Angina Pectoris, VariantAngina PectorisErgonovineCoronary VasospasmAngina, UnstableIsosorbide DinitrateAngina, StableElectrocardiographyCoronary AngiographyCoronary VesselsMicrovascular AnginaSpasmNicorandilNitroglycerinThiobarbituratesElectrocardiography, AmbulatoryHyperventilationExercise TestLudwig's AnginaCopper SulfateVasodilator AgentsCoronary DiseaseCalcium Channel BlockersMyocardial IschemiaCoronary CirculationMyocardial InfarctionAcetylcholineFollow-Up StudiesAutonomic Nervous System