You need to see your doctor soon. Check for swelling in legs and abdomen. Right side heart failure results in swelling, water retention in the legs and abdomen. Left side heart failure results in water in the lungs. Your main right artery may be plugged. Doctor can put a stent in the artery, which is considered a procedure and not open heart surgery. If this is the case, you will feel a whole lot better.
Take care and see your doctor.
You should advise your physician of this new symptom. Because your heart function is compromised, it is really important to inform your physician of the rapid heart rate and near fainting episodes.
Please let us know how you're doing. Take care.