Usability research sometimes shows that people are ignoring reversed headings. When reading aloud, they will often just skip the heading as if they haven't noticed it. This is probably an example of the figure-ground illusion (often illustrated using the famous candlestick-faces diagram).
You can see this at work in typography when lists are printed this way.
But rather than dismiss reversed type as unusable, we should instead see this as a phenomenon we can use wisely to good effect. In fact it is most often used for navigation, where we are designing for a two stage reading process (find it, then read it). Here, we don't actually want everyone to read everything, so the figure-ground phenomenon actually supports the ignoring of irrelevant detail until the right section is found.
But just in case people do fail to read the headings, it's wise to repeat the content in the text that follows.