Heart AtriaHeart VentriclesVentricular Function, LeftPulmonary VeinsAtrial FunctionHeartAtrial Function, LeftVentricular Dysfunction, LeftMyocardial ContractionEchocardiographyAtrial FibrillationMyocardiumVentricular FunctionDogsHypertrophy, Left VentricularCerebral VentriclesHeart NeoplasmsCatheter AblationElectrocardiographyHeart Conduction SystemEndocardiumElectrophysiologic Techniques, CardiacMitral ValvePericardiumThird VentricleStroke VolumeHeart SeptumFourth VentricleEchocardiography, TransesophagealHeart AneurysmCardiac Pacing, ArtificialHemodynamicsDiastoleBody Surface Potential MappingVentricular RemodelingSystoleVena Cava, SuperiorLateral VentriclesMitral Valve StenosisCardiac VolumeHeart FailureMyxomaFistulaHeart RateCardiac CatheterizationBlood PressureVentricular PressureCardiac Surgical ProceduresCerebral Ventricle NeoplasmsCoronary CirculationModels, CardiovascularAngiocardiographyCardiomegalyCardiomyopathy, DilatedHeart Defects, CongenitalAtrial Function, RightTreatment OutcomeTime FactorsMyocardial InfarctionHeart DiseasesEchocardiography, Doppler, ColorMitral Valve InsufficiencyVentricular Function, RightAtrial AppendageCardiomyopathiesCoronary SinusEchocardiography, DopplerHeart Septal Defects, AtrialHeart InjuriesFetal HeartCoronary VesselsAtrial SeptumPulmonary ArteryPapillary MusclesPacemaker, ArtificialCardiotonic AgentsRefractory Period, ElectrophysiologicalMyocytes, CardiacGuinea PigsMyocardial IschemiaAnti-Arrhythmia AgentsEchocardiography, Three-DimensionalTomography, X-Ray ComputedCardiac OutputHeart Septal Defects, VentricularAtrial Natriuretic FactorOrgan SizeCor TriatriatumCardiomyopathy, HypertrophicTachycardiaDisease Models, AnimalRats, WistarAction PotentialsSinoatrial NodeArrhythmias, CardiacTransposition of Great VesselsVentricular Dysfunction, RightFollow-Up StudiesTricuspid ValveIsoproterenol