Ventricular fibrillation

Ventricular fibrillation, and ventricular fibrillation (VF ) called, is a life-threatening pulseless heart rhythm disorder in the run unordered excitations in the heart chambers and heart muscle contracts no longer sorted. If left untreated, ventricular fibrillation because of the lack of heart pumping directly to death. The ECG can be seen Flimmerwellen with a frequency of about 300-800/min. Ventricular fibrillation, for example, as a complication of a heart attack may occur (see also sudden cardiac death ).

Pathophysiology

In general, the whole of the heart muscle works by control via the excitation line coordinate system together. In the sinus node, the excitations are regularly created and passed to the atria, the atrioventricular node it passes to the ventricles, where they over specialized cells - are forwarded to all parts of the ventricles - the conduction system. Thus, all parts of the heart muscle are excited in a meaningful sequence, they contract itself, the excitement is back again and the heart muscle cells are ready for a new emotion.

When ventricular fibrillation occurs by local disturbances of conduction or of the excitation process to the fact that the propagating excitation encounters tissue that is excitable again and the excitement forwarding continues. There will be circular excitation waves, so that the heart muscle no longer coordinated pumping, but uncoordinated with high frequency jerks - it " flickers ". The pumping capacity of the heart decreases abruptly to zero and there is a cardiac arrest.

Therapy

The treatment of ventricular fibrillation is immediate defibrillation. It ( 150-360 J mono- or biphasic) all cardiac muscle cells energized simultaneously to after starting the excitation takes place in the normal way from the sinus node through a brief, strong surge. Defibrillation is the only promising treatment of ventricular fibrillation. The sooner it is done, the higher the chances of success. Every minute without defibrillation reduces the likelihood of successful resuscitation by about 10 %.

The time to the availability of a defibrillator must be bridged by first aid measures ( cardiopulmonary resuscitation ) to maintain the oxygen supply, especially of the brain, the kidneys and the heart muscle.

The increasing diffusion of semi-automatic defibrillators, which are kept in public places and are designed for use by lay people, the time period can often be significantly reduced to defibrillation.

Through these devices, the chance of survival increases by a multiple. In an early cardiopulmonary resuscitation and defibrillation by emergency medical services the patient has statistically a chance of survival of approximately 8 to 10%. This is increased by the early use of an automated external defibrillator by lay rescuers up to 50 %.