Experimental study of arrhythmia due to mild therapeutic hypothermia after resuscitation of cardiac arrest

The therapeutic hypothermia (under 34 °C-32 °C during 12 - 24h) can help reduce cerebral oxygen demand and improve neurological outcomes after the cardiac arrest. However it can have many adverse effects. The cardiac arrhythmia generation represents an important part among these adverse effects. In order to study the arrhythmia generation after therapeutic hypothermia, an experimental cardiomyocytes model is used. The experiments showed that at 35 °C, the acquired extracellular potential of the culture are characterized by period-doubling phenomenon. Spiral waves are observed as well in this case. The results suggested that the global dynamics of therapeutic hypothermia after cardiac arrest can be represented by a Pitchfork bifurcation, which could explain the different ratio of arrhythmia among the adverse effects after this therapy. A variable speed of cooling / rewarming, especially when passing 35 °C, would help reduce the post-hypothermia arrhythmia.