>>6470
There is nothing that could change in blood chemistry what could stop heart but I guess it may fail because of a panic attack and lack of oxygen in the blood as this is not an uncommon thing for people who have heart problems heart. Just like the brain, the heart also needs oxygen and probably even more than the brain and if it happens to be half dead already, it does not take much to stop it.

There is a video of robber dropping dead during the robbery because of cardiac arrest