Possible Missed Heart Attack: Unexplained Elevated Troponin Levels

I went to the ED a while back for flu-like symptoms and fever after a surgery. They admitted me due to elevated troponin levels (243) and tachycardia at rest (118bpm). I had an EKG, echo, and chest xray, but was only told they looked "fine". I was eventually discharged with the one word diagnosis "pericarditis," no meds, and no explanation or plan other than to follow up with my PCP. At my follow-up, I was told I had an enlarged heart and decreased ejection fraction, and that we'd "keep an eye on it." Nothing has been mentioned since and there was no elaboration. Anything more than general getting around has my heart rate shooting up to the 140s and leaves me exhausted. I've been having palpitations; my heart skips beats and I get a fluttery, empty feeling in my chest that leaves me lightheaded. Is it possible I had a heart attack that was missed? I've read heart attacks and pericarditis can read similarly on EKGs. Male | 36 years old Complaint duration: 8 months Medications: lisinopril 10mg Conditions: high blood pressure, obesity, high triglycerides, prediabetes