Atrial Function, LeftAtrial FunctionAtrial Function, RightHeart AtriaEchocardiography, DopplerAtrial FibrillationEchocardiography, Doppler, PulsedPericardiectomyElectric CountershockMyocardial ContractionHeart Function TestsEchocardiographyEchocardiography, TransesophagealVentricular Function, LeftVentricular FunctionObserver VariationStroke VolumeBlood Flow VelocityHemodynamics