Pacemaker, ArtificialEnergy MetabolismEnergy IntakeEnergy TransferBiological ClocksSinoatrial NodeMilkHeart BlockEquipment FailureAtrioventricular BlockBradycardiaFluorescence Resonance Energy TransferElectric Power SuppliesConservation of Energy ResourcesSolar EnergyHyperpolarization-Activated Cyclic Nucleotide-Gated ChannelsThermodynamicsCircadian RhythmRenewable EnergyElectrodes, ImplantedTime FactorsInterstitial Cells of CajalPower PlantsSuprachiasmatic NucleusBasal MetabolismEquipment DesignComputer SimulationEnergy DrinksDevice RemovalElectrocardiographyArrhythmias, CardiacEquipment SafetyBlastomycosisPeriodicityCalorimetry, IndirectBody WeightAction PotentialsModels, BiologicalEatingCyclic Nucleotide-Gated Cation ChannelsHeart RateElectrophysiologyPower (Psychology)Atrioventricular NodeModels, MolecularKineticsOxygen ConsumptionBody CompositionMembrane PotentialsDefibrillators, ImplantableAlgorithmsIon ChannelsDietary ProteinsAdenosine TriphosphateModels, ChemicalArrhythmia, SinusFlufenamic AcidTemperaturePeriod Circadian ProteinsAtrial FibrillationHeart AtriaDietary FatsSyncopeNeuronsEnergy-Generating ResourcesCalorimetryTachycardiaAtrial FunctionLinear Energy TransferDietary CarbohydratesElectromagnetic FieldsTelemetryBioelectric Energy SourcesLightEquipment Failure AnalysisTreatment OutcomeProsthesis ImplantationHeartFeeding BehaviorForeign-Body MigrationProtein ConformationModels, TheoreticalGlucoseWaterCalciumNuclear Power PlantsElectromagnetic PhenomenaMotor ActivityPotassium ChannelsNitrogenBiomechanical PhenomenaProteinsReproducibility of ResultsBody Temperature RegulationDogsWeight GainQuantum TheoryFollow-Up StudiesMuscle, SkeletalAnimal Feed