Pulmonary Hypertension: An Overview

Pulmonary Hypertension (PH) Overview

• PH is defined as elevated blood pressure in the pulmonary arteries.
• It results in increased resistance to blood flow within the lungs.
• Normal pulmonary artery pressure at rest is 12-16 mmHg mPAP.
• Pulmonary hypertension is often defined as >20 mmHg at rest, measured via right heart catheterization.

Classification of PH

• Group 1 (PAH): Includes idiopathic, heritable, or drug/toxin-induced causes.
• Group 2: PH arises due to left heart disease.
• Group 3: PH is associated with lung diseases.
• Group 4: PH occurs due to blood clots in the lungs.
• Group 5: PH has unclear or multifactorial mechanisms.

Symptoms of PH

• Dyspnea, or shortness of breath, especially during physical activity is a key symptom.
• Fatigue occurs due to decreased oxygen delivery to the tissues.
• Chest pain results from the strain on the heart.
• Other symptoms can be related to the cause of the condition.
• 27% Reported Fatigue
• 15% Reported Fainting or light-headedness
• 86% Reported Shortness of Breath
• 13% Reported Palpitations
• 22% Reported Chest Pain
• 21% Reported Edema (Swelling)

Signs of PH

• Jugular Venous Distension (JVD) is visible swelling of the jugular veins in the neck.
• JVD indicates elevated pressure in the right side of the heart.
• Hepatomegaly is the enlargement of the liver, which can be a result of congestion in the hepatic veins because of right-sided heart strain.
• Ascites is the accumulation of fluid in the abdominal cavity due to increased pressure in veins leading to the liver.
• Peripheral Edema occurs with swelling in the ankles and legs, due to fluid retention caused by impaired circulation.
• Clubbing of Fingers: Abnormal enlargement of the fingertips and nail changes due to chronic oxygen deprivation.
• Right Ventricular Heave or Lift: A visible or palpable pulsation of the chest wall, indicating increased workload on the right side of the heart.
• Splitting of S2
• Murmurs can include pulmonary regurgitation, tricuspid regurgitation, or functional pulmonary stenosis.

Complications of PH

• Right Ventricular Hypertrophy (RVH) happens because the right ventricle enlarges because of increased workload.
• Right Heart Failure can develop from progressive RVH.
• Arrhythmias lead to an increased risk of irregular heart rhythms.
• Hemoptysis, or coughing up blood, occurs because of increased pressure in pulmonary vessels.

Investigations for PH

• Blood Tests: Can involve BNP levels which may indicate heart failure and Blood Gas Analysis to assess oxygen and carbon dioxide levels.
• Imaging Studies: -An echocardiogram provides an initial assessment of pulmonary artery pressure and heart function. -An electrocardiogram detects abnormal heart rhythms and signs of right ventricular hypertrophy. -Chest X-rays reveal signs of PH, for example enlarged pulmonary arteries. -CT or MRI scans identify structural abnormalities and rule out other causes.
• Pulmonary Function Tests involve Spirometry to assess lung function and rule out obstructive lung diseases.
• Ventilation/Perfusion (V/Q) Scans are important for diagnosing chronic thromboembolic pulmonary hypertension (CTEPH).
• Right Heart Catheterization (RHC) is the definitive diagnosis as it measures pressures directly in the heart chambers, to confirming PH. -RHC also provides detailed information on the severity of PH.
• Genetic Testing for heritable forms is used in cases where a genetic component is suspected.
• Pulmonary Angiography is an invasive test occasionally used for detailed imaging of pulmonary arteries.

Treatments for PH

• Vasodilators help relax and dilate pulmonary blood vessels and include Drugs like prostacyclin analogs, Endothelin receptor antagonists, Phosphodiesterase-5 inhibitors
• Calcium Channel Blockers are used in some cases, especially in responders to vasodilator testing.
• Anticoagulants prevent blood clots.
• Diuretics manage fluid retention and reduce symptoms like peripheral edema and ascites.
• Oxygen Therapy improves oxygen levels in the blood and reduces strain on the heart.
• Exercise Training consist of Tailored exercise programs to improve physical capacity and overall well-being.
• Supportive Measures include Nutritional Support, as adequate nutrition is crucial for individuals with PH and Psychological Support to help with psychological challenges.
• Interventional Procedures: Pulmonary Thrombo-endarterectomy (PTE) involves surgical removal of chronic blood clots in the lungs with chronic thromboembolic pulmonary hypertension (CTEPH).
• Lung Transplantation is considered for advanced cases when other treatments are ineffective
• Management of Underlying Conditions focuses on treating the underlying causes, such as connective tissue diseases or chronic respiratory conditions.

Case Scenario

• A 42-year-old female presents with worsening shortness of breath over 6 months, dizziness, and ankle swelling.
• She denies chest pain or recent respiratory infections.
• Examination: Bilateral pitting edema, loud second heart sound (P2), systolic murmur.
• ECG: Right ventricular hypertrophy, right axis deviation.
• Echocardiogram shows elevated pulmonary artery pressures (mPAP of 32 mmHg).
• Right heart catheterization confirms pulmonary hypertension (mPAP ≥25 mmHg).