A vq is physiological vs anatomical.
V = ventilation
Q= perfusion= Blood/ time/ tissues ( volume)...
But it sounds almost more like gerd or a hiatal hernia may be at play here...
That would require
An endoscopy and or barium swallow, and or manometry.
Do you get heart burn?
Echo with bubble simply uses agitated saline and ultrasound... completely safe.
It could be as simple as gerd or hiatal hernia.
But I do think you shouldnt let it go. It's your health and you should pursue it with other clinicians if you still feel bad.
Things often get over looked!!
I think you need a more comprehensive panel of testing.
Have you had a vq scan?
Chest ct/cta?
Echo with bubble?
To start with.
Did you have a stress test with imaging? If so these things are about 97% accurate in finding heart disease. The next test would be an angiogram which carries a very real risk of complication and I doubt anyone would do one without additional symptoms. You may be best served by getting a second opinion.