Hi, Thanks for using Healthcaremagic, After going through your history, he had a episode of Supraventricular Tachycardia, I presume this is reverted back to normal and he is given some drugs to prevent recurrence. Vomiting blood is Hematemesis which can have many causes and best way to know the cause is to do a Gastroscopy, he should plan for it if not already done. Other differentials are any blood due to analgesics, or alcohol induced injury to liver. Sometimes blood is coming from throat or lungs that must be searched and examined and if required X ray chest may also be done to find out source. Any type of bleeding diathesis is another possibility so just visit the Physician and I am sure once cause is detected he can be treated . Please avoid alcohol and Analgesics in the meantime. Hope this helps. Take care. Good Luck. Dr.Akhilesh Dubey M.D.