Amy Grant describes 'miraculous' recovery from open heart surgery

Singer Amy Grant is resting comfortably after undergoing "unanticipated open heart surgery."

The "Baby, Baby" singer, who underwent the procedure last week to correct a rare congenital defect, told her Instagram followers Monday that her recovery has "honestly felt miraculous."

Grant compared going into surgery to being "a non-runner who was signed up for a marathon," but added that support from her loved ones and fans felt like "this massive West Texas wind at my back... just pushing me through."

"Even stuff I was really scared about felt like nothing more than just a deep breath and something supernatural pushed me through it," she wrote. "And so I want to say thank you to each person who said a prayer for me. Prayer changes everything. Let's keep those prayers going for our country and lets [sic] turn all the brokenness into love and seeing each other."

Fans have known of Grant's heart condition for several months.

The 59-year-old first announced in February, in honor of Heart Health Awareness Month, that she had been diagnosed with the rare heart condition.

"I want to send a shout out to my doctor, John Bright Cage," the Christian singer told fans. "He suggested I have a check up because of my Dad's heart history."

Grant was happy she followed his advice and underwent a "battery of tests" that revealed she's unknowingly had partial anomalous pulmonary venous return, or PAPVAR, "since birth." PAPVR causes a mixing of oxygen-rich blood and oxygen-poor blood as it flows into the heart's right atrium instead of the left, because the pulmonary veins have incorrectly attached to the heart's upper right chamber, according to the Mayo Clinic.

The six-time Grammy winner happily assured fans that she was "asymptomatic" and that the heart condition was "fixable." She hoped that, by sharing her personal medical history, she would inspire fans to take their heart health more seriously.

ABC News' Lesley Messer contributed to this report.