Table 2 Receptor pharmacology and physiology affecting the right heart

Phenylephrine

(10 mcg/min–200 mcg/min)

Pure α₁ receptor agonist

Increases systemic vascular resistance (SVR), potential to increase pulmonary vascular resistance

Norepinephrine

(0.02 mcg/kg/min–0.3 mcg/kg/min

Or (1–20 mcg/min)

 α₁, β₁ receptor agonist

Increases in SVR may have some effect on contractility and HR

Epinephrine

(0.02 mcg/kg/min–0.3 mcg/kg/min)

Or (1–20 mcg/min)

α₁, β₁, β₂ receptor agonist

Increases SVR, increases HR, increases contractility

Dobutamine

(0.5 mcg/kg/min–20 mcg/kg/min)

β₁, β₂ receptor agonist

Increases HR, increases contractility, may lead to hypotension in some patients

Dopamine (0.5 mcg/kg/min–10 mcg/kg/min)

δ₁, α₁, β₁, β₂ agonist

Increases SVR, Increased HR, Increased contractility

Isoproterenol (2–10 mcg/min)

β₁, β₂ agonist

Increases HR, increases contractility

Milrinone

(0.1 mcg/kg/min–0.5 mcg/kg/min)

Phosphodiesterase III inhibitor

Increases contractility and decreases pulmonary vascular resistance (PVR), may lead to hypotension

Vasopressin

(0.02 U/min–0.04 U/min)

V₁ receptor agonist

Increases SVR through splanchnic vessels, no effect on pulmonary vasculature can counteract Milrinone-induced decreases in SVR, no effect on HR

Inhaled Nitric Oxide (1–20 PPM)

Activates soluble guanylate cyclase

Decreases PVR

Inhaled Epoprostenol (0.01–0.1 mcg/kg/min)

Synthetic prostacyclin

Decreases PVR