Miscellaneous Antiarrhythmics
Start with the big picture
These agents influence rhythm through distinct pathways. Adenosine briefly suppresses AV-nodal conduction and is used for acute PSVT; its effects can be altered by caffeine, theophylline, and dipyridamole. Digoxin increases vagal tone to slow AV conduction, while toxicity may involve arrhythmias, gastrointestinal symptoms, or visual changes. Magnesium sulfate is a key treatment for torsades de pointes and digoxin-induced ventricular arrhythmias, and potassium correction can reduce ectopy associated with hypokalemia. Atropine reduces vagal influence to raise sinus rate and improve AV conduction in symptomatic bradycardia or AV block. Ivabradine slows the sinus rate by inhibiting the If current without reducing contractility. Across these options, electrolyte status, renal function, interactions, and agent-specific cautions are important.
What you'll learn
- Explain how adenosine transiently suppresses AV-nodal conduction and identify its role in acute PSVT.
- Describe digoxin’s effect on AV conduction and recognize key features and risk factors of toxicity.
- Summarize the roles of magnesium and potassium in arrhythmia management.
- Identify when atropine or ivabradine may be used and note their main cautions.
- Compare mechanisms, clinical roles, and safety considerations across these agents.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
