I’m currently sitting in a CPR class and I was able to stump the instructor with this question.

I know that during cardiac arrest, the hearts electrical signals are disturbed or stopped. Then this happens, we perform CPR in order to continue the flow of oxygenated blood to the brain.

So here is my question:

The heart has four major 1-way check valves that the blood flows through: the mitral valve, the tricuspid valve, the aortic valve and pulmonary valve. With no electrical signals telling these valves what to do, during CPR compressions, with these valves continue to only allow blood to flow one way? Or will the valves not operate normally without the electrical signals and allow the blood to blow backwards?

Thanks for any help!