@bama921, I take 25 mg spironolactone along with 25 mg hydrochlorothiazide for high blood pressure (primary aldosteronism). I don't have issues with Afib but do use a Kardia mobile device every morning along with my Apple watch to check. The Apple watch series 9 always shows Sinus Rhythm but the Kardia device normally shows Sinus Rhythm with Supraventricular Ectopy and once in awhile will show with Wide QRS or just plain Sinus Rhythm. Once in awhile it will also show Afib but I don't feel any symptoms or differences.