Atrial Function, LeftAtrial FunctionAtrial Function, RightHeart AtriaEchocardiography, DopplerAtrial FibrillationEchocardiography, Doppler, PulsedElectric CountershockPericardiectomyMyocardial ContractionEchocardiographyHeart Function TestsEchocardiography, TransesophagealObserver VariationVentricular Function, LeftVentricular FunctionStroke VolumeBlood Flow VelocityHemodynamicsRisk AssessmentVentricular Function, RightHuman RightsVentricular Dysfunction, RightReproducibility of Results