Heart palpitations in a young female

Dear Ask The Doctor: For about a year now I've been having heart palpitations, which follow with dizziness/confusion. It is mostly moderate but can sometimes be really bad. When its bad it appears my whole body is shaking, but really its my heart beating so hard it shakes my whole body, i have also come very close to loosing conciousness. Within the last few months I have also experienced fast heartbeat, slow heartbeat, inability to catch breath, sleeplessness and headaches. This can happen a few times a day to a few times a month. I am only 17 years old and thats why it worries me. Also it happend while i was driving once which really freaked me out. I'm 5'4, 130 pounds, ive never had any pre existing health problems and I drink lots of water and I dont eat junk food. It happens without any warning, and it doesnt matter if im sitting down or standing up. Any suggestions would be great, thanks!

Dear Kelsey: There are many reasons for palpitations or the sensation of irregular heartbeats. These can include premature ventricular complexes, which are generally benign, but sometimes the sensations may be caused by heart rhythm abnormalities. The only way to diagnose the cause of your symptoms is to get a heart tracing during these episodes. From the symptoms you describe, I advise attending your family doctor for a full history and clinical examination. He can perform an ECG (electrical trace of the heart) and may refer you for a 24 hour Holter (heart) monitor. This records a 24 hour electrical trace of the heart and will check for any heart rhythm abnormalities. He may also refer you to a cardiologist for specialist advice if any arrhythmias are recorded.