<s>[INST] I woke up last night with my heart racing. I was breathing slowly to calm my heart, but it kepts pumping extremely quickly. My depth perception is off and earlier my vision was blurry. I was shaking through all of this. Dad says its an anxiety attack. [/INST] Hello, This can be anxiety attack but will not wake you up from the sleep, I am keeping it lower down. This can be arrhythmia like PSV or atrial fibrillation, where your heart rate suddenly goes up and BP falls. These are episodic tachycardia and your ECG may be normal if you are not having tachycardia during ECG. You will need evaluation like thyroid test and holder monitoring. You should also get one hemoglobin levels done. So visit nearby cardiologist for this investigation. Also, to abort such episodes you should try to cough hard. Is there any stress or anxiety associated. Till the time your evaluation is complete, you can ask your local doctor for tab collar LA 20 mg once a day. If none of the above is successful then last option is of electrophysiologist studies which is invasive test which can diagnose and treat the arrhythmia permanently in most of the cases. Hope I have answered your query. Let me know if I can assist you further.  </s>