Definition of Cardiogenic Shock
Cardiogenic shock is a rare medical condition where there is abrupt decrease in the ability of the heart to pump sufficient blood as required by the body. The most common cause of cardiogenic shock is severe heart attack. Cardiogenic shock can be fatal if it is not treated immediately. Prompt treatment can save about 50% of the patients' life who have cardiogenic shock.
Treatment comprises of medications like aspirin, super-aspirins, heparin and medical procures like angioplasty and stenting; and balloon pump insertion. Surgery comprises of coronary artery bypass surgery, heart pumps and heart transplantation as a last resort.
Causes of Cardiogenic Shock
A person experiences cardiogenic shock when his/her heart cannot pump sufficient blood for the entire body. Cardiogenic shock commonly occurs due to damage to the left ventricle, which is the heart's main pumping chamber, from decreased oxygen due to heart attack. Causes of a heart attack are blockage of the coronary arteries which supply the heart with oxygenated blood. With age, there is narrowing of the coronary arteries due to accumulation of cholesterol (plaques) in the arteries. This condition is known as atherosclerosis. When and if these plaques rupture, they form blood clot which hinders/blocks the blood within the artery leading to heart attack. This lack of oxygen-rich blood to the heart causes weakening of the heart muscle which ultimately results in a cardiogenic shock.
As mentioned above, heart attacks are the commonest cause for cardiogenic shock. Other conditions which can cause cardiogenic shock are: Myocarditis, endocarditis, drug over dosage, poisoning; all which can impact the heart's pumping ability. Cardiogenic shock can also occur as a result of damage to the heart's right ventricle; however, this is very rare.
Risk Factors for Cardiogenic Shock
- Having a previous history of heart failure/heart attack increases the risk of developing cardiogenic shock.
- Individuals who are above the age of 65 years are at an increased risk for developing cardiogenic shock.
- Coronary artery disease or blockages in multiple main arteries of the heart increases the risk of cardiogenic shock.
- Severe shortness of breath and rapid breathing.
- Tachycardia (rapid heartbeat).
- Mental alteration or confusion.
- Loss of consciousness.
- Weak/faint pulse.
- Pale, clammy skin and sweating.
- The hands or feet feel cold.
- Decreased urine output or no urine output.
Signs & Symptoms of Heart Attack Which Are The Major Cause Of Cardiogenic Shock
It is important to identify the signs & symptoms of a heart attack as that is the major cause of cardiogenic shock. Signs and symptoms of a heart attack include:
- Feeling of tightness, fullness, pressure, squeezing pain in the center of the chest. This feeling can last for some minutes.
- Pain radiates towards the shoulder, back, arm, teeth and jaw.
- Patient begins to have increasing episodes of chest pain.
- Continuous pain in the upper abdominal region.
- Shortness of breath.
- Patient starts sweating and has a feeling of impending disaster.
- Nausea and vomiting.
- Loss of consciousness.
If the patient seeks immediate medical attention upon experiencing these signs or symptoms, then chances of developing a cardiogenic shock greatly decreases.
Investigations for Cardiogenic Shock
- Physical examination & medical history.
- Blood pressure evaluation, as patients who are in a cardiogenic shock in shock often will be hypotensive (low blood pressure).
- Electrocardiogram (ECG) is done to diagnose a heart attack.
- Chest x-ray helps in assessing the size and shape of the heart and its blood vessels.
- Blood tests are done to find out if any damage has occurred to the kidneys or liver. Blood tests also help in looking for signs of a heart infection and heart attack.
- Arterial Blood Gas is a blood test done to determine the amount of oxygen present in the blood.
- Echocardiogram is a test which uses sound waves to generate an image of the heart. This will help in identifying the damaged area of the heart.
- Angiogram (coronary catheterization) is done to assess the blockage in the coronary arteries.
- Angioplasty can be done during an angiogram to widen the blocked area by placing a stent within the blocked artery in order to keep it open and to prevent re-narrowing in the future.
Treatment for Cardiogenic Shock
The treatment for cardiogenic shock focuses on repairing the heart muscle damage and also the damage to other organs which has occurred as a result of lack of oxygen.
- Emergency Life Support is mandatory for patients suffering from cardiogenic shock. In emergency life support, patient is given supplemental oxygen to breathe, so the damage to the muscles and organs is minimized. In severe cases, patient is also connected to a ventilator which is a breathing machine to help him/her breathe. Patient is given fluid and medications intravenously.
Medications For Treating Cardiogenic Shock
Medications for treating cardiogenic shock are given to improve the blood flow through the heart and to enhance the pumping ability of the heart. Medications for these purposes given in cardiogenic shock include:
- Aspirin is immediately given by the emergency medical personnel. Aspirin helps in cutting down the blood clotting and in keeping the blood flow going through the narrowed artery.
- Thrombolytics are medicines, which are also known as clot busters and they help in dissolving a blood clot, which is causing hindrance in the blood flow to the heart. Giving a thrombolytic drug as soon as the patient has had a heart attack increases the chances of survival and decreases the chances of damage to the heart.
- Super-aspirins are similar to aspirin and are given in the emergency room. They also help in preventing the formation of new clots.
- Blood-thinning medications, like heparin, also help in preventing the formation of dangerous clots.
- Inotropic agents, such as epinephrine or dopamine, help in improving as well as supporting the function of the heart.
Medical Procedures For Treating Cardiogenic Shock
Medical procedures for treating cardiogenic shock focus on reestablishing blood flow through the heart and these include:
- Angioplasty & Stenting: Emergency angioplasty is done to open the blocked coronary arteries, which in turn will restore the blood flow to the heart. As soon as the blood flow is restored, the symptoms of cardiogenic shock will improve. This procedure comprises of inserting a catheter, which is a long, thin tube, through an artery (often in the leg) to the blocked artery in the heart. This catheter is fitted with a special balloon, which is briefly inflated when it is in the blocked region to widen/open the blocked coronary artery. During this time, a metal mesh stent can be inserted into the artery in order to keep the artery wide/open for a longer period of time and to restore the blood flow to the heart. In majority of the patients, a stent which is coated with a slow-releasing medication is used to keep the artery open.
- Insertion of a Balloon Pump can be done depending on the patient's condition. The balloon pump is inserted in the aorta, which is the main artery of the heart. This balloon pump mimics the pumping action of the heart by inflating and deflating and this helps in the blood flow through the heart.
Surgical Procedures For Treating Cardiogenic Shock
- Coronary artery bypass surgery comprises of sewing arteries or veins at a place beyond the blocked coronary artery. This helps in restoring the blood flow to the heart.
- Surgery to repair any damage/ injury to the heart, such as a tear in a heart chamber or damage to the heart valve can be done if needed. All this can also cause cardiogenic shock. So, surgery can be done to correct these problems.
- Heart pumps are mechanical devices and are known as ventricular assist devices (VADs). These devices are placed in the abdomen and are connected to the weakened heart in order to help it pump. Implanted heart pumps help in improving, as well as extending the patient's life, some of them who have end-stage heart failure and are not suitable candidates for heart transplantation.
- Heart transplant is needed if the heart is extremely damaged and is beyond any repair or any treatment. A heart transplant is often used as a last resort for treatment of cardiogenic shock.
Prevention of Cardiogenic Shock
Cardiogenic shock can be prevented by preventing a heart attack from happening. Patient should follow the same lifestyle changes which are for treating any heart disease to prevent heart attack. The lifestyle modifications are:
- Controlling hypertension or high blood pressure is very important to decrease the chances of a heart attack and cardiogenic shock. To do this, patient should exercise regularly, manage his/her stress, maintain a healthy weight, restrict sodium and alcohol intake etc.
- Quitting smoking if you are a smoker decreases the risk of having a heart attack.
- Obesity or being overweight adds on to other risk factors for heart attack and cardiogenic shock. So, it is important to lose weight and maintain a stable and healthy weight by eating healthy and exercising daily.
- Decrease the consumption of cholesterol and saturated fat in your diet, as it increases the risk of developing heart disease. If dietary changes alone are not sufficient to keep the cholesterol under control, then cholesterol-lowering medications can be prescribed.
- Exercising regularly cuts down the risk of having a heart attack by lowering and maintaining the blood pressure, increasing HDL level and also improves the overall health of the heart and blood vessels.