The 25-year-old, formerly of Celtic, fell to the ground clutching his chest in the first half of the Eredivisie encounter, but was able to walk off the pitch following treatment by a defibrillator.
"Evander had a cardiac arrest which was followed by a shock from his internal defibrillator," Feyenoord doctor Casper van Eijck told Reuters.
"And the shock is what he felt and that terrified him, which I could see in his eyes on the pitch.
"He was transported to a hospital because the defibrillator caused arrhythmia [an abnormal beat of his heart], so he has to stay there for the night."
Sno has a history of heart problems.