I have had two heart attacks and suffer from Chronic indigestion and acid reflux.
The symptoms are very similar and they are often confused, so you cannot take any chances. I had no other common symptoms.
The first time I had a heart attack, I was suffering from a severe allergic reaction to new medication and thought the indigestion was caused by that. DH faffed about, phoning NHS 24. The ambulance took hours to come and it was only when I was in A&E, and tests done, was the heart attack diagnosed. I was very lucky indeed! It turned out I had an undiagnosed heart condition, caused by my RA.
The second time it happened, I dialled 999 myself, was very precise with my symptoms and medical history and the ambulance was there in 15 minutes. I had indeed had another heart attack.
Take no chances if it happens to your DH.
You should have aspirin at home, because the first thing the ambulance call centre do, is tell you to take a specific dose of aspirin right away. As soon as you get to hospital, blood is taken, which shows what your Troponin levels are. It takes four hours for the result to come back. If they are traised, you need another blood test to check again.
I hope this helps.