This narrative engages the reader because it is such a change from the list that precedes it.
The reader moves from a list in lines 1-10 and then moves into the author's personal experience of tachycardia. This engages the reader because it is immediately interesting, and the reader wants to continue reading to find out how this attack connects to the larger theme of nature.
Furthermore, the language Oates uses features clear imagery -- we can easily imagine her lying there, on the ground. The effect is a powerful one and immediately interesting to the reader.
