<s>[INST] Ive been having the sensation like someone is squeezing my heart in their hand and letting go and doing it again. Also my heart races up too 140. My chest xray and ekg were normal. Any other tests I should be requesting? My Dr doesnt feel like this is a big deal. [/INST] Hi, Increased heart rate & palpitations can have a lot of causes. It can be normal sinus tachycardia due to anxiety or stress, or it could be abnormal supra ventricular tachycardia. For the diagnosis, you need to do ECG at the time of palpitation & tachycardia. If the duration of palpitations are short enough to reach a nearby hospital, we put a 24hr ECG monitoring (Holder Monitor). You also need to do a 2D Echo & thyroid function test to see for any associated abnormality if any. </s>