Reduce preload – increased excretion of sodium and water.
Diuretics
Prevent conversion of angiotensin I to angiotensin II – increasing plasma renin levels and reducing aldosterone secretion. Reduce preload via venous dilatation and afterload by decreasing peripheral vascular resistance (angiotensin II is a potent vasoconstrictor).
ACE inhibitors enalapril, captopril, lisinopril
Competes with aldosterone for receptor sites in distal renal tubule, increasing water excretion whilst retaining potassium and hydrogen ions.
Aldosterone antagonists spironolactone
Increase stroke volume and decrease contractility and left ventricular size. Long term administration blocks the damaging effects of overactive sympathetic activity.
Beta-blockers atenolol
Positive inotrope and vasodilator with little chronotropic (increasing heart rate) activity. Also has lusitropic (myocardial relaxation) activity to help myocardium relax.
Phosphodiesterase III inhibitor – milrinone
Cardiac glycoside inhibits Na/K ATPase that increases intracellular Na + and secondary increase in intracellular Ca+ + increasing force of contraction.
Digoxin
Catecholamine that stimulates β1 , α1 and dopaminergic receptors in a dosedependent fashion. Lower doses cause vasodilation via dopaminergic receptors in renal and splanchnic vascular beds. Mid-range doses act on β-receptors to increase heart rate and contractility. High doses act on α-receptors to increase systemic vascular resistance and increase blood pressure.
Dopamine
Sympathomimetic with stronger beta than alpha action. Increases contractility via β 1 stimulation and produces systemic vasodilation via β 2 receptors.
Dobutamine
α-agonist – increases peripheral vascular resistance. β2 -agonist – positive chronotrope and inotrope.
Adrenaline
Vasodilation by relaxing vascular smooth muscle and increases the inotropic activity of the heart.
Nitroprusside
Provides symptomatic improvement in pulmonary hypertension
Oxygen
Systemic and pulmonary vasodilator
Calcium channel blockers, e.g. nifedipine or amiodipine
Potent and selective pulmonary vasodilator acts via cyclic GMP pathway
Inhaled nitric oxide
Oral or IV phosphodiesterase-5 inhibitor, increases GMP levels and endogenous nitric oxide effect
Sildenafil, Tadalafil
Oral soluble guanylate cyclase stimulator, increases GMP levels
Riociguat
Endothelin receptor antagonist; competitively binds to endothelin-1 receptors reducing smooth muscle cell proliferation
Bosentan and Macitentan Ambrisentan
Pulmonary vasodilator and inhibitor of platelet aggregation; acts on cyclic AMP
pathway Oral, subcutaneous, inhaled and IV preparations
Prostanoids
