3:01 PM PT -- According to county records, Artem Chigvintsev was released at 2:18 PM PT.

We now know how the alarm was sounded when someone at Artem Chigvintsev's home called 911.

Sources connected to the investigation tell TMZ ... a call came in around 8:30 AM, reporting a "medical emergency" at the home. It's unclear who made the call.

As paramedics and the fire department were en route, someone from the house called 911 again to cancel the request. They did not say why, but we're told paramedics and fire returned to their stations ... never showing up at the house.

At 10 AM, Artem was arrested for felony corporal injury to spouse or cohabitant. In order to make the arrest for a felony, the injury must be visible.

Artem is married to Nikki Garcia -- better known as Nikki Bella in WWE circles -- but the name of the alleged victim has been withheld.

Artem and Nikki celebrated their second wedding anniversary this week.

If you or someone you know is affected by any of the issues raised in this story, call the National Domestic Violence Hotline at 1-800-799-SAFE (7233) or text START to 88788.