My ectopic atrial tachycardia is just present while heart is under stress and hr does not exceed 170 bpm at its worst. is that ok or is it dangerous?

Let's go with urgent: Supra ventricular tachycardia (SVT) radically compromises cardiac output which is tolerated in a young healthy male but potentially disastrous in, and often triggered by, other illness and aging. It's caused by an errant electrical pathway and can be corrected with ablation . Find a cardiologist who specializes in electrophysiology and get this fixed while you are healthy rather than emergently

Medical management: Consult a cardiologist- rates that high can be treated medically.