Heart VentriclesHeartMyocardiumHeart AtriaHeart RateCerebral VentriclesThird VentricleFourth VentricleHeart FailureAtrial FunctionHeart Defects, CongenitalLateral VentriclesHeart DiseasesMyocardial ContractionCerebral Ventricle NeoplasmsFetal HeartHeart TransplantationDogsVentricular FunctionHeart ValvesEchocardiographyHeart NeoplasmsAtrial FibrillationHeart BlockCardiac Pacing, ArtificialVentricular Function, LeftHeart SeptumHeart Conduction SystemEndocardiumHemodynamicsMyocytes, CardiacAtrial Function, RightCardiomegalyPulmonary VeinsHeart Function TestsElectrophysiologic Techniques, CardiacVentricular Function, RightStroke VolumeModels, CardiovascularHeart InjuriesMyocardial IschemiaSinoatrial NodeHeart Arrest, InducedCardiomyopathy, DilatedElectrocardiographyVentricular Dysfunction, LeftCatheter AblationPerfusion