Myocardial infarction (heart attack) is associated with Chlamydia pneumoniae, cytomegalovirus and Coxsackie B virus (an enterovirus). (Coxsackie B virus is also associated with sudden unexpected death due to myocarditis).
GuillainBarré syndrome is associated with the bacterium Campylobacter jejuni, and with the viruses cytomegalovirus and enterovirus.