I agree with the others, don't treat bigeminy. ...It's some kind of EMS lore that never seems to die that bigeminy is a terribly malignant rhythm and has to be squashed no matter what the consequences.
The meaning of the autumn equinox is intertwined with that of the four points of the year (the two solstices, and the spring equinox), which each mark stages in the esoteric work that begin anew each year, and form a symbolic cross in the wheel of the year, with the sun (Son/Christ) at the center.
The vernal equinox occurs on March 20 or 21 and the autumnal equinox on September 22 or 23, marking the beginning of spring and autumn, respectively, in the Northern Hemisphere (and the reverse in the Southern Hemisphere). The days on which an equinox falls have about equal periods of sunlight and darkness. Compare solstice.