fast pulse

I seem to always have a high pulse rate. Not too long ago I went to the er for strept throat and it was 150. Just now, after walking up a flight of stairs it was 154. There was only 10 stairs, not too many. After reaching the top I was light headed and my ears were ringing. What does this mean?? Also I have worn the heart monitor for 24 hours and had an ultra sound on my heart when i was 18 (im now 26) The cardiologist diagnosed it as tachycardia and said theres nothing to worry about, my heart just beats faster than normal. Well it seems to be getting worse.  I have chest pains fairly often its almost like a cramp you get in your side after running but in my chest when I have these pains it feels like everything I swallow (food, water, anything!) gets stuck in my throat and asphogus. i currently do not have health insurance. any sugggestions what this could be?

[Dr Santos]

Hi,
How are you? What other symptoms are present? Tachycardia is usually attributed to disruption of the normal electrical impulses that control the rhythm of the heart's electrical system. Factors such as damage to heart tissues from heart disease; abnormal electrical pathways in the heart present at birth; disease or congenital abnormality of the heart; high blood pressure, medication side effect, imbalance of electrolytes, or overactive thyroid may be responsible. Sometimes the exact cause is not known. It is best that you check with your doctor for proper evaluation. Since the last work-up was 8 years ago, recent diagnostics may also be indicated. Try to avoid smoking, drinking too much alcohol or caffeinated beverages. Take care and do keep us posted.