Country superstar Randy Travis is in CRITICAL CONDITION after suffering from complications stemming from recently acquired viral cardiomyopathy ... this according to the singer's rep.

We're told the 54-year-old Grammy winner was admitted to a hospital in Texas yesterday. 

According to the Mayo Clinic, cardiomyopathy is a "disease that weakens and enlarges your heart muscle." Cardiomyopathy can lead to heart failure.

It's unclear what caused Travis' condition.

Travis was scheduled to perform in Deadwood, South Dakota on Wednesday. 

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