What if it's not his heart?  Let's work from the tenuous assumption that we're not idiots who've spent days examining a heart up, down, sideways "ï¿½ declaring it healthy just a few hours before it basically shut down. So we need to think about causes in places you didn't look.
Sinoatrial block.
Extreme bradycardia could be caused by sick sinus syndrome.
Extreme bradycardia could be caused by sick sinus syndrome. [SEP] Sinoatrial block. [SEP] What if it's not his heart?  Let's work from the tenuous assumption that we're not idiots who've spent days examining a heart up, down, sideways "ï¿½ declaring it healthy just a few hours before it basically shut down. So we need to think about causes in places you didn't look.