Democratic Sen. Jack Gordon of Okolona was released after several hours of observation at a Jackson hospital Thursday.
Gordon said his heart rate jumped to an alarming speed after an hour-long morning exercise workout. He said he was treated with a defibrillator at University Medical Center.
Doctors then kept a watchful eye on him for three or four hours until they determined him fit for release.
Gordon has one of the highest-profile jobs in the Legislature. He served in the House from 1972-1980 and in the Senate from 1980-1992 and from 1996 until the present.