Randy Travis has been hospitalized in critical condition since Sunday (July 7), and now a family member confirms the Grammy-winning singer has undergone heart surgery.

According to TMZ, Travis, 54, was airlifted to a Texas hospital on Sunday after his health began to deteriorate rapidly. Travis had been back on the road for the first time since recently completing a court-ordered rehab stemming from a 2012 drunk driving arrest when he came down with what he thought was a cold.

That turned out to be pneumonia, and on Monday (July 8) it was announced that Travis is suffering from viral cardiomyopathy, an infection of the heart muscles that is very serious and can lead to heart failure.

"We have been told he has had surgery," Travis' sister-in-law, Teresa Traywick, tells People magazine. "Our prayers are going out to him because my husband just had a heart attack last year, so it is in their family." Her husband is Travis' brother, Ricky Traywick.

"Their mother passed away at an early age with her heart, so it is like these boys are following right in their footsteps," she adds. "My prayers are with them. That's all I can say right now."