Hi, welcome to our site. I am Dr Saumya Mittal. Read your query. That is a very significant question and i appreciate your problem. I will try my best to answer your query You are probably developing an arrhythmia. I would suggest getting an ecg. If the heart beat had been going fast in the crowd, i would have said claustrophobia. But since its happened at home, i think thats less possible. Is it possible you were dehydrated by excess sweating. in that case take plenty of fluids, and have electrolytes tested too I hope this helps you. Inform the reports mentioned above so i can be of help further. Best of luck. I have given you the answer to the maximum considering the information provided. The results of the tests could further enhance my answer to you. Please do understand that some details could be extracted from a detailed history and examination. Looking forward to your return query with the details asked so that I can help you further. (If the answer has helped you, please indicate this)