Atrial Function, LeftAtrial FunctionAtrial Function, RightHeart AtriaEchocardiography, DopplerAtrial FibrillationVentricular Function, LeftEchocardiography, Doppler, PulsedPericardiectomyElectric CountershockStroke VolumeEchocardiographyMyocardial ContractionHeart Function TestsEchocardiography, TransesophagealVentricular FunctionObserver VariationBlood Flow VelocityHemodynamicsVentricular Dysfunction, LeftHypertrophy, Left VentricularHeart FailureGated Blood-Pool ImagingHeart Ventricles