I struggle with anxiety and panic attacks and have elevated blood presssure when I'm stressed. My blood pressure returns to normal, but I was wondering if episodic high blood pressure can cause an enlarged heart like hypertension can.?

Stress management. Frequent spikes in blood pressure (labile hypertension)are harmful but may not cause enlargement of the left ventricle such as occurs in longstanding sustained hypertension. I recommend stress management therapy for you as well as careful follow-up by your MD who will guide you on diet,etc.