An elderly relative with a pacemaker and AF attended Casualty with acute pain in the right eye. The duty ophthalmic registrar carried out a thorough examination and reported that her eye was absolutely fine.
3 days later she returned with severe iritis associated with H.zoster. Antiviral treatment came too late. She lived with daily and often severe post herpetic neuralgia and ultimately lost the sight in that eye.
No connection with AF of course but I will definitely have the vaccine when I turn 70.