Ventricular fibrillation
E-mail this E-mail this     Print Print this    
Ventricular fibrillation or VF is the rapid, irregular quivering of the heart, originating from the lower ventricles. It often follows other heart conditions such as heart attack or ventricular tachycardia, also known as VT. VT and VF are often confused for one another, but where as ventricular tachycardia involves a sudden fast and regular rhythm of contraction, ventricular fibrillation causes the entire heart to move out of sync rapidly and prevents it from pumping blood at all. At this point the heart is described as “a bag or worms” – referring to the rapid and erratic movement of each heart muscle fiber. The rhythm can exceed 350 beats per minute. This makes it life threatening as the heart may eventually stop beating and pumping blood as a result. Studies have already shown that the human body cannot survive an episode of VF longer than four minutes without suffering long term organ damage as they lack the necessary oxygen to function. It is a common cause of cardiac death, and accounts for 75% to 85% of sudden deaths due to heart conditions.


Upon the beginning of an attack of VF, usually the patient just collapses or loses consciousness as the brain’s blood supply is cut off immediately after the heart stops pumping blood. Pulse becomes very weak or absent, while the heart beat can become very erratic. However, there are some discernable symptoms which can occur up to an hour before the attack strikes. These symptoms include chest pain, headaches and dizziness, nausea, rapid heart beat and slowness of breath. Ventricular tachycardia can also occur before completely succumbing to VF.


Similar to VT, ventricular fibrillation is caused by anomalies in the electrical signals that signal the beating of the heart. In the case of VF, the signals cause very erratic behavior in the heart muscles and the affected portion twitches erratically so much that the pumping of the blood is disrupted. Scarring on the surface of heart muscles can increase the risk of electrical signals misfiring.


As such, many existing heart conditions can become risk factors for triggering VF. The presence of a ventricular fibrillation episode can deteriorate into a VF attack, and as such VT is a risk factor for the occurrence of VF. These include congenital heart conditions, electrical shock or trauma occurring over the surface of the heart, ischemia or more commonly, previous heart attacks. Heart surgery or a near drowning episode may also trigger ventricular fibrillation. However, VF can occur even without a history of heart disease as any moment where the heart lacks oxygen can trigger an episode. Other risk factors include smoking, diabetes, and high blood pressure as these can increase the risk for other cardiovascular conditions.
Ventricular Fibrillation
Image: ...

Other conditions such as a low potassium or sodium levels in the blood can cause VF, as well as hypothermia or a very low body temperature. Certain anti-arrhythmic drugs may also accidentally trigger VF, so doctors must also check if the patient is taking other forms of medication which may trigger VF.


Upon onset of ventricular fibrillation in an emergency situation outside a hospital, CPR or cardiopulmonary resuscitation is necessary once cardiac arrest occurs. It should be continuously administered until defibrillators can be used. It aims to try to keep the patient breathing and his or her heart beating, or making beat again once it has stopped. First the patient’s breathing is checked and the airways are checked to make sure that they are not blocked. If the patient is not breathing, chest compression and resuscitative breathing may be done.


Defibrillators are also used in order to shock the heart into resuming a working heartbeat rhythm. It is commonly used for emergency cases of cardiac arrest, in order to save the life of the VF sufferer. More commonly now, automated external defibrillators or AEDs are now available in public places for use in such an emergency situation. During an episode of VF, if the heart rhythm is unable to return to a normal working beat then increasing power may be applied with the defibrillator.

If the heart beat has yet to return to normal even after defibrillation, drugs might be administered in order to stimulate the heart into beating again.

Another treatment which the doctor can use to treat and prevent future attacks is to place and implanted device known as an implantable cardioverter defibrillator or ICD. This is a device similar to a pacemaker that it is attached to the heart by wires. It detects abnormal heartbeat rhythms and administers an electric shock on the onset of an episode in an attempt to restart the heart’s rhythm. Defibrillation is one of the most effective treatments to stop VF attacks, and it is important to administer it as soon as possible. If VF is not stopped within 5 minutes the patient may suffer permanent brain damage.

Specific treatment for VF will depend on the patient’s medical history and as such, after the VF attack the doctor may administer ECG and blood tests to verify the cause of VF. It is very important that other potential causes of irregular heartbeat in the form of other cardiovascular conditions be treated, as VF is harder to treat due to its unpredictable nature.

A low sodium and low cholesterol diet may benefit people suffering from ventricular fibrillation as these help ease circulation problems by maintaining blood pressure and keeping blood vessels clear of blockage. Proper diet may also help balance any deficiencies or excesses in blood chemistry which can trigger VF.


However, ventricular fibrillation may not be easily preventable due to its unpredictability and the treatments, particularly the ICD, mentioned above can help quickly resolve VF attacks. Correct treatment of other existing heart conditions can prevent VF from reoccurring as well. Careful monitoring of physical activity may be necessary to prevent sudden episodes. The doctor may be able to help determine the intensity of physical activity you may perform to prevent another VF attack.
  Member Comments

Medication commonly used for these disease:

drugs Ventricular fibrillation drugs