<prompt> Best investigation for cardiac temponade is2-D EchocardiographyM-Mode EchocardiographyReal time echocardiographyUSG  <response>: A i.e. 2 D Echocardiography M- Mode Echo is also ka One dimensional echo, it uses stationary beam so informations are updated very rapidly. It is often more conventient for assessing distance motion of selected cardiac structure. 2-Dimensional echo has replaced it for most diagnostic purposes. It is expected that 3D imaging will replace most 2D imaging in future. 2-D-Echocardiography is investigation of choice for: Pericardial effusionQ Cardiac TemponadeQ Valvular hea ds Cardiomyopathy 