Do you know what you should be looking for to diagnose cardiac tamponade? The American Society of Echocardiography guideline on imaging in pericardial disease provides a useful summary of the evidence relating to the different signs (page 985 onwards).
For a practical overview of the signs, with example cases, the two videos below from Ultrasound Podcast, will keep you entertained.
This four part video from SonoSite shows you how to undertake the RUSH exam. In total the videos are around 1.25 hours in length.
For those who prefer reading to watching videos this publication describes the RUSH exam and how to perform it.
Bedside Ultrasound in Resuscitation and the Rapid Ultrasound in Shock Protocol- Review Article. Dina Seif, Phillips Perera, Thomas Mailhot, David Riley, and Diku Mandavia.
Critical Care Research and Practice. Volume 2012 (2012), Article ID 503254. http://dx.doi.org/10.1155/2012/503254.