Ventricular fibrillation is a serious, life-threatening condition belonging to the group of cardiac arrhythmias. It is a condition incompatible with life, and therefore requires immediate medical attention. The essence of ventricular fibrillation is disordered contractions of the ventricular muscles, which begin to fibrillate instead of contracting regularly, preventing the heart from pumping any blood into the body. This leads to cardiac arrest.
Structure and Function of the Heart
The heart consists of 4 sections; the right atrium, right ventricle, left atrium and left ventricle. Blood from the body flows into the heart, into the right atrium. It proceeds into the right ventricle, which pumps the blood into the lungs so that it can be oxygenated and returned back to the heart, into the left atrium. From the left atrium the blood flows into the right ventricle, which pumps it to the rest of the body. The entire cardiac cycle depends on the contractions of the cardiac muscle. The cells of the heart are specialized in order to form and send electrical impulses among each other, which activate and cause the coordinated contractions of the heart cells by first contracting the muscle of the atria, sending the blood into the ventricles, and then contracting the ventricles, which pump blood to other sections. In a healthy heart, the electrical impulses form in special cells in the right atrium inside the sinus node. From here they spread under strict control between cells of the atrium and convert over to the next cluster of specialized cells, called the atrioventricular (AV) node, into the cells of the ventricles.
The Emergence of Ventricular Fibrillation
Ventricular fibrillation occurs when the heart is severely damaged and the cells ignore commands from the control center. This results in the cells forming their own random, chaotic impulses. The cells do not contract at the same time and this leads to the absence of any real contractions. Therefore the heart does not pump any blood to the body, causing cardiac arrest. Ventricular fibrillation emerges after damage to the cells of the heart following acute myocardial infarction, an electric shock, heart failure or the final stages of heart disease. The risk of ventricular fibrillation is higher when suffering from a congenital disorder of the cardiac conduction system. Ventricular fibrillation can be caused by certain medication used to treat heart rhythm disorders or a mineral imbalance in the blood, namely low potassium levels, low magnesium levels, or high levels of calcium. Ventricular fibrillation often occurs in individuals with a certain predisposition and in this case, the first sign of heart problems can be death.
Symptoms of Ventricular Fibrillation
Ventricular fibrillation is a severe condition which is not compatible with life on a long-term basis. Symptoms of ventricular fibrillation include collapse and loss of consciousness, which may be preceded by chest pain, increased heart rate, palpitations, nausea or dizziness. These are symptoms that emerge in many different diseases, therefore it is not possible to know immediately whether ventricular fibrillation is the cause simply based on the symptoms.
First Aid during Ventricular Fibrillation
Patients with ventricular fibrillation need to be resuscitated i.e. indirect massaging of the heart by the exact given algorithm. It is also necessary to use a defibrillator as soon as possible. Defibrillation means to place two electrodes onto the chest which send electrical shocks to interrupt chaotic activity of the heart and allow the accession of a regular rhythm. Nowadays an alternative is the AED, an automated external defibrillator, which is available in places frequented by a large number of people, such as airports, railway stations, shopping centers and cinemas. This device communicates with the rescuer and gives precise instructions on how to proceed in order for the rescue to be successful. It is also very important to call for medical assistance. If the patient survives, a cardioverter-defibrillator is recommended. A cardioverter-defibrillator is a device that is implanted under the skin and is able to detect ventricular fibrillations and subsequently stop it using electric shocks, returning the heart to a normal rhythm before collapse of the affected individual. In the event that no device is available and ventricular fibrillation is suspected, a precordial thump can be performed. This is a blow to the lower section of the sternum using the ball of one's hand, which can interrupt fibrillation and restore the natural rhythm of the heart.
Risk Factors of Ventricular Fibrillation
Risk factors of ventricular fibrillation include heart rhythm disorders and heart conditions in general. Damaged heart cells are easily led into chaotic and uncoordinated activities. At a higher risk of the emergence of ventricular fibrillation are individuals suffering from extrasystoles; extra contractions of the ventricles occurring independently of the sinus node. Such contractions can directly induce ventricular fibrillation. Ventricular fibrillation frequently appears in individuals with disturbed neural regulation of the heart's activity as well. Consequences of ventricular fibrillation is often death if the affected individual does not receive immediate help. The nerve cells die of lack of oxygen in 4 to 5 minutes, which means that even during prompt intervention, ventricular fibrillation can cause irreversible brain damage.
Prevention of Ventricular Fibrillation
Prevention of ventricular fibrillation is related to the prevention of all cardiovascular diseases. If the patient suffers from arrhythmia, which can lead to ventricular fibrillation, it is necessary to introduce a cardioverter-defibrillator in to the patient's heart, which can immediately prevent ventricular fibrillation. It pays not to underestimate the symptoms of heart diseases such as chest pain, breathing difficulties, sudden heart palpitations, nausea, weakness and fatigue. It is important to remember that ventricular fibrillation can occur suddenly, without warning or prior symptoms, therefore it is important to attend preventative medical examinations regularly with a general practitioner, who can detect irregular cardiac activity even if the affected individual does not experience any symptoms.