Okay I am in my 20s, and I have done, in the past 1 year the following tests:
1. 4x 12-lead ECG
2. 1x 24hr Holter ECG
3. 1x Echocardiogram
All of them came back normal, the 24hr tape noticed 20 PVCs, 1 SVE, and some (esp. after exercise) sinus arrhythmia. For the 24hr tape I should specify that I also did a 15min run during it, and heart rhythm was normal even at my max heart rate (190bpm).
Now, I haven't been doing any exercise for quite a bit of time. Recently I started running almost everyday for a total of anywhere between 14-25mins each run. I had no problems in the beginning, although I did have to push myself. But now, after several days of doing that, I notice a few problems. For example, I took a hot bath after the run today (I waited 1hr before taking the bath after finishing the run) and started feeling sick (weak, and feeling SLIGHTLY short of breath - but no wheezing, etc.). I had dinner normally, but couldn't eat as much. Pulse oxymeter indicated high oxygen saturation of 97-98%, with heart rate fluctuating between 80-100 (with sinus arrhythmia pattern). However, upon standing up, or climbing stairs, heart rate would climb a lot compared to how it would change normally. For example it would go from 90 to 140, and I would also experience shortness of breath while this lasted although oxygen saturation would be normal (lowest recorded being 95%). Sometimes in this period I also had a few PVCs, which seem to be more common after I started training again than they were before, when I have done the Holter. Probably with a frequency of say 1 ectopic in 5mins. In terms of blood pressure, I took it and it was 138/84 with pulse 90bpm. My BP generally is 130-140/80-90 and I take no medication.
So my questions are as follows. Why is it that after training, especially when I have trained multiple days in a row, my heart reacts so quickly to small changes like standing up, climbing, or shouting (I get 140 heart rate + slight shortness of breath even if I shout in this time frame)? Also, what could cause the increase in PVCs? Part of the reason why I'm asking this is that I want to understand my body, and part of the reason is that I'm wondering if there is anything dangerous about these times - and if so should I stop running for a few days and then re-start again? Thanks everyone! :)