Cardiac Arrest – also called Sudden Cardiac Arrest (SCA) or Cardiopulmonary Arrest – is the sudden, unexpected stoppage of normal blood circulation due to ineffective heart action.
Either the periodic impulses that trigger the coordinated heart muscle to contract cease or ventricular fibrillation and/or flutter occurs in which the individual muscle fibers have a rapid, irregular twitching.
Arrested blood circulation prevents delivery of oxygen to all parts of the body. Lack of oxygen supply to the brain causes victims to lose consciousness and to stop normal breathing, although gasping or labored breathing may still occur.
Brain injury is likely if SCA is untreated for more than five minutes, although new treatments such as induced Therapeutic Hypothermia can extend this time. To improve survival and neurological recovery, immediate response is critical.
The majority of cardiac arrest victims suffer from ventricular fibrillation (v-fib) and most have severe coronary artery disease.
The only chance of survival for many is immediate and successful implementation of emergency cardiac care and cardiopulmonary resuscitation (CPR).
Although cardiac arrest is usually related to preexisting coronary artery disease, there are other events that bring about cardiac arrest.
These include the cessation of heart and lung action as a result of drowning, suffocation, electrocution, severe accidental trauma or drug overdose.
Programs aimed at reducing death from cardiac arrest include education in ways to avoid the development of coronary artery disease in the first place.
Secondarily, is the training of health care professionals and volunteers in the techniques of CPR and emergency cardiac care.
Sudden Cardiac Arrest Is Not A Heart Attack
A heart attack happens when the blood supply to the heart muscle is suddenly blocked, resulting in the death of the heart muscle.
Heart attack victims usually experience chest pain and remain conscious. Heart attacks are serious and sometimes will lead to sudden cardiac arrest.
However, sudden cardiac arrest may occur independently of a heart attack and without warning signs. Sudden cardiac arrest results in death if not treated immediately.
Symptoms of Sudden Cardiac Arrest
- A racing heartbeat
- Feeling dizzy or light-headed just before you faint
- Chest pain
- Shortness of breath
- Nausea (feeling sick to the stomach) or vomiting
- Loss of consciousness
- Loss of pulse and blood pressure
- Abnormal breathing
Symptoms of a Heart Attack
- Chest pains - uncomfortable pressure, tightness of the chest
- Pain in the arms, neck, jaw and shoulder
- Labored breathing
- Heart palpitations
Causes of Cardiac Arrest
The immediate cause of cardiac arrest is an abnormality in your heart rhythm or arrhythmia. Ventricular fibrillation (v-fib) causes most SCA. During v-fib, the ventricles (the heart's lower chambers) don't beat normally.
Instead, they quiver very rapidly and irregularly. When this happens, the heart pumps little or no blood to the body. V-fib is fatal if not treated within a few minutes.
Other problems with the heart's electrical system can also cause SCA. Unlike other muscles that rely on nerve connections to receive the electrical stimulation needed to function, the heart has its own electrical stimulator.
It's a specialized group of cells called the sinus node, located in the upper right chamber (right atrium) of your heart.
If something goes wrong with the sinus node or the flow of electric impulses through your heart, an arrhythmia can result, causing your heart to beat too fast, too slow or in an irregular fashion.
Certain diseases and conditions can cause the electrical problems that lead to SCA. These include:
- Coronary heart disease (CHD), also called coronary artery disease
- Severe physical stress
- Certain inherited disorders
- Structural changes in the heart
Diagnosis of Cardiac Arrest
Proper diagnosis begins with a doctor consultation that includes a review of the patient's medical history and family medical history, including risk factors for sudden cardiac arrest.
Several screening and diagnostic tests may be used to determine if a patient is at risk:
- Genetic Testing – helps detect a patient's risk for SCA
- Imaging Tests – such as chest X-ray, echocardiogram, computed tomography (CT) scan, magnetic resonance imaging (MRI) or a nuclear scan that identifies blood flow problems in the heart
- Clinical Laboratory Tests – such as an electrocardiogram (EKG) or coronary catheterization (angiogram)
The kind of treatment(s) you may receive depends on the severity of your condition. Possible treatments include:
Cardiopulmonary resuscitation (CPR) is the reestablishing of heart and lung action after cardiac arrest or apparent sudden death. This can be the result of electric shock, drowning, respiratory arrest and other causes. The two major components of CPR are artificial ventilation and closed-chest cardiac massage.
- Cardiac Catheterization
The insertion of a catheter into a vein or artery, then guiding it into the interior of the heart to measure cardiac output, oxygen content of blood in the heart chambers and evaluate structural components of the heart.
The procedure is required whenever a precise diagnosis is needed to determine if heart surgery is necessary and to plan the surgical approach.
- Intra-Aortic Balloon Pump
- Respiratory support (ventilator)
- Therapeutic Hypothermia Treatment
A medical treatment that lowers a patient's body temperature in order to help reduce the risk of the ischemic injury [restriction or thinning] to
tissue following a period of insufficient blood flow.
Therapeutic hypothermia may be induced by invasive means using a catheter placed in the femoral vein, or by non-invasive means. This usually involves a chilled water blanket or torso vest and leg wraps in direct contact with the patient's skin.
Studies have shown that patients at risk for ischemic brain injuries have better outcomes if treated with a hypothermia protocol