Inotropic Therapy in ADHF

Question 1

Inotropic Therapy Indication in ADHF

Answer 1

Cold and wet (Forester subset IV) or cold and dry exacerbations (Forester III) (if PCWP > 15 mm Hg)

Question 2

Dobutamine Mechanism of action

Answer 2

β1-Agonist: Stimulates AC to convert ATP to cAMP to ↑ CO; slight peripheral vasodilation

Question 3

Dobutamine Clinical effects

Answer 3

Positive inotropic, chronotropic, lusitropic effects

Question 4

Dobutamine Dosing in ADHF

Answer 4

Start 2.5–5 mcg/kg/min IV; max of 20 mcg/kg/min

Question 5

Dobutamine Elimination

Answer 5

Half life = 2 min, Hepatically metabolized (inactive), renally eliminated

Question 6

Dobutamine AEs

Answer 6

hypokalemia, myocardial ischemia, tachyphylaxis

Question 7

Dobutamine over Milrinone in ADHF

Answer 7

Dobutamine may be favored in: Severe hypotension, Bradycardia, Thrombocytopenia, Severe renal impairment

Question 8

Milrinone Mechanism of action

Answer 8

PDE inhibitor: Inhibits cAMP breakdown in heart to ↑ CO and in vascular smooth muscle to ↓ SVR

Question 9

Milrinone Clinical effects

Answer 9

Positive inotropic and lusitropic effects,
no direct chronotropic effects

Question 10

Milrinone Dosing in ADHF

Answer 10

Start 0.1–0.2 mcg/kg/min IV; may titrate to max of 0.75 mcg/kg/min

Question 11

Milrinone Elimination

Answer 11

half life = 1 hr, prolonged to 2–3 hr if HF or CrCl < 50 mL/min; 90% renal

Question 12

Milrinone over Dobutamine in ADHF

Answer 12

Milrinone may be favored: To avoid tapering or discontinuing home β-blocker, When pulmonary artery pressures are high