Question: I am 27 year old female and aside from mirena for endometrial hyperplasia, I am otherwise healthy and do not take any other medications. I weigh 151 lbs at 5'3. My heart rate normally sits at 86. I presented to the ER last night with chest pain, shortness of breath, and dizziness. I was laying in my bed reading at the time the chest pain started. I immediately sat up in my bed because I could not breathe well. Immediately upon arrival at the ER they did an ECG. The findings were "sinus tachycardia with possible left atrial enlargement borderline ecg" blood pressure was 135/89. I had surgery December 14 to have pins placed in my pinky finger that I broke. They checked my D-dimer which was normal as well as thyroid levels all being normal. They did a chest X-ray which was clear. I have not had any sort of sickness no cough etc. ER dr diagnosed me with costocondritis sent me home with 500 mg naproxen and tramadol. My chest pain has continued into today as well as dizzy spells and feeling my heart beat inside of my throat. If this was costochondritis why would the chest pain start whenever the tachycardia starts. I can feel the increase in my heart rate and immediately upon the increase the chest pain starts. Should I seek a second opinion or should i follow the treatment plan the ER dr gave me?