Coronary SinusCoronary CirculationCoronary VesselsCoronary AngiographyCoronary Artery DiseaseSinus of ValsalvaAngioplasty, Balloon, CoronaryCoronary StenosisCoronary Artery BypassCranial SinusesMaxillary SinusCoronary DiseaseParanasal SinusesCardiac Pacing, ArtificialCavernous SinusCoronary Vessel AnomaliesElectrocardiographyBlood Flow VelocityCoronary AneurysmVena Cava, SuperiorCarotid SinusCoronary VasospasmHeart AtriaCatheter AblationRegional Blood FlowFrontal SinusCardiac CatheterizationParanasal Sinus DiseasesSphenoid SinusDogsPacemaker, ArtificialHeart Conduction SystemTreatment OutcomeMyocardial InfarctionMyocardiumAtrial FibrillationAtrioventricular NodeCoronary ThrombosisElectrophysiologic Techniques, CardiacSinus Thrombosis, IntracranialHeart Arrest, InducedHeartTime FactorsSick Sinus Syndrome