Causes, risk factors, and complications of cardiogenic shock
The most common cause of cardiogenic shock is a heart attack, when the flow of blood through the arteries is restricted or blocked by a waxy substance called plaque. Other causes and risk factors of cardiogenic shock include:
- Pulmonary embolism (sudden blockage of an artery in the lung)
- Pericardial tamponade (fluid buildup around the heart, reducing its filling capacity)
- Sudden valvular regurgitation (damage to the valves allowing the backflow of blood)
- Myocarditis (inflammation of the heart)
- Endocarditis (infection of the heart valves)
- Rupture of the wall of the heart (due to increased pressure)
- Inability of heart muscle to work properly (or at all in some cases)
- Ventricular fibrillation (an arrhythmia in which the lower chambers fibrillate or quiver)
- Ventricular tachycardia (an arrhythmia where the ventricles beat too fast)
- Drug overdoses or poisoning that affects the heart’s ability to pump blood
- Breaking open (rupture) of the heart muscle due to damage from the heart attack
- Tear or rupture of the muscles or tendons that support the heart valves, especially the mitral valve
- Tear or rupture of the wall (septum) between the left and right ventricles (lower heart chambers)
- Bradycardia (very slow heart rhythm) or problem with the electrical system of the heart (heart block)
People who are older, have a history of heart failure or attacks, have diabetes or high blood pressure, and are female have a higher risk of developing cardiogenic shock.
What are the symptoms and diagnosis of cardiogenic shock?
Some symptoms of cardiogenic shock include rapid breathing, chest pain, severe shortness of breath, tachycardia (sudden rapid heartbeat), loss of consciousness, weak pulse, low blood pressure, pale skin, sweating, cold extremities, and oliguria (urinating less than normal or not at all). Other signs and symptoms include confusion and anxiety, fatigue, and even a coma if the shock is not treated and stopped quickly.
A cardiogenic shock diagnosis is usually performed in an emergency setting. In these situations, doctors will check for signs and symptoms of shock and perform certain tests to find the cause. These tests may include the following:
Measure blood pressure: People with cardiogenic shock have very low blood pressure.
Electrocardiogram (ECG): Records the electrical activity of the heart to find out if the muscle is damaged. If it is, or if there are electrical problems or fluid build-up around the heart, it will not conduct electrical impulses normally.
Chest X-ray: Allows your doctor to observe the size and shape of your heart and its blood vessels. It also helps the doctor see if there is fluid in your lungs.
Blood draws and tests: Conducted to check for organ damage, infection, and heart attack. Blood-oxygen levels can also be measured using these tests (arterial blood gas test).
Echocardiograms: Sound waves used in this test produce an image of your heart, which can help identify if your heart has been damaged by a heart attack.
Angiogram (cardiac catheterization): A dye in the form of a liquid is injected into your heart’s arteries through a long, thin tube that is inserted through an artery in your leg. The dye makes your arteries visible on an X-ray, showing if there are areas of blockage or narrowing.
Cardiac enzyme test: When heart cells die, they release enzymes into the blood known as markers or biomarkers. By measuring these markers, doctors can find out if your heart has been damaged.
Treatment options for cardiogenic shock
Treatment for cardiogenic shock focuses on minimizing the damage from the lack of oxygen to the heart muscle and other organs. Since diagnosis often occurs in an emergency, patients would be connected to a ventilator and would receive medications and fluid through an intravenous line in the arm. Some medications used include the following:
- Inotropic agents: Dopamine or norepinephrine are medications given to improve heart function until other treatments begin to work.
- Aspirin/Antiplatelet medication: Typically used by emergency medical workers to immediately reduce blood clotting and keep blood flowing through an artery even if it is narrowed.
- Thrombolytics: Also known as clot busters or fibrinolytisc, these drugs are given to help dissolve a blood clot that’s preventing blood from flowing to your heart. The sooner you receive this kind of medicine after a heart attack, the greater your chances of survival will be.
Medical procedures are also used to treat cardiogenic shock. Some treatments include:
- Angioplasty and stenting: A long, thin tube or catheter equipped with a special balloon is inserted through an artery in your leg to a blocked artery in your heart. Once there, the balloon is inflated briefly to open the blockage.
- Balloon pump: The doctor will insert a balloon pump in the main artery off of your heart, known as the aorta. The pump will inflate and deflate within the aorta, allowing for blood flow and taking some of the workload off your heart.
- Mechanical circulatory support: Newer methods than those mentioned above are being used to improve circulation and supply oxygen to the body. One of these new methods is known as extracorporeal membrane oxygenation (ECMO).
Surgery is the third form of treatment used to help those with cardiogenic shock. Here are some of the surgeries associated with this condition:
- Coronary artery bypass surgery: Sewing veins and arteries in place in a location beyond a blocked coronary artery. This procedure may be recommended after your heart has recovered from a heart attack, but is occasionally performed on an emergency basis.
- Surgery to repair a heart injury: If your heart has been torn in one of its chambers, or if you have a damaged heart valve, cardiogenic shock may occur. Surgery may correct the problem.
- Ventricular assist device: Implanted into the abdomen and attached to the heart to help it pump blood. This operation may extend and improve the lives of those with end-stage heart failure, who are waiting or are unable to have a heart transplant.
- Heart transplant: If the heart is so damaged that no other treatments work, a heart transplant may be the last option.
Prevention of cardiogenic shock
While there are treatments for cardiogenic shock, the condition is extremely serious. Preventing its root causes is key to ensuring that you may never suffer from cardiogenic shock. Some of these root causes include hypertension, obesity, smoking, and high cholesterol. For those with a previous history of heart attack, your doctor may prescribe medications that can help prevent you from having cardiogenic shock. Here are some important tips to help you prevent cardiogenic shock:
- Don’t smoke and avoid secondhand smoke. Several years after quitting smoking, your risk will reduce to the same level of a nonsmoker.
- Being overweight contributes to other risk factors for heart attack and cardiogenic shock, including high blood pressure, cardiovascular disease, and diabetes. If you lose just 10 points, you will lower your blood pressure and improve your cholesterol levels. Weight loss is an effective preventative solution.
- Limit your cholesterol and saturated fat intake to reduce your risk of heart disease. Trans fat should always be avoided.
- Limit added sugar and alcohol to avoid nutrient-poor calories and help you maintain a healthy weight.
- Regular exercise can lower your blood pressure, increase your level of high-density lipoprotein (HDL) cholesterol, and improve your blood vessel and heart health. Working up to 30 minutes of activity a day, even with light exercise like walking, jogging, bicycling, or swimming, can help you maintain a healthier heart.
Prognosis of cardiogenic shock
Cardiogenic shock is the leading cause of death after a heart attack, with rates as high as 70 to 90 percent without aggressive care. By observing hypotension, an absence of hypovolemia, and clinical signs of poor tissue perfusion, doctors can diagnose this condition quickly. Noticing the signs during a physical examination, doctors can recognize the condition and spring into action to provide treatment and solutions, but the sooner you are diagnosed, the more effective treatments will be. As with all health conditions and illnesses, it is important to live a healthy lifestyle to prevent a heart attack in the first place.
Also read: 10 foods to help prevent clogged arteries naturally