Cardiogenic Shock

Cardiogenic shock is a life-threatening emergency where your heart suddenly cannot pump enough blood to meet your body’s needs. Without enough oxygen-rich blood reaching vital organs, this condition can quickly lead to organ failure and death if not treated immediately.

Table of contents

• What is cardiogenic shock?
• What causes this condition?
• Warning signs and symptoms
• How doctors identify cardiogenic shock
• Treatment approaches
• Recovery and ongoing care
• Prevention strategies

What is cardiogenic shock?

Cardiogenic shock, also known as cardiac shock, happens when your heart cannot pump enough blood and oxygen to the brain and other vital organs^[1]. This is a medical emergency that requires immediate treatment. Without oxygen-rich blood reaching vital organs, your blood pressure drops, and your pulse slows^[5].

cardiac shock

This condition is relatively rare, affecting approximately 40,000 to 50,000 people per year in the United States^[4]. Despite being uncommon, cardiogenic shock is very serious. When treated quickly in a hospital, about half of people who develop this condition survive^[13]. However, the 30-day mortality rate for cardiogenic shock after a heart attack is 40%, with a 1-year mortality rate of 50%^[2].

Doctors may categorize cardiogenic shock into different stages, ranging from being at risk to being very sick. These stages are:

• At risk (A): Heart attack or heart failure (when the heart can’t pump enough blood to meet the body’s needs), but no signs of shock
• Beginning (B): Low blood pressure or heart rate
• Classic (C): Need for medicine or devices to help get blood to organs
• Deteriorating (D): No response to medicines or devices for 30 minutes and getting worse
• Extremis (E): Cardiac arrest that needs CPR, ventilator and defibrillator^[4]

What causes this condition?

The most common cause of cardiogenic shock is a severe heart attack. A heart attack (also called myocardial infarction) occurs when there is a lack of oxygen-rich blood flow to the heart muscle, leading to damage to the pumping chambers of the heart^[1]. Cardiogenic shock complicates about 5 to 10% of all heart attacks^[2]. However, not everyone who has a heart attack develops cardiogenic shock^[1].

Various forms of cardiac problems can lead to cardiogenic shock. Other conditions that may cause this emergency include:

• Inflammation in your heart muscle, called myocarditis
• An infection in your heart valves, known as endocarditis
• Heart failure, which happens when the heart can’t pump enough blood to meet the body’s needs
• An abnormal heart rhythm, called an arrhythmia
• Too much fluid or blood around your heart, a condition called cardiac tamponade
• A blood clot that suddenly blocks a blood vessel in your lung, called a pulmonary embolism
• A heart valve problem, such as torn muscles supporting your valve or a replacement valve not working right
• Damage to the wall of tissue between the left and right ventricles of your heart
• Injury to your chest^[4]

Other causes include damage from certain medications (such as doxorubicin), medication overdose (beta or calcium channel blockers), metabolic problems like acidosis, and abnormal levels of calcium or phosphate in the blood^[3].

Several factors can increase your risk of developing cardiogenic shock. Risk factors include:

• Being 75 years or older
• Previous heart attack
• Heart failure
• Coronary artery disease (narrowing of the arteries that supply blood to the heart)
• High blood pressure
• High cholesterol
• Diabetes
• Use of tobacco products
• Being overweight or obese
• Previous coronary artery bypass surgery
• Lack of physical activity^[4]

This condition happens more often in females^[4]. For people who have had a heart attack that raised a specific part of the heart’s electrical signal (called ST-elevation), additional risk factors for developing cardiogenic shock include age more than 70 years, systolic blood pressure less than 120 mmHg, rapid or slow heart rate, and a long time between when symptoms started and when treatment began^[3].

Warning signs and symptoms

Cardiogenic shock causes several noticeable symptoms that require immediate medical attention. Common symptoms include:

• Very fast breathing
• Severe shortness of breath
• Very fast heartbeat or weak pulse
• Low blood pressure
• Sweating
• Cold hands or feet
• Pale skin or loss of skin color
• Urinating less than usual or not at all
• Confusion or not being aware or alert to surroundings
• Fainting or loss of consciousness
• Fatigue^[1]

Because cardiogenic shock usually occurs in people who are having a severe heart attack, it is crucial to know the signs and symptoms of a heart attack. These include:

• Chest pain that may feel like pressure, tightness, pain, squeezing or aching
• Pain or discomfort that spreads to the shoulder, arm, back, neck, jaw, teeth or sometimes the upper belly
• Cold sweats
• Fatigue
• Heartburn, also called indigestion
• Lightheadedness or sudden dizziness
• Nausea and vomiting
• Shortness of breath^[1]

A heart attack usually causes chest pain that lasts more than 15 minutes. The chest pain may be mild or severe. Some people don’t have any chest pain or pressure^[1]. Symptoms may be less obvious in some people, especially for women. For example, heart attack symptoms may include nausea or a brief or sharp pain felt in the neck, arm or back^[1].

Call 911 or your local emergency number immediately for anyone who has symptoms of heart attack or cardiogenic shock. Getting help right away may improve the chance of survival and reduce damage to the heart^[1].

How doctors identify cardiogenic shock

Cardiogenic shock is usually diagnosed in an emergency setting^[8]. Your healthcare provider will ask about your medical history, including how you’re feeling that day or recently^[4]. During a physical exam, they may find these signs of cardiogenic shock:

• A weak pulse
• Skin that feels cold and clammy
• Low blood pressure (most often less than 90 mmHg systolic)
• An abnormal heart rhythm or heart murmur they can hear through a stethoscope^[4]

Several tests can help doctors confirm if you have cardiogenic shock and find its cause:

Blood pressure check: Cardiogenic shock causes very low blood pressure. In general, low blood pressure is a reading lower than 90/60 mm Hg. However, a low blood pressure reading alone is not enough to diagnose cardiogenic shock^[8].

Electrocardiogram (ECG or EKG): This quick and simple test shows how the heart is beating. It can tell if a person is having a heart attack. Sticky patches with sensors go on the chest and sometimes the arms or legs. A damaged heart muscle or fluid buildup around the heart may change the pattern of the heartbeat^[8].

Chest X-ray: A chest X-ray shows the size and shape of the heart and lungs. It also can show if there’s fluid in the lungs, which is a sign that the heart isn’t pumping well^[8].

Blood tests: Blood tests can check for signs of organ damage, infection and heart attack. An arterial blood gas test might be done to measure oxygen in the blood^[8]. These tests can also reveal organ function and detect substances that may indicate heart stress or damage^[4].

Echocardiogram: Sound waves create pictures of the beating heart. This test can see how blood flows through the heart and heart valves. It can tell if there’s damage from a heart attack^[8]. This ultrasound test evaluates the function of your heart’s pumping chambers and valves^[7].

Cardiac catheterization: This test looks for blocked or narrowed arteries. A doctor places a long, thin tube called a catheter through an artery, usually in the groin area or wrist. The doctor moves the tube up to the heart. Dye flows through the tube. It helps the arteries show up more clearly on images made during the test. The dye part of the test is called a coronary angiogram^[8]. This test can also check how much blood your heart is pumping^[4].

To diagnose cardiogenic shock, a catheter (tube) may be placed in the lung artery in a procedure called right heart catheterization. Tests may show that blood is backing up into the lungs and the heart is not pumping well^[6].

Treatment approaches

Cardiogenic shock is a medical emergency that requires immediate treatment in a hospital, most often in the Intensive Care Unit or Coronary Care Unit^[6]. The goal of treatment is to restore blood pressure and heart function as quickly as possible to minimize damage to your heart and other organs^[13].

Treatment often begins in an emergency setting and may include enriched oxygen in a tube or mask, breathing assistance with a ventilator, and fluids and medications given through a vein to boost blood pressure or heart function^[10]. You may also receive pain medicine, oxygen, and fluids, blood, and blood products through a vein^[6].

Medications

Medicine can help increase blood flow and protect against organ damage. Some medicines treat the underlying cause of cardiogenic shock, which is usually a heart attack^[9]. You may need medicines to increase blood pressure and improve heart function, including:

• Dobutamine
• Dopamine
• Epinephrine
• Levosimendan
• Milrinone
• Norepinephrine
• Vasopressin^[6]

These medicines may help in the short-term. They are not often used for a long time^[6]. Medicines that increase blood pressure and blood flow out of the heart are called vasopressors and inotropes^[9].

Other medications may include:

• Medicines to restore a regular heartbeat, called anti-arrhythmia medicines
• Blood thinners or antiplatelet medicines that can dissolve blood clots and reduce platelets (cell fragments in blood that help form clots) that may be blocking the coronary arteries
• Thrombolytic drugs to dissolve coronary artery clots (sometimes called “clot-busting” drugs such as tPA)
• Anticlotting agents to prevent new clots (such as aspirin, clopidogrel, heparin)^[9][10]

Medical procedures

Some medical procedures may be done right away to restore blood flow within your heart and throughout your body, preventing organ damage:

Coronary artery bypass grafting (CABG): Sometimes called coronary artery bypass surgery or just bypass surgery, this procedure improves poor blood flow to the heart muscle. The surgery creates new paths for blood to flow to the heart when the coronary arteries (arteries that supply blood to the heart itself) are narrowed or blocked^[9].

Balloon angioplasty: This procedure is used to open blocked coronary vessels. During this minimally invasive procedure, a catheter (thin, flexible tube) is guided into the blocked artery and a tiny balloon is inflated to clear the way so that blood flow is restored. In some cases, a stent (small mesh tube) is inserted to keep the artery open^[10].

Cardiac catheterization with coronary angioplasty and stent placement may be performed to open blocked arteries^[6]. If cardiogenic shock is due to a heart attack, attempts to open the heart’s arteries may help^[2].

Heart surgery: Options may include coronary artery bypass surgery, heart valve replacement, or placement of a left ventricular assist device (a mechanical pump that helps the heart pump blood)^[6].

Medical devices and mechanical support

When a heart rhythm problem is serious, urgent treatment may be needed to restore a normal heart rhythm. This may include:

• Electrical “shock” therapy (defibrillation or cardioversion)
• Implanting a temporary pacemaker (a device that helps control heart rhythm)
• Medicines given through a vein^[6]

When medications fail, more advanced options such as mechanical support devices may be used^[2]. These temporary support devices may be used to help restore proper blood flow:

Intra-aortic balloon pump: This device is placed in the aortic artery (the main artery of your heart) and provides an extra push to help move blood coming out of your heart^[7]. This treatment can help the heart work better^[6].

Other short-term devices that are used to treat cardiogenic shock include Impella, Tandem heart and extra corporeal membrane oxygenation (ECMO)^[10]. A ventricular assist device or other mechanical support may be needed^[6].

If your heart does not respond well enough to other treatments, your doctor may recommend a heart transplant. While you wait for a heart transplant, you may need a total artificial heart if you had cardiogenic shock affecting both the left and right ventricles of your heart^[15].

Recovery and ongoing care

As you recover from cardiogenic shock, it is important to follow your treatment plan and adopt healthy lifestyle changes to prevent another event^[15]. You also may need follow-up treatment or support for implanted devices or complications of cardiogenic shock, including organ failure^[15].

Your doctor may recommend regular follow-up visits to monitor your condition and any medical device that supports your health after cardiogenic shock. If you have an implanted medical device to help your heart work better, your doctor will check to make sure that the device is working properly. Your doctor will then give you instructions on what to do if the device gives a warning that it is not working correctly^[15].

Tell your doctor if you have any new symptoms, if your symptoms worsen, or if you have problems with other medical conditions that may increase your risk of heart events^[15].

Complications from cardiogenic shock may include damage to organs like your brain, liver and kidneys. You can have abnormal heart rhythms that lead to cardiac arrest. Stroke is another possible complication^[4]. Care should also be directed to any other organs that are affected by this lack of blood flow (for example, dialysis for the kidneys, mechanical ventilation for lung dysfunction)^[2].

Prevention strategies

As with other heart conditions, the best way to prevent cardiogenic shock is to practice good heart health—a healthy diet, exercise and quitting smoking^[14].

Because cardiogenic shock is usually a serious complication of coronary heart disease, your healthcare provider may recommend a heart-healthy lifestyle. Practice heart-healthy eating, with the DASH (Dietary Approaches to Stop Hypertension) eating plan. A heart-healthy eating plan includes fruits, vegetables, and whole grains and limits saturated fats, sodium (salt), added sugars, and alcohol^[15].

Be physically active. Regular physical activity can help manage coronary heart disease risk factors^[15].

You can lower your risk by managing risk factors that you can change^[4]. This includes:

• Managing high blood pressure
• Controlling high cholesterol
• Managing diabetes
• Maintaining a healthy weight
• Stopping tobacco use
• Being physically active

If you have any questions about preventing cardiogenic shock or maintaining heart health, talk to your healthcare provider^[14].