I get heart palpitations that I can feel all day and night in my chest and head. What is the cause?

Hi doctor,

I am a 25-year-old female with a weight of 58 kilograms and a height of five feet. Before three months, I went to the doctor with a thumping chest. I had a similar feeling in my head and ears with headache and tiredness. The Holter monitor result was normal. ECG and brain MRI were normal. All the blood result was normal except iron with a value of 13 g/dL. I started taking Maltofer. My symptoms went away and I was feeling normal. Before two months, all my symptoms returned back. I did the blood tests again.

My iron level remained low with a value of 19 g/dL. After that, an iron infusion was done. Stool examination and blood test were done. All the results came back normal. FOBT test was positive. The doctor advised me to have a colonoscopy though I seem to be normal. They told me that these symptoms will get cleared when the iron level becomes normal.

Now I am having heart palpitations and I can feel it during the day and night in my chest and head. I can hear my heartbeat in my ears too. It disturbs my sleep and all my symptoms are really noticeable when I am lying quietly in my bed. The doctor prescribed me Mirtazipine to have good sleep. I have not taken it. I need a second opinion.