GERD and dance / run?

I have heart palpitation and tachycardia also PAC so the doctor advise me to excersize but for cardio i have to reach my target heart rate and sustain that range so to get that i have to do intense excersize. The best one for cardio is running but i can't do that since id feel sick but walking is not enough that's what my doctor said. So i do fast walking regularly also dancing since i love dancing. I thought maybe that could help too (i hope) but i dont force myself so if i feel bad i take a rest untill i feel fine and continue. I've been doing that for a couple of months regularly and i feel fine untill now. But i read that dance can make GERD worse so i'm worried. Have any of you with GERD tried dancing or aerobic? And so what happened? What are the signs that you shouldn't do it? If you don't experience burning/reflux/pain during/after excersize, does it mean it's okay to continue? But i'm worried if it can make it worse or maybe months later.