@1wife The idea of AADs is to restore normal rhythm, and it usually means a reduction in heart rate at the same time if it's one of the tachyarrhythmias. But that reduction in rate is an artefact of the regulation and restoration of rhythm, not the goal per se. Is it his experience that AADs reduce his HR into bradycardia territory, say less than 50 BPM, that makes him light-headed and windy?