Trying to understand aspects of the aging process better, as related to my own situation. Any advice?

Also, with regard to diagnosis in general, understand that one may have more than one condition. Left Ventricular thickening might certainly be there, but no related to anything else, and it does not mean that you don't also have asthma or emphysema. Sometimes, conditions are uncovered during a diagnostic workup that are benign and require no treatment.

Where do you live now? Are you retired? What are your functional abilities? If you are active and healthy, keep walking!

Do you have Medicare as your primary insurance?

The fact that your respiratory distress is not constant but intermittent would point to something less systemic and more a reaction to something, say an allergy that triggered asthma. Can you have yourself tested for allergies?