Brief Answer:
Need work up and management, psychological dyspnea

Detailed Answer:
Thank you for asking!
Difficulty breathing / dyspnea and neck muscle pain bilaterally with cardiac history of bypass surgeries and hip replacements multiple times and geriatric age limits of 70 needs first and foremost evaluation for cardiac profile functions, As you said it was done and nothing was noted significant, which is a good thing as it leaves innocuous things for the reason.Once ruled out for cardiac cause then next thing needs to be assessed thoroughly should be lungs and complete pulmonary functions assessment should be done as old age might lead to lung capacity and functioning compromise like COPD, Pneumothoraces etc. Simple anxiety and panic attacks may also present with such episodes and then named as psychological dyspnea. Plus also pollens and allergies may also cause that but i am not sure about that as there might be some allergy history as pollens cant cause that trouble with no history in the past of 70 years and not possible all of a sudden when immune system is not that functioning to give allergic reactions.
Nut shell, Stop worrying, Get a visit to your cardiologist and pulmonologist first thing in the morning on monday and let them sort it out if there is any thing to worry about and manage that accordingly. You have been cleared by ER so no imminent danger. Try some bronchodilators and inhaler steroids if still difficulty breathing, oxygen from portable homemade cylinders can also be tried.
You will be fine.Just let your professionals make it sure on monday. I am sure everything will be as normal as humanly possible. And they will connect the dots for these recent symptoms and give you a diagnosis and reason after some workup and history based examination and complete clinical correlation.
I hope it helps. Dont forget to close the discussion please.
May the odds be ever in your favour.
Regards
S Khan

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