Hi Norbi,

In the experimental setting occasionally you can record transient VF IN CPVT mice upon injection of epinephrine. In the clinical setting some VF do not respond to shocks in Brugada syndrome, and revert spontaneously.

Thanx Antonio, i had found about mice (link below). But what about human? May it theoretically/ practically happen with human?  

http://onlinelibrary.wiley.com/store/10.1111/j.1582-4934.2007.00016.x/asset/j.1582-4934.2007.00016.x.pdf?v=1&t=i534z89d&s=ba7eee2f2ae7b14edb28b7c99e56c50cb02bc01e

Hi Norbi

Fibrillatory arrest is a technique of myocardial preservation routinely being practised in cardiac surgery (most commonly for coronary artery bypass grafting) specially in patients with heavily calcified aorta or in those with atheromatous plaques interfering with aortic cross clamping. It avoids the risk of adverse neurological outcomes due to embolization of materials from the ascending aorta during aortic manipulation. The ventricle should simultaneously be protected from distension by the venting of left atrium/pulmonary veins.

It can either be Normothermic fibrillatory arrest  produced by placing an alternating current generator in contact with the ventricular myocardium. The energy consumption remains high as temperature is not reduced, and this can lead to subendocardial ischemia and infarction. This technique is thus not practiced.

The commonly used hypothermic fibrillatory arrest (HFA) is produced by cooling the body. Energy consumption of the myocardium is less than during warm ventricular fibrillation, but not as low as during complete arrest with the conventional high potassium cardioplegic cardiac arrest.

Hi Norbi

Transient VF is not uncommon finding. In the literature there are many case reports of transient VF. In the era of devices we see this commonly in the form of non-sustained ventricular tachycardia episodes. These are detected appropriately by the device and the treatment is usually aborted because they terminate early and spontaneously.

Other common examples are during Electrophysiologic Studies or Defibrillation threshold testing we sometimes induce VF, but it terminates spontaneously.

Finally, there are some diseases associated with recurrent non-sustained VF like CPVT, Brugada, and primary VF.

Raed A H Abu Sham'a, can i understand that NSVT on Holter or at cathlab is self terminating VF? Or how it understand?

The answer is NO. It is different mechanism.

There are several issues: 1. the rate - vf is usually thought to be faster than 300 bpm - the cycle less than 200 ms. 2. the extremely sick heart can't maintain the arrhythmia - cause the refractoriness is too long and the velocity in diseased muscle too low. The epidemiology indicate this - NYHA II-III vs IV mortality cause. The appropriate distinguishing is in my opinion not possible to differentiate fast vt from 'slow' vf. I agree with Dr Raed that the difference is in mechanisms of spatial organization of the wave.