Positive Inotropic Agents
Start with the big picture
The lesson begins with the shared purpose of positive inotropes, then examines digoxin’s effects on intracellular calcium and vagal tone, its uses in symptomatic heart failure and atrial fibrillation, and its narrow therapeutic index. It connects digoxin toxicity and interactions with practical safety considerations. Dobutamine and dopamine are considered in acute low-output or hypotensive settings, including their adverse effects. The lesson then introduces milrinone and inamrinone as PDE3 inhibitors, emphasizing their combined inotropic and vasodilatory actions and short-term role in selected refractory cases. Levosimendan and a clinical summary table round out the topic, alongside key principles for understanding when these agents may be considered.
What you'll learn
- Explain how positive inotropic agents affect myocardial contractility and cardiac output.
- Describe digoxin’s mechanism, clinical uses, toxicity risks, and major interactions.
- Distinguish the clinical roles and adverse effects of dobutamine and dopamine.
- Summarize PDE3 inhibitor actions and their short-term use in selected heart failure settings.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
