Amy Grant knew she had an irregular heartbeat, but she didn't know the underlying condition could trigger a serious cardiovascular event "sooner rather than later."

She found out about it in the most unexpected way. Talking to Good Morning America on Thursday (Aug. 13), Grant shares that she accompanied her husband, Vince Gill, for a routine visit to his cardiologist, who then started to inquire about how she was feeling. The doctor encouraged her to undergo some tests, and she learned she had a birth defect called partial anomalous pulmonary venous return, or PAPVR.

"They were doing an ultrasound of my heart and the doctor came in," Grant tells GMA's Robin Roberts. "He said, 'Vince, this is the kind of situation where Amy would be fine, fine, fine and then one day it would be catastrophic. And we don't know when that would be, but it would have been sooner rather than later."

So the 59-year-old Grant underwent heart surgery, which left her with a sizable scar from the bottom of her neck and down her chest.

Grant wants her fans and everyone to know that if something is wrong, they should address it. She says she's had the irregular heartbeat for 10 years, and at times it made it difficult to sing.

"I remember a couple times telling Vince, 'I feel like I'm suffocating.' It's the weirdest thing,'" she recalls in the interview.

Her recovery has been speedy since the surgery, and she hopes to return to singing live soon. In fact, the Christian singer is going to "sing to the day I die," she says. Always the optimist, she did find some silver lining around the clouds of this personal storm.

"I've never been big-breasted, and I almost feel like I have tattooed cleavage now," she says of her new scar, smiling and laughing. "This is like, awesome!"

Watch Amy Grant's Interview With GMA's Robin Roberts: 

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