Atrial Fibrillation (AFib) Support Group
Atrial fibrillation (AF or afib) is an abnormal heart rhythm (cardiac arrhythmia) which involves the two small, upper heart chambers (the atria). Heart beats in a normal heart begin after electricity generated in the atria by the sinoatrial node spread through the heart and cause contraction of the heart muscle and pumping of blood.

Chatty Bill
As to being 66, theres a song by Udo Jrgens called At 66 (its in German) my really free translation of the refrain goes something like this:
at 66, thats when life begins
at 66, thats when the fun kicks in
at 66, you pick up speed when
at 66, youre nowhere near the end!
Carpe diem,
atp