'Tis a Pity She's A Blog! 7

Special Effects are involved in the show. In the final act Giovanni enters his sisters bedroom and stabs her during a kiss. He then enters the banquet hall where everyone has gathered. On him he carries a knife, on which Annabella's heart is skewered. 

We can see here a contemporary staging of that portion.

A cost effective start to that effect can be found here.

http://www.videojug.com/webvideo/how-to-make-your-own-fake-bloody-heart

"How To Make Your Own Fake Bloody Heart (Props & Special Effects)." Videojug - Get Good At Life. The World’s Best How to Videos plus Free Expert Advice and Tutorials.Web. 09 Mar. 2011. <http://www.videojug.com/webvideo/how-to-make-your-own-fake-bloody-heart>.