Does glutamate affect the cardiological system? Could it play a role in tachycardia and palpitations?

A bit too gee-whiz. Glutamate receptors exist in peripheral tissues, i.e., outside the CNS. Animal research in this field goes back 15-20 years. Cardiac effects in animal studies are indirect, i.e. neurally mediated. not myocardium-mediated. Effects in humans at this point are mostly conjectural. There's a lot of totally unscientific sensationalist drivel on the Web about how bad MSG is. So no jumping to conclusions.