Workout that is good for me?

Trying to find a good workout I can do. This must be low impact with little to no cardio as I have severe sinus tachycardia and a leaky heart valve. Among other heart issues. My doctor keeps telling me to swim but wants a spotter as I faint and my pulse raises very high. Looking for something I can do by myself as my hubby works 12 hour shifts. Any advice you help so much. Looking too lose 10 pounds
Workout that is good for me?
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