Ventricular fibrillation
From ArticleWorld
Ventricular fibrillation is a severe cardiac condition, characterized by a lack of coordination of the muscle tissue that controls the ventricles. The VF leads to a complete heart stop in a matter of seconds, which makes it a medical emergency. It is a common cause of cardiac arrest and sudden cardiac death.
Description and causes
The causes that underlay occurrence of VF are not known completely. Statistics show that most persons affected by VF have different heart diseases, but VF is reported to have occurred on completely healthy hearts as well.
VF is a common manifestation of an ischaemic heart disease, but is also associated to cardiomyopathy, myocarditis and usage of cardiotoxic drugs.
The electrocardiogram shows a fairly random waveform, although it does have a dominant frequency, and a peak in power spectrum of 9-12 Hz, depending on drugs and disease evolution. However, recent theories began to question even this, as the validity of the ECG is doubtful when taking Doppler effect into account.
At the moment, there is no exact, formal leading theory about the causes of VF. Some recently described syndromes like the Brugada Syndrome gave researchers some clues, but medical science is still unable to give a relevant explanation about the occurrence of VF on normal hearts. Even more, much of the data seems to be completely unexplainable in terms of numbers, with arrhythmia occurring and changing parameters without any obvious reason, and, due to the practical problems involved (monitoring large areas of the heart at the same time in the context of resuscitation), much of the data is not even real, but obtained by computer simulation.
Treatment
The treatment of ventricular fibrillation is quite similar to that in case of atrial fibrillation. VF is generally reversible by electric discharge of direct current from a defibrillator. Arrhythmic agents may sometimes be of limited use, but VF, unlike atrial fibrillation, seldom resolves spontaneously. Defibrilation remains the only more successful treatment.
Codes:
- ICD-10 code: I49.0
- ICD-9 code: 427.41