At their first point of contact with a VC, many entrepreneurs send their PowerPoint presentations instead of an executive summary.  This is a bad approach; PowerPoint presentations rarely function well as executive summaries.

Most PowerPoint presentations are designed to be verbally presented (these are called 'stand up' presentations).   Consequently, they tend to have few words on each slide to avoid distracting the audience.  However, because there is very little content on a good 'stand up' presentation slide, these documents make for very bad executive summaries.  All of the main insights that a presenter would traditionally say about the concept on each slide is absent when there's no one there to present them.  As a result, when VCs receive PowerPoint decks in lieu of a proper executive summary, they  miss the important information that someone would be saying in the background.   Usually, the message is lost.  In a lot of cases the slides don't have enough content to properly describe the product or service.   

Also, PowerPoint presentations tend to be long, whereas executive summaries are short.  With so many new plans to review each day, a VC is likely to give more attention to a document that they can digest in a few minutes.

In sum, be sure to send an executive summary that is in sentence/paragraph form.  Otherwise your chances of being asked in for a meeting will be decreased.