Although many people think that the terms ‘heart attack' and ‘cardiac arrest' mean the same thing, this is not true. They are different occurrences though they both affect the heart. They have different risk factors, outcomes and treatment options.
Before looking at the differences, it is important to understand that the heart works by contracting and relaxing its muscles. The heart has muscles in all its four chambers which contract and expand depending on the electric charge reaching them. The electric charge is produced by the inter-ventricular node on the junction of the two lower chambers (ventricles) and the sino-atrial node located on the right atrium (upper chamber).
Cardiac arrest occurs when there is a problem with the transmission of the electrical signals. The most common problem resulting in cardiac arrest is ventricular fibrillation in which the ventricles develop and sudden irregular rhythm causes them to quiver instead of contracting. They are therefore become incapable of pumping blood effectively. As a result, the heart is unable to supply the brain and other body parts with nutrients, oxygen and other materials carried in blood.
A heart attack, on the other hand, occurs due to a blockage in the artery that supplies the heart. With such a blockage, the heart is not supplied with enough blood and is therefore not well-nourished. This causes the heart’s muscle to die. This is majorly due to coronary heart disease which causes plaques to develop in the arteries that may form a clot that can lead to the blockage resulting in a heart attack.
When it comes to a heart attack, the signs often start slowly and persist for hours, days or even weeks before the heart stops working. On the other hand, the effects of cardiac arrest are always sudden and characterized by a lack of pulse and loss of consciousness. A cardiac arrest can occur due to a heart attack, but a heart attack cannot occur due to a cardiac arrest.
The symptoms of a heart attack include tightness in the centre of the chest. The pain is often spreading to other areas like the left arm, neck, jaw and abdomen. Coughing, wheezing, sneezing, shortness of breath and palpitations are also the common symptoms. On the other hand, the symptoms of cardiac arrest include sudden loss of consciousness, lack of breath and lack of pulse.
As for the intervention, cardiac arrest needs to be treated in a matter of minutes for it to be reversible. An automated defibrillator will usually be used. In contrast, a heart attack may be reversed up to as long as an hour after it has occurred. However, both issues are emergencies and need to be handled as soon as possible.