The heart is a muscular pump that continuously pumps blood throughout the body. This pumping action is carried out due to the electrical impulses generated in the atrium of the heart. This electrical impulse causes the muscles to contract and relax, leading to a heartbeat. Thus, helping in pumping oxygenated blood throughout the body. When these electrical impulses short circuit, it causes a breakdown in the pumping mechanism. The heart stops pumping leading to sudden cardiac arrest.
What is Cardiac Arrest?
The sudden loss of function of heart due to the electrical system malfunction of the heart. It is also called as cardiopulmonary arrest or circulatory arrest. The blood supply to the heart is affected, causing a failure in contraction of the heart effectively. This affects the pumping mechanism causing blockage of blood flow to different organs in the body.
How is is Cardiac Arrest Different from a Heart Attack?
The heart attack is often confused with cardiac arrest. Many people think both the conditions are one and the same. However, these are two different scenarios that affect the condition of the heart. In case of a heart attack, that is also called as a myocardial infarction, the heart muscle tissues die due to loss of blood supply. This does not always lead to death of the patient.
In case of cardiac arrest, the heart suddenly stops working due to arrhythmias. This means one suffers from abnormal and irregular heart rhythms. The lower heart chambers misfire and do not pump blood properly. After a few minutes the heart stops beating and death may occur. Only immediate cardiopulmonary resuscitation or shock with a defibrillator will help restore heart rhythm and save a life.
Symptoms of Cardiac Arrest
Cardiac arrest occurs almost suddenly without any warning signs. Some of the symptoms of cardiac arrest include:
- Sudden loss of responsiveness
- Sudden collapses
- Loss of unconsciousness
- No signs of breathing
- Chest pain
What Causes Cardiac Arrest?
The abnormal heart rhythm is the main cause of cardiac arrest. This occurs when the electrical system of the heart goes haywire. The heart has specialized cells, present in the sinus node of the right atrium. These cells generate their own electrical impulses. These impulses helps in the normal pumping action of the heart.
The most common cause of arryhtmia (irregular heart beats) is ventricular fibrillation. The ventricles no longer pump blood, just fibrillates or quivers. Thus, the blood supply to the body is hampered and may cause death within a few minutes if not treated immediately.
Other causes of cardiac arrest include:
- Coronary heart disease where plaque builds up in the coronary artery. This causes reduction in blood supply to the heart muscles. This leads to partial or complete blockage of the blood supply to the heart. Thus, causing trouble with the electrical impulses, leading to cardiac arrest.
- Cardiomyopathy is a condition where the heart muscles enlarge or become thick causing arrhythmias, eventually leading to cardiac arrest.
- Other non-ischemic heart disease like hypertensive heart disease, congestive heart failure, etc. can lead to cardiac arrest.
- At times conditions other than cardiac disorders can lead to cardiac arrest. These include pulmonary embolism, aortic rupture, gastrointestinal bleeding, hemorrhage, etc.
- Other causes include hypovolemia, hypoxia, hyper or hypokalemia, hyper or hypoglycemia, etc.
Diagnosis of Cardiac Arrest
Absence of pulse is the first sign of cardiac arrest. Immediate treatment is recommended in such a case.
Treatment for Cardiac Arrest
Sudden cardiac arrest requires immediate resuscitation. The EMS staff needs to follow ‘chain of survival’ that includes:
- Early recognition
- Early CPR
- Early defibrillaton
- Early Advanced Cardiac Life Support
CPR or cardiopulmonary resuscitation is the most important step in saving a life due to cardiac arrest. Next comes defibrillation that helps in imparting electrical impulses to the heart. Medications such as epinephrine, atropine, etc. helps in short term spontaneous circulation of the heart.
Prognosis of Cardiac Arrest
Cardiac arrest has a very low survival rate, even in cases where patients receive immediate medical care. Patients who survive show mild neurological disability and a few develop severe to moderate impairment. However, after four years of having a cardiac arrest, 70% of the patients survived.
Cardiac arrest causes almost instant death in patients. It is important to take care of your heart health, especially when one has been diagnosed with a heart condition, diabetes or has a family history of heart conditions. Healthy diet and regular exercise will make sure your heart never suffers from electrical short circuits. Speak to your health care provider in detail if you have any queries regarding cardiac arrest.
Written by: Saptakee sengupta
Date last updated: February 25, 2015