Can you take walks rather than do the elliptical? Do you have tachycardia walking? I have afib and try to deal with triggers first even if limiting!

Tachycardia is considered dangerous when it exceeds 100 BPM indefinitely...certainly more than 24 hours. This is just my personal opinion, but I believe it is increasingly being taken as a reasonable reduction in the upper limit by cardiologists: a heart rate (HR) near or above 100 BPM suggests something is not right. The vast majority of children and adults have resting HRs between 45 and 80 BPM, either sex. When you see an HR above 85, and you're not getting wound up about an election, or your finances, or you're not walking around or doing some gardening, then you should seek at least a safety check by a physician....who should offer to run some tests.

Yes, for some, not everyone, an adjustment of Vagus nerve tone can bring the rate down to a safe level. HOW YOU DO THAT will be a personal investigation as only one or two of the YouTube videos will show you a method that will work for you. The rest won't. But the truth is that, for you....mebbe...you will be further ahead, first with an investigation by a cardiologist, and secondly on a drug LIKE metoprolol, but there are others if metoprolol proves.....PROVES...to be the culprit in how you feel. Diltiazem is such a drug. There is also bisoprolol.

This novel cardiac behaviour (Canuck spelling) is an indication that something about your heart's substrate (you can look up 'cardiac substrate' ) has begun to change. For the heart, and any major organ, you want to get on whatever-it-is as soon as possible while it is the most tractable that it will ever be. With heart arrhythmias/dysrhythmias, you want to deal with it as early as possible when it is still 'young'. Don't put this off!