GUILDERLAND — A man died after he lost consciousness while driving on Western Avenue Saturday, and crossed over into oncoming traffic, striking another vehicle before hitting a tree.

John J. Mellen, 53, of Rensselaer, was driving toward Albany on Western Avenue around 6:55 p.m. on Jan. 30, when he lost consciousness due to a medical condition, and swerved into the westbound lane, said Curtis Cox, captain of the Guilderland Police Department.

While Mellen may have suffered a heart attack, Cox said autopsy results, not as yet available, would be needed to make that determination.

Mellen’s 1992 Buick Roadmaster struck a 2004 Oldsmobile driven by Regina M. Pasa, of Davenport (Delaware County). Mellen’s car then went over the curb and hit a tree, Cox said.

Mellen was transported to Albany Medical Center by the Western Turnpike Rescue Squad, and was pronounced dead at the hospital. Pasa and the passenger in her car were not injured, said Cox.