Pulmonary Hypertension

Today we discussed a great case of severe pulmonary hypertension complicated by acute right heart failure. A few learning points: 

1) The physical exam in pulmonary hypertension:

  •  The  feature with the best operating characteristics according to this review is the loud P2 with a LR of +3.2
  • Other things that may tip you off are a right ventricular heave, a right-sided S4, murmur of tricuspid regurgitation, and the height of the JVP

2) Echocardiographic findings in pulmonary hypertension: 

  • Elevated RVSP (RVSP is an approximation of pulmonary arterial systolic pressure= PASP)
    • RVSP~PASP= tricuspid valve pressure gradient + CVP
    • mean pulmonary artery pressure= 0.61* PASP +2 (mild 25-40, mod 40-55, severe >55 mmHg)
  • Dilated pulmonary artery (greater diameter than the aorta)
  • Right atrial dilation
  • Bulging of the septum leading to LV dysfunction
  • Triscuspid regurgitation
  • Causes can be identified: left heart disease (systolic dysfunction, left atrial outflow obstruction such as atrial myxoma, aortic/mitral disease, shunts, PE)

3) Gold standard of diagnosis for pulmonary hypertension is by right heart catheterization and determination of mean pulmonary artery pressure, which should be greater than 25 mmHg. 

4) The classification for pulmonary hypertension by WHO is: 

  • Group 1: Pulmonary Arterial Hypertension: idiopathic, familial (BMPR2, etc), drugs and toxins (amphetamine, methamphetamine, cocaine, fenfluramine, St. John's Wort), connective tissue diseases (systemic sclerosis, RA, SLE), HIV, chronic liver disease/portal hypertension, congenital heart disease (Eisenmegers' or left to right shunt), schistosomiasis 
  • Group 2: Left heart disease: systolic or diastolic dysfunction, mitral or aortic disease, constrictive pericarditis, restrictive cardiomyopathy
  • Group 3: Chronic lung disease/hypoxia: COPD, ILD, OSA, pulmonary fibrosis
  • Group 4: CTEPH: chronic thromboembolism 
  • Group 5: multifactorial: chronic hemolytic anemia, myeloproliferative disorders, CKD, sarcoid

5) Finally, the cornerstones of management include: 

  • Diuretics; caution however as these patients are preload dependent
  • Supplemental oxygen if needed
  • Anticoagulation for type 4 (controversial for type I) 
  • Consider digoxin for type 3
  • Exercise training
  • Proper vaccinations including pneumococcal and influenza
  • Treatment of underlying disease
  • Consider advanced therapies particularly for type I: phosphodiesterase inhibitors, calcium channel blockers, endothelin receptor antagonists, prostanoids