not sure if rx bricks is a reliable source, what do amboss/utd/uptodate say?
I remember this being contentious topic from our pharmacologist. I wouldn’t change this card because all class IIIs inhibit different potassium channels at phase 3 but some inhibit at phase 2 (all the -tilides inhibit IKr which is active during both phase 2 + 3 [source: Cardiac Delayed Rectifier Potassium Channels in Health and Disease - PMC] while amioderone, for example, inhibits HERG which is only present in phase 3 [source:Classification of antiarrhythmic agents | Deranged Physiology]). You can phase 2 AND 3 prolongation on page 330 of FA 2022. However, most tested/focused on (sorry don’t have a source for this) is the prolongation of phase 3 because that is the main effective consequence (the prolonged repolarization) as well as the main phase overlapper among the class III drugs.
I would potentially add “main focus is on phase 3” in the extra section. Here’s a good source overall for this topic: Classification of antiarrhythmic agents | Deranged Physiology
So maybe change it to “phase {{c1::3 (primarily)}} and {{c1::2}}”