Pulmonary hypertension

Pulmonary Hypertension (PH): 

pulmonary hypertension news.jpg

Pulmonary hypertension (PH) is present when mean pulmonary artery pressure exceeds 25 mm Hg at rest or 30 mm Hg with exercise (Normal PA systolic pressures range from 10-30)

Definitive diagnosis via right heart catheterization, rare cause of SOB

In general, there is no cure besides supportive care and treating the precipitant, high rate of mortality


Pulmonary vasculature is meant to be a high-flow, low-resistance circuit.

Cardiac causes

LA or LV disease => ↑ LA pressure => ↑ pulmonary venous pressure => ↑ pulmonary artery pressure => ↑pulmonary vascular resistance

L to right shunt will also cause high pulmonary vascular pressure

Respiratory causes

hypoxic vasoconstriction -> PH

Which leads to => vasoconstriction => altered vascular endothelium and smooth muscle function

 => cellular remodelling => increased vascular contractility => lack of relaxation in response to various endogenous vasodilators => fibrosis of vascular tissue


Dyspnea (with rest or with exertion), Fatigue, Chest Pain, Syncope, Exertional lightheadedness

Patients with severe pulmonary HTN can develop signs of R heart failure (JVD, hepatomegaly, ascites, edema)


Five types of PH: 

Group 1: Pulmonary arterial HTN


Genetic/Heritable abnormalities

Drug/Toxin induced

Associated with known risk factors (HIV, liver disease, collagen vascular disorders)

Group 2: Pulmonary venous HTN (left heart disease)

Systolic or diastolic dysfunction

Mitral or aortic valve disease

Group 3: Chronic hypoxemic lung disease

Obstructive lung disorders (COPD)

Interstitial Lung Disease

Idiopathic Pulmonary Fibrosis

Sleep-Disordered breathing (OSA)

Group 4: Embolic disease (PE)

Group 5: Miscellaneous


The Workup


Most common abnormality is right axis deviation

Signs of R heart strain: S1Q3T3, right atrial enlargement in the inferior leads, incomplete/complete RBBB


CBC, CMP often nonspecific

BNP often elevated and correlates with outcomes

Elevations in troponin are associated with higher morbidity and mortality


Can demonstrate signs of RV failure – enlarged RA, RV, pulmonary arteries

Can demonstrate underlying etiology – hyperinflation, ILD, edema


Best initial diagnostic test

Apical four chamber helpful to evaluate size of RV relative to LV and assess for septal deviation

US not helpful in assessing volume status in these patients!



Start with ABC’s 

Give home medications

If known PH consult pulmonology early

Consider 3 Ps: Preload, Pump and Pipes

RV function determined by 3Ps: Preload, Pump, Pipes


Consider gentle hydration (250cc IVF) vs. gentle diuresis 


Cardiovert dysrhythmias as indicated

Consider inotropic support

Dobutamine 2-10 mcg/kg/min

Milrinone 50mcg/kg bolus -> 0.2-0.8mcg/kg/min (can cause hypotension)

Consider low dose norepinephrine (0.05–0.75mcg/kg/min) to maintain coronary artery perfusion

Pipes: (afterload)

Consider Pulmonary vasodilators

Prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 (PDE-5) inhibitors

Prostanoids are treatment of choice

Epoprostenol is the only therapy proven to improve survival

inhaled nitric oxide 20-40ppm (good in bypass, doesn’t cause systemic hypotension as inactivated when bound to Hb)

Treat underlying etiologies

If need to provide respiratory support consider doing it in consultation with pt’s pulmonologist:

Always start with NRB before positive pressure ventilation (PPV)

PPV can cause rapid cardiovascular collapse due to increased Pulmonary Vascular Resistance and decreased preload

If you must intubate, have vasopressors at bedside: phenylepherine + NE + vasopressin are all OK

Low TV, low PEEP ventilation strategy

aggressively treat hypercarbia, acidosis, hypothermia (all increase PVR), which can increase pulmonary vascular resistance, pulmonary artery pressure, and RV strain


References: LITFL, EMDocs, UpToDate