Circadian RhythmHeartHeart RateHeart FailureHeart DiseasesHeart Defects, CongenitalHeart TransplantationHeart AtriaFetal HeartPeriodicityBiological ClocksSuprachiasmatic NucleusHeart ValvesHeart BlockPeriod Circadian ProteinsCircadian Rhythm Signaling Peptides and ProteinsActivity CyclesAtrial FibrillationSleep Disorders, Circadian RhythmPhotoperiodCircadian ClocksMyocardiumTime FactorsCLOCK ProteinsAlpha RhythmMyocardial ContractionHeart Arrest, InducedHeart Function TestsARNTL Transcription FactorsMyocardial IschemiaAnti-Arrhythmia AgentsElectric CountershockMyocytes, CardiacCardiac Pacing, ArtificialHemodynamicsHeart ArrestChronobiology DisordersCoronary DiseaseDarknessLightVentricular Function, LeftCardiac Output, LowEchocardiographyCardiomyopathy, DilatedRheumatic Heart DiseaseStroke VolumeMotor ActivityBody TemperaturePerfusionTreatment OutcomeHeart Rate, FetalRisk FactorsCardiomegalyHeart SeptumCardiotonic AgentsCardiomyopathiesDogsRats, Sprague-DawleyHeart, ArtificialAdrenergic beta-AntagonistsProspective StudiesHeart Failure, SystolicVentricular Dysfunction, LeftElectrocardiographyFollow-Up StudiesMyocardial InfarctionElectrocardiography, AmbulatoryAutonomic Nervous SystemHeart InjuriesRats, WistarSleepCryptochromesMyocardial Reperfusion InjuryAction PotentialsCatheter AblationHeart Valve ProsthesisBeta RhythmChronic DiseaseAtrioventricular NodeSinoatrial NodePacemaker, ArtificialVentricular RemodelingRespirationHeart Failure, DiastolicDisease Models, AnimalModels, CardiovascularAmerican Heart AssociationSympathetic Nervous SystemAmiodaroneArrhythmia, SinusOxygen ConsumptionJet Lag SyndromeTelemetryDelta RhythmRNA, MessengerElectrophysiologic Techniques, CardiacHeart Conduction SystemArrhythmias, CardiacEndocardiumExercise Test