Cardiac arrest and heart attack are two different entities. However both are serious medical emergencies. A Lot of people used to confuse with the meaning of cardiac arrest and heart attack.
Cardiac arrest is also known as circulatory arrest. In cardiac arrest the blood does not pump out of the heart and thus arrest the blood circulation. Heart attack (myocardial infarction) is a cause of cardiac arrest. In heart attack the blood supply to the heart muscles is impaired. This results in lack of oxygen supply to the cardiac muscles. Heart muscle will die if there are no supply of oxygen and fuel for it’s function. Usually heart attack is caused by block in the coronary arteries. Coronary arteries are the vessels that supply the blood to the heart. High cholesterol is a major risk factor for heart attack. Cholesterol deposition in the vessel will block the blood supply. The family history of heart attack is associated with increased risk of developing heart attack. Diabetes mellitus, smoking, obesity and lack of exercise also increase the risk of heart attack.
Heart attack can be mild to severe. Depending on the amount of the cardiac muscle and the site of the muscle death, the out come may vary. If the heart attack is severe, immediate death results. Myocardial infarction (heart attack) presents as severe tightening pain in the chest. It may be associated with sweating. If the heart attack is severe it causes cardiac arrest.
As muscles of the heart is damaged by heart attack, measuring the troponin level (marker) in the blood will help to diagnose it. The ECG changes will show if there is ischemia (lack of blood supply) to the muscles.
Mild attack will not kill the person. However there are more risk of developing further attack. Cardiac arrest is caused by various conditions. Myocardial infarction is one of the major cause. Lack of oxygen supply (ex drowning), severe cold (hypothermia), inadequate blood in the body (hypo volumia), increase acidity in the blood, increased or decreased potassium level in the blood, the drugs poison to the heart, failure of respiration, severe electricution are some of the causes for cardiac arrest.
Usually cardiac arrest is confirmed by the absence of carotid artery pulse. The cardiac arrest can be reversed if it is diagnosed early and treated appropriatly. The CPR (cardio pulmonary resuscitation) will reverse the arrest if other causes of the cardiac arrest are corrected. CPR can be done by a person who is trained for CPR.
Both cardiac arrest and heart attack result in fatal outcome. Both are sudden onset.
Cardiac arrest may be reversible, but the heart attack destroy the muscles and it is not reversible.
Severe heart attack may cause cardiac arrest.
Heart attack usually occurs in the people with high cholesterol or with other risk factors.
Heart attack occurs in older age, however cardiac arrest can occur at any age.