Squeezing burning sensation in the center of my chest

I suffer from major depression and when I have depressive thoughts, I experience a squeezing/burning sensation in the center of my chest which last for a few seconds, and recurs often. This only happens when I have depressive thoughts. I take medication for depression, but still whenever I have depressive thoughts, I experience this sensation in my chest. My aunt, who is a general doctor, told me this could be ‘ischemia’. I have had an ECG done many months ago, and apart from Sinus Tachycardia, there was nothing else in the results. I don’t know whether an ECG can diagnose the problem I’m having. Is this strange chest sensation anything to worry about?