(CNN) -- Randy Travis's publicist denied media reports that the country singer had heart surgery, but he did say Tuesday that Travis received a device to help blood flow.
Travis, 54, was admitted to an unidentified Texas hospital on Sunday because of complications related to his "recently acquired viral cardiomyopathy," Travis spokesman Kirt Webster said in a written statement.
Travis remained in critical condition Tuesday, Webster said.
The singer "underwent the placement of an Impella peripheral left ventricular assist device for stabilization prior to transferring hospitals."
The Mayo Clinic's website described the device as "an implantable mechanical pump that helps pump blood from the lower chambers of your heart to the rest of your body."
Travis had recently been on the road, performing in Detroit on June 28 and Chicago on June 29. He was set to do a show in Deadwood, South Dakota, on Wednesday.
He appeared well during business meetings on Friday and Saturday, Webster said. "Then on Sunday, it hit him."
Viral cardiomyopathy is a disorder where a virus attacks the muscles of the heart, causing the heart to beat slower, according to the U.S. Centers for Disease Control and Prevention's website. In some cases, the heart can stop, it said.
"Viral cardiomyopathy can be caused by 30-plus different viruses, but it's almost impossible to pinpoint which virus it is," said Dr. Ramin Oskoui, a cardiologist and internal medicine specialist in Washington. "Hospitals use viral cardiomyopathy as a 'catch all' diagnosis."
"To say that Mr. Travis' alcohol use exacerbated his problems would be pure speculation, but if someone told me alcohol played a role in his cardiac problems, I wouldn't be surprised," Oskoui said.
Travis was at the forefront of the "New Traditionalist" movement in the 1980s and 1990s, but he faded as the '90s wore on. He made a comeback after turning to gospel music in 1999. His song "Three Wooden Crosses" won song of the year in 2003 from both the Country Music Association and the Academy of Country Music.
As one of country music's top-selling artists, Travis has won seven Grammys, 10 Academy of Country Music awards and 10 American Music Award statuettes.
His best-known songs also include "Forever and Ever, Amen," "Diggin' Up Bones" and "Deeper Than the Holler."
CNN's Carolyn Sung, Todd Leopold, Val Willingham and Denise Quan contributed to this report.