Cardiogenic shock is the most common cause of death in people who suffer from heart attacks. Read and learn about the causes, symptoms, diagnosis and treatment of this potentially life-threatening condition.
Cardiogenic shock Definition
It is a condition caused by inability of a weakening heart to pump enough blood to satisfy the requirements of the body. The failure of the heart to pump blood leads to lower cardiac output. Despite enough intravascular volume, the various organs and tissues suffer from hypoxia and acute hypoperfusion.
The condition is found to develop in 5-10% patients with acute MI (Myocardial Infarction).Picture 1 – Cardiogenic shock Image (as seen in ER)
Cardiogenic shock Symptoms
Some of the primary symptoms of this condition include:
- Coldness in hands and feet
- Confusion or lack of alertness
- Decrease or absence of urine output
- Pale skin
- Weak pulse
- Rapid breathing
- Loss of consciousness
- Sudden and ongoing rapid heartbeat
In patients of acute myocardial infarction (MI), Cardiogenic shock typically gives rise to discomforting symptoms like:
- Chest pain
- Confusion or mental disorientation
- Dyspnoea (Air hunger or shortness of breath)
- Profuse sweating
- Nausea and vomiting
Patients may also suffer from Syncope, or loss of consciousness due to lack of proper blood supply to the brain. In many cases, patients suffer from Pulmonary edema due to accumulation of fluid in their lungs. This can make them sweat profusely and suffer from breathing problems. Some patients may also cough up blood.
Cardiogenic shock Causes
The condition can be caused due to various factors, such as:
- Myocardial infarction
- Rupture of the heart
- Pulmonary embolism
- Pericardial tamponade
- Valve disorders
The condition most arises commonly due to acute heart complications, many of which occur after or at the time of a heart attack (Myocardial infarction). Heart attack results in lack of oxygen which causes damage to the left ventricle, the main pumping chamber of the heart.
Cardiogenic shock Diagnosis
This condition is viewed as a medical crisis and hence, determined in an emergency setting. Doctors usually look for typical signs and symptoms of this disorder, such as:
- Pale, cold skin
- Distension of veins in the neck
- Mental confusion
- Reduced heart sounds
This is followed by additional tests to determine the actual cause of the condition. This can be done with the aid of diagnostic tests like:
It is the first test conducted to diagnose a heart attack. The test records the electrical impulses of the heart and displays them as waves on a monitor or prints them on paper. ECG tests are able to predict a heart attack by determining abnormalities in the electrical activity of the heart.
Blood pressure measurement
Very low blood pressure level in a person can indicate Cardiogenic shock.
Analysis of blood can help detect damages in liver or kidney, detect symptoms of a cardiac infection or determine a previous heart attack. A type of blood examination, known as Arterial Blood Gas, may also be performed to detect the amount of oxygen present in the bloodstream.
An X-ray imaging of the heart helps doctors determine its shape and size as also its blood vessels.
Coronary catheterization (Angiogram)
A liquid dye is injected into the cardiac arteries to make them visible on X-ray images. The dye fills the arteries, thus showing the areas where blockages have occurred. Angiogram is extremely helpful in detecting blockage or narrowing of the cardiac arteries.
The test involves use of audio waves to create an image of the heart and detect whether a particular section has been damaged. An instrument known as transducer is used to produce the sound waves.
Cardiogenic shock Treatment
The treatment of this condition aims at repairing cardiac muscles and organs that are damaged by lack of enough oxygen supply. This is a medical crisis and is usually treated by emergency life support. Patients are administered with additional oxygen to help them breathe properly. This reduces damage to their heart muscles and organs. If necessary, patients may be connected to a ventilator and given intravenous (IV) fluids and medications.
If medications and other non-operative procedures fail to improve the condition, surgery may be conducted on patients to cure cardiac problems and restore normalcy in blood supply.
Cardiogenic Shock Management
Management of this condition involves making a proper diagnosis. This can prevent further Ischaemia and cure the underlying problem. The condition can be managed by:
Ventricular assist devices
These are basically prosthetic ventricles which can support the performance of left and right ventricle and allow patients to survive until cardiac transplantation. These equipments are typically used when the cause of the Cardiogenic shock can be reversed and when IABP or medical treatment fail to bring about an improvement in condition. Ventricular assistance has been found to be safe and effective according to a recent study.
Non-invasive positive pressure ventilation (NIPPV)
Mild-to-moderate cases of the condition can be successfully cured with the aid of NIPPV, provided patients have enough blood pressure to withstand the therapy.
The management of Cardiogenic shock should always focus on unblocking the obstructed coronary vessels within the shortest possible time. This can be done through either of the two methods:
- Coronary Artery Bypass graft surgery (CABG)
Various medical studies have supported use of a stronger approach, along with early revascularization, to increase life expectancy of patients.
Cardiogenic Shock and Medications
Patients of this condition often require medicines to raise their blood pressure and improve the pumping ability of their heart. The medications typically used for this condition include:
These are generally administered to patients by emergency medical personnel as soon as they arrive on the scene, or right after they reach the hospital. Aspirin lowers coagulation (clotting) of blood and maintains its normal flow through a constricted artery. If patients doubt that they are going to have a heart attack, they can take aspirin while waiting for medical assistance. However, this should only be done if their doctors have instructed them to use it during a previous instance.
Also known as “Clot busters,” these medications make blood clots dissolve and remove obstruction of blood flow to the heart. The faster a thrombolytic drug is given after a heart attack, the higher the patient has a chance for survival. Typically, this type of medication is only used if there is unavailability of cardiac catheterization on an emergency basis.
In some cases, doctors provide patients with medications that act like Aspirin and help prevent formation of new clots. These involve drugs like platelet glycoprotein IIb/IIIa receptor blockers and Clopidogrel (Plavix). Such medications are administered in an emergency setting.
Some patients are provided medications like epinephrine or dopamine to support and improve the function of their heart until other curative methods begin to show an effect.
In some cases, blood-thinning medications like Heparin are likely to be administered to patients. This reduces the possibilities of blood clot formation in the bloodstream. Heparin is provided either through an injection or in an intravenous way. It is typically used in the initial days after an episode of heart attack.
Cardiogenic Shock and Angioplasty
Medical procedures, such as Angioplasty, aim at restoring flow of blood through the heart of patients. Emergency angioplasty helps unblock obstructed clogged coronary arteries and allows blood to flow more freely to the heart. Angioplasty is an operative procedure that involves insertion of a thin, long tube. The tube, known as catheter, is fitted with a special balloon and is passed through an artery (typically located in the leg) to access a clogged cardiac artery. Once the balloon is set into a perfect position, it is inflated for a brief duration to unblock an obstructed coronary artery. At the same time, blood flow to the heart may be restored by inserting a metal mash stent into the artery to keep it open for a prolonged duration. In the majority of patients, doctor keep the artery open by implanting a stent coated with a slow-releasing drug.
The symptoms of Cardiogenic shock tend to improve as soon as the flow of blood is restored through an obstructed artery.
Cardiogenic Shock and Balloon Pump
Picture 2 – Cardiogenic shock Picture
Balloon Pump is a highly effective method of treatment for this condition. Depending on the health of patients, doctors may prefer to implant a balloon pump in their aorta (primary artery of the heart). The balloon pump is designed to imitate the pumping action of a normal heart. It inflates and deflates just like a healthy heart, helping restore normal blood flow through the cardiac chambers.
Cardiogenic Shock and Surgery
If medical procedures and medications fail to bring about an improvement in the condition of a patient, doctors may advise surgery to cure Cardiogenic shock. This may involve operative procedures like:
Coronary Artery Bypass Surgery
It involves sewing arteries or veins in position at areas beyond a narrowed or blocked coronary artery. This repairs flow of blood to the heart. The process may be suggested by doctors after the heart has been allowed some time to recover following an attack.
Heart Valve Replacement
In some people, a cardiac injury in the form of a damaged valve or a ruptured chamber can lead to a Cardiogenic shock. If doctors detect an injury to be the cause, they may recommend a surgical correction of the problem.
Heart Pump Placement
It involves implanting ventricular assist devices (VADs) into the abdomen. These are fixed to a weakened heart to make it able to pump in a normal way. Implanted heart pumps can improve as well as prolong the lives of patients of end-stage heart failure who are waiting for a new heart or are not healthy enough to undergo heart transplantation.
In patients with a severely damaged heart, who do not respond to any other treatment, a heart transplant can be the only way to cure this condition.
Cardiogenic Shock Prevention
This condition can be prevented by avoiding a heart attack through changes in lifestyle, which include:
It is imperative to control high blood pressure (Hypertension) through regular exercise, medications, proper stress management, limiting alcohol and sodium intake and maintaining a healthy weight. This can help reduce chances of heart attack and consequently, the risk of a Cardiogenic shock.
High-risk individuals should quit smoking at the earliest. As per a medical study, the risk of heart attack for a former smoker is similar to a nonsmoker a few years after quitting.
Lowering dietary fat
Intake of less cholesterol and fat, particularly saturated fat, has been found to lower the risk of development of heart disorders. If dietary modification fails to control cholesterol, doctors may prescribe patients with special medications.
Cardiogenic shock Complications
Unless cured immediately, the condition may give rise to fatal complications. These involve damage to important organs, such as:
Organ damage usually occurs due to the inability of the heart to pump out enough oxygenated blood to various parts of the body. Damage to kidneys or liver can lead to further problems.
The kidneys release certain chemicals that aid in muscular functioning while the liver manufactures some proteins that help in coagulation of blood. The damage can be permanent depending on how long the patient remains in Cardiogenic shock.
Cardiogenic shock Risk Factors
Certain individuals are at a greater risk of having this condition than others. High-risk people include:
- Those who are 65 years of age or older
- Those having a history of heart failure or heart attack
- Those who have obstruction in several primary arteries of the heart, as in Coronary Artery Disease
In recent years, the death rate associated with this condition has reduced to 50-75% from around 80-90%. The condition can have a poor outcome unless treated immediately. Quick treatment of the underlying cause can reduce the danger of having this condition. If you experience symptoms of Cardiogenic shock, call the local emergency helpline or ask any of your family members to take you to the nearest hospital.