Ventricular fibrillation is a serious cardiac disturbance that causes abnormal heart rhythms. It can be fatal. For many people with this condition, irregular heart rhythms are the first and only sign of coronary artery disease.
Ventricular fibrillation (VFib) may be confused with atrial fibrillation (AFib). Both involve irregular heart rhythms, but they affect different parts of the heart.
AFib can also signal a serious heart condition, but it is typically a symptom of a chronic problem, not a life-threatening feature in itself.
In emergency treatment, focus is on restoring blood flow as quickly as possible to the organs, including the brain. The patient may also receive treatment to minimize the risk of a recurrence.
Emergency treatments may include cardiopulmonary resuscitation (CPR) and use of a defibrillator.
Cardiopulmonary resuscitation (CPR)
Early CPR and early use of an AED can may a life.
Cardiopulmonary resuscitation (CPR) aims to restore blood flow through the body. Anybody with some basic life support training can do it.
In the past, CPR involved cycles of 30 chest compressions to the heart, and then two mouth-to-mouth resuscitation breaths.
Guidelines issued by the American Heart Association (AHA) in 2008 suggest that breathing into a person’s mouth may be unnecessary.
Instead, the responder should deliver about two compressions per second, or between 100 and 120 per minute. The chest should be allowed to rise back between compressions. Once they have started, they should continue until either emergency personnel arrive or somebody comes with a portable defibrillator.
Early CPR and the use of a defibrillator increases the person’s chance of survival.
Using a defibrillator
A defibrillator can be used together with CPR. The device sends electric shocks across the patient’s chest. The aim is to shock the heart back into normal activity. The shock may initially stop the heartbeat, but it can also stop chaotic rhythms and restore normal function.
A public-use defibrillator can be used by a layperson. These devices often have voice instructions on their use. A public-use defibrillator is programmed to detect ventricular fibrillation and emit a shock at the right moment.
In many countries, public-use, portable defibrillators are available in public places, such as airports, major train and bus stations, shopping malls, community centers, places where elderly people gather, casinos, and so on.
When the human heart beats, electrical impulses that trigger a contraction need to follow a specific route to the heart. If there is something wrong with the path of these impulses, arrhythmia, or irregular heartbeat, may occur.
Ventricular fibrillation happens when a problem in the lower chambers cause an irregular heart rhythm.
When the muscles in the four chambers of the heart tighten, a heartbeat occurs. During a heartbeat, a chamber closes and pushes blood out.
During a heartbeat, the muscular atria, or smaller upper chambers, contract and fill the relaxed ventricles with blood.
The contraction begins when the sinus node, a small group of cells in the right atrium, emits an electrical impulse which makes the right and left atria contract.
The electrical impulse continues to the center of the heart, to the atrioventricular node. This node is located on the pathway between the atria and the ventricles. From the atrioventricular node, the impulse travels through the ventricles, making them contract.
As a result, blood is pumped out of the heart and into the body.
A pain in the chest can be a sign of ventricular fibrillation.
The most common signs of ventricular fibrillation are sudden collapse or fainting, because the muscles and brain have stopped receiving blood from the heart.
About an hour before ventricular fibrillation, some people experience:
pain in the chest
tachycardia, or accelerated heartbeat, and palpitations
Versus atrial fibrillation
The left and right atria form the upper chambers of the heart, and the left and right ventricles form the two lower chambers. Together, all four chambers pump blood to and from the body.
When the atria, the two upper chambers, contract at an excessively high rate, and in an irregular way, the patient has atrial fibrillation (AFib). When the two lower chambers beat irregularly and flutter, the patient has ventricular fibrillation (VFib). Both produce an irregular heart rhythm.
Ventricular fibrillation is due to defective electrical impulses. It causes the ventricles to quiver uselessly, pumping virtually no blood into the body. The heart ends up without an effective heartbeat. Blood stops flowing around the body, and vital organs, including the brain, lose their blood supply.
A patient with ventricular fibrillation will typically lose consciousness very quickly and will require immediate, emergency medical assistance, including cardiopulmonary resuscitation (CPR).
If CPR is delivered until the heart can be shocked back into a normal rhythm with a defibrillator, the patient’s chances of survival are better.
VFib and AFib: Which is more serious?
Ventricular fibrillation is more serious than atrial fibrillation. Ventricular fibrillation frequently results in loss of consciousness and death, because ventricular arrhythmias are more likely to interrupt the pumping of blood, or undermine the heart’s ability to supply the body with oxygen-rich blood.
VFib can cause sudden cardiac death (SCD). SCD accounts for about 300,000 deaths annually in the United States. SCD can kill a victim in minutes, and it can occur even in people who seem healthy.
Chronic or persistent A-fib: What you need to know
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