In case a person is having a cardiac arrest or heart attack, then there are only a few minutes left for quick action before it leads to permanent damage to the myocardial tissues. One must be ready to perform CPR (cardiopulmonary resuscitation) and artificial respiration (mouth to mouth resuscitation) effectively if required. In case a person is unconscious then you should take a look at his chest to observe its rise or fall and make out if the patient is breathing. Also, you need to check if the patient has a pulse by placing two fingers on one side of the person’s voice box to observe the carotid pulse.
If the patient has a pulse but he is not breathing then you should place finger inside his mouth to see if there is anything that is blocking the windpipe and remove any objects. You should take proper initiative for calling for help immediately. If needed, you should provide resuscitation until the patient starts breathing or till the arrival of ambulance.
You should make the person sit down and allows him to rest and keep calm. It is better to loosen any tight clothing and ask if the person has been administered with any chest pain medication. You can place a nitroglycerin under the tongue of person so that it dissolves directly into blood stream. If the patient is not responding at all the make an immediate call to local emergency number and begin CPR.
You should not leave the person unattended and alone. You should encourage the person to tell more of symptoms if he feels comfortable talking to you. You should never ignore to call for emergency help even if the person seems to recover little. You should not wait for the symptoms to go away. You should contact a Medical Professional in case a child or adult is not responsive or breathing even after giving CPR.