Eli5: what is the difference between a heart attack and a cardiac arrest?
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BSN student here! An analogy I like to use for the heart is to think of it as a car.
A car has both mechanical and electrical components that need to be in working order for the car to function, and you need gas for the engine to work. So for example even if you have a full tank of gas, if you have an electrical issue (say your alternator is broken), your car won’t start. If your electrical is fine but you run out of gas, well your car isn’t going anywhere either. If you have a huge air bubble in your gas line, your car may sputter out for a second as it’s deprived momentarily of gas but may continue going afterwards. Or it may just fuck your shit up completely.
Your heart function is the same. There are mechanical and electrical functions that work together. Your brain sends electrical signals to the heart that stimulate the mechanical parts (the heart muscle, which is the “engine”) to squeeze and pump the blood (gas) through the body (also delivering the oxygen rich blood to the tissues of the heart much like a car injects fuel into an engine).
Now let’s think back the the air bubble in the line. If you get an air bubble or clot or blockage of some sort in the “fuel line” (aka the vessel delivering that blood, or “fuel”, to the heart) you cut off the oxygen supply and those tissues infarct (die from lack of oxygen). They can no longer squeeze. This is called a myocardial infarction (more commonly known as a heart attack). It’s an injury to the mechanical part of your heart (the muscle). This MAY lead to cardiac arrest (your car stopping working all together), but may not. It depends on the severity is the damage.
For cardiac arrest, think about it like your car rolling to a dead stop as you’re driving it. Maybe you have had a history of mechanical issues (heart attack, heart disease, chronic high stress, etc) that has led you here. The engine has stopped running and so your electrical pieces no longer have an energy source to keep going (heart not pumping = no oxygen being delivered to brain = bye bye to everything else). Maybe you were involved in a crash (blunt force trauma) that damaged the car so severely it can’t function. Maybe you just bought a lemon that didn’t have the wiring put in correctly and therefore was bound to fail eventually. Either way your car has stopped driving (heart has stopped beating) completely.
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