Cardiogenic shock is a state in which a weakened heart isn't able to pump enough blood to meet the body's needs. It is a medical emergency and is fatal if not treated right away. The most common cause of cardiogenic shock is damage to the heart muscle from a severe heart attack.
Not everyone who has a heart attack develops cardiogenic shock. In fact, less than 10 percent of people who have a heart attack develop it. But when cardiogenic shock does occur, it's very dangerous. For people who die from a heart attack in a hospital, cardiogenic shock is the most common cause.
What is shock?
The medical term "shock" refers to a state in which not enough blood and oxygen reach important organs in the body, such as the brain and kidneys. In a state of shock, a person's blood pressure is very low.
Shock can have a number of different causes. Cardiogenic shock is only one cause of shock. Other causes of shock include:
When a person is in shock (from any cause), not enough blood or oxygen is reaching the body's organs. If shock lasts more than several minutes, the lack of oxygen to the organs starts to damage them. If shock isn't treated quickly, the organ damage can become permanent, and the person can die.
Some of the signs and symptoms of shock include:
If you suspect that you or someone with you is in shock, call 911 (or, outside the US, your own country's emergency phone number) and get emergency treatment right away. Prompt treatment can help prevent or limit lasting damage to the brain and other organs and can prevent death.
In the past, almost no one survived cardiogenic shock. Now, thanks to improved treatments, around 50 percent of people who go into cardiogenic shock survive.
The reason more people are able to survive cardiogenic shock is because of treatments (medicines and devices) that restore blood flow to the heart and help the heart pump better. In some cases, devices that take over the pumping function of the heart are used. Implanting these devices requires major surgery.
What causes cardiogenic shock?
Cardiogenic shock happens when the heart can't pump enough blood to the
body. This mostly occurs when the left ventricle of the heart isn't working because the muscle isn't getting enough blood
or oxygen due to an ongoing heart attack. The weakened heart muscle can't
pump enough oxygen-rich blood to the rest of the body.
In about 3 percent of the cases of cardiogenic shock, the right ventricle isn't working. This means the heart can't effectively pump blood to the lungs, where the blood picks up oxygen to bring back to the heart and the rest of the body.
When the heart isn't pumping enough blood to the rest of the body, organs don't get enough oxygen and can be damaged. Some of the things that might happen include the following.
- When the kidneys aren't working right, the levels of important chemicals in the body change. This may cause the heart and other muscles to become even weaker, limiting blood flow even more.
- When the liver isn't working right, the body stops making proteins that cause the blood to clot. This can lead to more bleeding if the shock is due to blood loss.
How well the brain, kidneys, and other organs recover depends on how long a person is in shock. The shorter the time in shock, the less damage to the organs. This is another reason why it's so important to get emergency treatment right away.
The underlying causes of cardiogenic shock are conditions that weaken the heart and make it unable to pump enough blood and oxygen to the body.
These conditions include:
- Ventricular septal rupture. This is when the wall between the two ventricles breaks down because cells in part of the wall have died due to a heart attack. If the ventricles aren't separated, they can't pump properly.
- Papillary muscle infarction or rupture. This is when the muscles that help anchor the heart valves stop working or break because their blood supply is cut off due to a heart attack. When this happens, blood doesn't flow in the right way between the different chambers of the heart, and they can't pump properly.
- Myocarditis, or inflammation of the heart muscle.
- Arrhythmias, or problems with the speed or rhythm of the heartbeat.
- Pericardial tamponade, or too much fluid or blood around the heart. The fluid squeezes the heart muscle so it can't pump properly.
Who is at risk for cardiogenic shock?
The most common risk factor for cardiogenic shock is having a heart attack.
If you've had a heart attack, the following factors can further increase your risk for cardiogenic shock:
What are the signs and symptoms of cardiogenic shock?
A lack of blood and oxygen reaching the brain, kidneys, skin, and other parts of the body causes the symptoms of cardiogenic shock.
The signs and symptoms of cardiogenic shock include:
If you or someone with you is having these signs and symptoms, call right away for emergency treatment. Prompt treatment can help prevent or limit lasting damage to the heart and other organs and can prevent sudden death.
How is cardiogenic shock diagnosed?
The first step in diagnosing cardiogenic shock is to identify that a person is in shock. At that point, emergency treatment should be started.
Once emergency treatment is started, doctors can look for the specific cause of the shock. If the reason for the shock is that the heart isn't pumping strongly enough, then the diagnosis is cardiogenic shock.
Tests that are useful in diagnosing cardiogenic shock include:
Certain blood tests also are used to diagnose cardiogenic shock, including:
How is cardiogenic shock treated?
Cardiogenic shock is life threatening and requires emergency medical treatment. In most cases, cardiogenic shock is diagnosed after a person has been admitted to the hospital for a heart attack. If the person isn't already in the hospital, emergency treatment can start as soon as medical personnel arrive.
The goals of emergency treatment for cardiogenic shock are first to treat the shock and then to treat the underlying cause or causes of the shock.
Sometimes both the shock and its cause are treated at the same time. For example, doctors may quickly open a blocked blood vessel that's causing damage to the heart. Often, opening the blood vessel can get the patient out of shock with little or no additional treatment.
Emergency life support
Emergency life support treatment is required for any type of shock. This treatment helps get blood and oxygen flowing to the brain, kidneys, and other organs. Restoring blood flow to the organs is essential to keep the patient alive and to try to prevent long-term damage to the organs. Emergency life support treatment includes:
During and after emergency life support treatment, doctors try to find out what is causing the shock. If the reason for the shock is that the heart isn't pumping strongly enough, then the diagnosis is cardiogenic shock.
Depending on what is causing the cardiogenic shock, treatment may include medicines to:
Medical devices and procedures
In addition to medicines, there are medical devices that can help the heart pump and improve blood flow. The devices most commonly used to treat cardiogenic shock include:
Sometimes medicine and medical devices aren't enough to treat cardiogenic shock. Surgery can restore blood flow to the heart and the rest of the body and repair damage to the heart. Surgery can help keep a patient alive while recovering from shock and improve the chances for long-term survival.
The types of surgery used to treat underlying causes of cardiogenic shock include:
How can cardiogenic shock be prevented?
The best way to prevent cardiogenic shock is to do as much as you can to lower your risk for heart disease and prevent a heart attack.
If you have a heart attack, you should get immediate treatment to try to prevent cardiogenic shock and other possible complications.