I often experience shortness of breath when I walk and sometimes dizziness when I lift something, bend over, etc. I smoked for many years until quitting 2 years ago. I have had heart problems and I am afib with a defibrillator implanted because of an arythmia.
Are you sure about Atrial fibrillation and defibrillator implanted for Atrial fibrillation? I doubt if you are Atrial fibrillation patient if u have AID implant. Check again if its ventricular fibrillation. Your breathless can be explained by increase in heart rate or heart disease which you didn't mention.