The primary cause of a massive heart attack or sudden cardiac arrest is a problem with the heart's electrical system which produces an abnormality in heart rhythm, according to Mayo Clinic. Cardiac arrest occurs when erratic, rapid electrical impulses prompt the ventricles to quiver versus pumping blood.
A massive heart attack does not normally strike in individuals with a healthy and normal heart unless an outside trigger such as illegal drugs, trauma or electrical shock occurs, explains Mayo Clinic. Additional factors that can lead to problems with the heart's electrical system that lead to a massive heart attack include high blood pressure, abnormal cholesterol, diabetes, abdominal obesity and stress, according to WebMD. Heart problems that can lead to a heart attack also include a smoking, sedentary lifestyle, or a diet that lacks vegetables and fruits.
Common symptoms of a heart attack include chest pain, difficulty breathing and upper body discomfort, according to the National Heart, Lung and Blood Institute. Some patients experience cold sweats, nausea, vomiting, sudden dizziness or unexplained fatigue. Symptoms of a massive heart attack can be intense and sudden and come and go in varying stages of intensity. Chest pain is the most common symptom of a massive heart attack.