What happens to the brain during a heart attack and a cardiac arrest? Neurosurgeon explains the difference and risks

From reduced blood flow to brain damage, here’s what happens to the brain during a heart attack or cardiac arrest.

The brain cannot survive without oxygen, and honestly, it can't last long without it. It is one of the most oxygen-dependent organs we have. Even though it makes up only about 2 percent of total body weight, it uses roughly 20 percent of the body's oxygen supply. Other organs can manage a little because they carry small reserves, yet the brain is different. It has very limited storage, so when circulation is cut off even briefly, it becomes extremely fragile. In an interview with HT Lifestyle, Dr Sumeet Pawar, MBBS, DNB (Neurosurgery), minimally invasive brain and spine surgeon, explains what happens when blood flow to the brain stops.

Heart attack and cardiac arrest are not the same

Dr Sumeet highlighted that a heart attack and a cardiac arrest are basically not the same thing, even though people mix them up a lot. A heart attack happens when the blood supply to the heart muscle gets blocked, and still, the heart often keeps beating, at least for a while. Cardiac arrest, on the other hand, is when the heart suddenly stops pumping blood in a useful way. In cardiac arrest, the blood flow to the brain goes away almost right away, and that turns it into a real life-threatening situation.

A heart attack and a cardiac arrest are basically not the same thing, even though people mix them up a lot. (Pexel)

What goes on inside the brain?

Dr Sumeet said, “When oxygen-rich blood no longer makes it to the brain, the cells start misfiring within seconds. Usually, the person goes unconscious after 10 to 20 seconds.” If circulation isn't brought back within 3 to 5 minutes, irreversible damage to the brain tissue can begin. The longer the brain sits without oxygen, the higher the chance of lasting neurological harm, such as memory trouble, problems with speech, movement issues, or possibly brain death.

Why does every minute matter so much?

According to Dr Sumeet, doing CPR right away helps keep a small, but still critical, trickle of blood moving to the brain until further medical care actually arrives. Early defibrillation, when it’s appropriate, can boost the odds of survival quite a lot. It also tends to lower the risk of long-term brain injury.

Doing CPR right away helps keep a small, but still critical. (Pexel)

Recovery depends on acting fast

People who get through a cardiac arrest might return to normal; other patients—depending on how long the oxygen was cut off—can need neurological rehabilitation. Spot it early, call for emergency help immediately, and then follow a structured rehab plan; all of that matters for better results.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.