions of the lung receiving less oxygen. Other vessels are tightened, which leads to elevated blood pressure throughout the lungs.

Pulmonary hypertension group 4 is called chronic thromboembolic pulmonary hypertension (CTEPH). This condition results from multiple blood clots (pulmonary embolism) that have occurred and/or if a blood clots in the lungs are not being dissolved. This ultimately leads to a blockage of normal blood flow through the lungs. In some cases, CTEPH may be treated through surgery (pulmonary thromboendarterectomy) to remove the blood clots.

Group 5 includes multiple that have in common that PAH is secondary to other diseases e.g. metabolic or immunological conditions.