Heart and the muscles of the heart play a pivotal role in sustaining the human life. The muscles of the heart are controlled by an electrical system which determines the normal heart rate and rhythm of a person. An electrical signal which moves across the heart from top to the bottom corresponds to a heartbeat. Each electrical signal contracts the heart muscles and pumps blood. However, there are certain conditions which disrupt the normal rate and rhythm of the heart such as Arrhythmia. Arrhythmia is the condition in which the normal rate of heart beat can either become too slow or too fast or beat with an irregular rhythm. This condition raises the risk of stroke, heart attack or cardiac arrest. This is when procedures like cardioversion and defibrillation come handy.
Cardioversion and Defibrillation:
It is commonly believed that both cardioversion and defibrillation are similar procedures as they both involve sending electrical shocks to the heart. However, both these procedures do have some differences.
- Cardioversion can be defined as a procedure to restore a normal heart rhythm and rate in a person who experiences arrhythmia. Defibrillation is a process in which an electronic device is used to send electrical shocks to a patient who is experiencing a dangerous form of arrhythmia or a cardiac arrest.
- Cardiovesrion can be administered in two ways- an electrical form or as medicines. Defibrillation is only administered using only devices called as defibrillators.
- In pharmacologic or chemical cardioversion the doctors prescribe medicines to establish the normal rhythm or beats of the heart. However, when these medicines fail doctors prescribe electrical cardioversion. This involves sending in electrical shocks to the heart to restore regular rhythm and speed of heart beat.
- Electrical cardioversion is performed under sedation in a medical practitioner’s office where a single shock lasting less than a second is given to the heart to set right the abnormal rhythms through paddles (which are electrodes) placed in the front and back of the patient. Sometimes more than one shock can also be given and patient can continue normal activities after the procedure.
- Defibrillation is a procedure in which an electronic device defibrillator is used to send electrical shocks to the heart during emergency situations such as cardiac arrhythmia, ventricular fibrillation and pulseless ventricular tachycardia.
- Defibrillators are of different types such as external, transvenous and implanted defibrillators. Portable defibrillators known as automated external defibrillators or AEDs are now available.
- Cardioversion is a synchronized procedure that sends electrical energy that coordinates with the R wave of the heart. Defibrillation on the other hand is an immediate procedure that sends in electrical energy to the heart at any point of the cardiac cycle. Cardioversion is not an emergent procedure unlike defibrillation.
- Electrical cardioversion is often undergone electively to treat non emergency cases of arrhythmia. This technique is also used to treat atrial flutter, atrial and ventricular tachycardia. The patient has a pulse but is sometimes unstable. The procedure aims at establishing the normal sinus rhythm in a person. Sometimes this treatment is also used in emergency situations and when a person’s heart rate is over 150beats per minute. Defibrillation is used in conditions such as pulseless ventricular tachycardia and ventricular fibrillation.
Both the procedures though done to regulate irregular heart beat and rhythm though often carry with it a certain amount of risk such a brain stroke. It is advisable that these procedures are carried out under strict medical supervision and by trained medical professionals.