How worried should I be?

Father has it. He was driving a month ago and had blurry vision and palpitations and now did ECG's. Doctor's think that's it but doing some more testing to confirm.

I know I'll be tested next through an ECG, which is already scheduled. My established bradicardia seems like it will be a yes.

Changes to my life are now in order, but I need to understand how concerned I should be for my father? He's overweight. 20+kgs and eats high amounts of sugar daily, active from a physical job but no workout and poor posture. To me it seems like he just got the "last chance to get it together before you die". Am I wrong to assume this?