If during an acute tachycardia episode with chest pain & sob, ekg shows increase in pwa, prolonged p-wave duration, and st depression, but ekg returns to normal after the episode. do i still need to be concerned? is this just stress or something more?

The episode described may be aggravated by stress, but with the results included in the question, a cardiologist should be consulted as at age "45", these types of findings may indicate the need for more testing, and coronary vessel evaluation.

P waves can become temporarily tall& peaked during rapid sinus tachycardia but other abnormal morphology at rest ( wide,notched) can be a sign of atrial pathology. Physiologic ST depression during rapid heart rates are upsloping. Downnsloping ST segments can be caused by coronary artery blockage. As has been recommended a cardiologist can conduct an evaluation. in view of associated chest pain