noreaster,
Thanks for the post.
The symptoms you describe could be associted with POTS. I would want to know what rhythm you are experiencing during your episodes of tachycardia. POTS is a diagnosis that would come from more data collection but could be consistant with what you describe. Alot of people can have similar symptoms with the occurence of PVCs and be misled by taking their own pulse.
If it is POTS, its not straining the heart in a way that can damage it. But the symptoms can be quite bothersome.
In the setting of a normal heart, you have a very low risk for any problems at your age. However, lifestyle modifications incorporating diet and exercise at this stage can have significant implications in your later life. Stay away from smoking.
good luck
Hey. Quit last July but struggling so thanks for support. :-)