Hi, I have been having episodes of blacking out very briefly followed by swallowing difficulty, squeezing in the chest and racing heart.  i am a 40 yr old female and i do have heart arrythmias such as PVCs,PACs and Inappropriate Sinus Tach.  I also have a B12 deficiency but get monthly injections for those.  What could be causing my symptoms?
Thanks for your question on Chat Doctor. I can understand your concern. Since you are known case of various heart arrhythmias, possibility of worsening this arrhythmia is more because you're all symptoms like chest tightness, squeezing in chest, rapid pulse rate etc. are common symptoms of uncontrolled arrhythmia. So immediately consult cardiologist and get done 1. ECG 2. 2d echo 3. Holder monitoring (24 hours continuous recording of ECG). You may need radio frequency ablation (RFA) surgery for permanent treatment of arrhythmia. So consult cardiologist and discuss all these. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.