Cardiac ElectrophysiologyElectrophysiological ProcessesHeartModels, CardiovascularElectrophysiologic Techniques, CardiacEpicardial MappingArrhythmias, CardiacMyocytes, CardiacHeart Conduction SystemElectrophysiologyVoltage-Sensitive Dye ImagingElectrophysiological PhenomenaElectrocardiographyAction PotentialsHeart RateHeart VentriclesAtrioventricular NodeComputer SimulationMyocardiumCardiac OutputLeechesLong QT SyndromeCatheter AblationCardiac Surgical ProceduresMyocardial ContractionDeath, Sudden, CardiacPotassium ChannelsAlgorithmsCardiac Pacing, ArtificialTime FactorsHeart ArrestCardiotocographyGanglia, InvertebrateCardiomegalyHeart DiseasesCardiac CatheterizationCardiac TamponadeCardiac Complexes, PrematureCardiac-Gated Imaging TechniquesSignal Processing, Computer-AssistedPeriodicityBlood PressureHeart FailureCalciumHeart AtriaFMRFamidePatch-Clamp TechniquesMyoblasts, CardiacDogsBelizeCardiomyopathiesEchocardiographyReproducibility of ResultsBrain DeathBiological ClocksCardiac MyosinsCardiac Imaging TechniquesRats, Sprague-DawleyBlood CirculationCardiac GlycosidesHemodynamicsMembrane PotentialsSinoatrial NodeFourier AnalysisMyocardial InfarctionOctopodiformesCardiac Output, LowCardiotoxinsOut-of-Hospital Cardiac ArrestVentricular Function, LeftCardiac VolumeArrhythmia, SinusVentricular RemodelingHeart TransplantationVentricular FunctionTroponin IInterneuronsDisease Models, AnimalGestational SacCells, CulturedHeart Rate, FetalFractalsTreatment Outcome