Pulmonary Hypertension

Relatively uncommon disease process, with an estimated incidence of 1–5:100,000.

Frequently identified as a contributing cause of death in USA, resulting in 6.5:100,000 deaths (2010).

Left heart disease underlies 60–85% of pHTN cases.

Primary pulmonary disease (e.g., COPD/OSA) is the second most common etiology.

Chronic thromboembolic disease causes pHTN in 2–4% of pts after acute PE.

Primary PAH is rare but most amenable to medical therapy.

RV failure

Atrial tachyarrhythmias

Hemodynamic instability

Hypoxia/hypercarbia: Causes pulm vasoconstriction and decreases myocardial contractility, which can lead to RV pressure and volume overload and ultimately RV failure.

PE: Consider urgent intervention (surgical or thrombolytics) if hemodynamically unstable.

Hypotension: Decreases RV perfusion and preload, which can worsen failure.

Atrial tachyarrhythmias: Atrioventricular coupling ensures adequate preload.

Sympathectomy (if neuraxial blockade present): Disrupts RV homeometric autoregulation in addition to systemic vasodilation.

Defined by mean PA pressure (MPAP): ≥25 mm Hg

• Mild: 25–40 mm Hg

• Moderate: 41–55 mm Hg

• Severe: >55 mm Hg

pHTN is often occult but presents symptomatically with increasing DOE (graded by NYHA classification).

Diagnosed with RHC.

PA pressures can be estimated on ECHO by utilizing the modified Bernoulli equation and maximal velocity of the TR jet, if present. (RV systolic pressure >40 mm Hg, which roughly correlates to MPAP >25 mm Hg.)

Primary periop morbidity and mortality results from RV failure, organ hypoperfusion, and arrhythmias.