Can stress and anxiety cause an irregular or rapid heart beat? I ve been through every test there is since I had a really scary tachycardia and every doctor I have seen says that my heart is fine and something else is causing the rapid and irregular beats. My condition has not improved and you can trust me that they have checked everything. I don t think it is possible that I am causing this symptom, but could my subconscious or my nervous system be causing this? I ve been reading up on it and it would explain why my doctors can t find the source but yet acknowledge the problem. if more details will help then read my previous questions I have asked. Thanks.