a. Prepare for cardiac defibrillation.

Step-by-step explanation

The patient in this case is having a heart attack. The most common heart attack symptom is chest pain (angina) or tightness. Since the patient became unconscious (fell to the floor), the first and the most important thing to do in this situation is to prepare for cardiac defibrillation. When someone suffers a cardiac arrest, they become unconscious, stop breathing, and have no pulse. When this happens, the heart must be started again as soon as possible, so the brain and other vital organs can get the oxygen they need. After three minutes without oxygen, the brain cells start to die and this can lead to permanent neurological consequences. If this happens, the patient may become brain dead even after successfully restarting his heart. A cardiac defibrillator sends an electrical current or shock to the heart to try to start it pumping again. The person will then be transported to a coronary care or intensive care unit (ICU), where they will receive further treatment.