Editor,—I read with interest the short case report by Betts and Radvan on the use of contrast echocardiography during pericardiocentesis.1 I would like to suggest a much simpler and cheaper method of differentiating pericardial space from a cardiac chamber during pericardiocentesis.

For the past 45 years I have always included an ampul of dehydrocholate and an ampul of lobeline on the sterile pericardiocentesis tray.2 Whenever the needle encounters blood or bloody fluid, one is faced with the problem of whether it is the …