Illinois Rep. Sean Casten, a Democrat, announced Friday that his daughter's death in June was from a cardiac arrhythmia.
"This past June, our daughter, Gwen Casten, died of a sudden cardiac arrythmia. In layman’s terms, she was fine, and then her heart stopped," the Casten family wrote in a statement.
Gwen Casten, 17, died peacefully in her sleep in June after eating dinner with her parents and then going out with friends for a few hours.
The congressman said after his daughter's passing that she had been looking forward to starting her freshman year at the University of Vermont this fall.
ILLINOIS REP. SEAN CASTEN REVEALS NEW DETAILS ABOUT DAUGHTER'S DEATH: ‘IT WAS PEACEFUL’
The family said Gwen was a healthy teenager who ate well, exercised, received regular medical check-ups, did not suffer from any behavioral issues and was close with friends and family.
She was fully vaccinated against COVID-19, the family said in their statement.
"We are heartbroken, but we are not unique," the statement read. "Sudden, unexplained heart-failure among young, healthy people is rare but real. We are left grasping at the wrong end of random chance."
The family said they are grateful for the "outpouring of love" they have received over the past few months.
ILLINOIS CONGRESSMAN SEAN CASTEN ANNOUNCES DEATH OF HIS 17-YEAR-OLD DAUGHTER
"We’ve cried again over each of your letters, messages, meals, and flowers, but they are appreciated. We are also grateful for the donations to the Downers Grove North Friends of Fine Arts and March for Our Lives, causes that Gwen was actively engaged in during high school. It is a comfort to know how many lives Gwen touched over her 17 years," the family wrote.
They recalled Gwen as having a big, beautiful, kind, loving heart.
"None of us know when our last heartbeat will come," the family wrote. "The best we can hope for is that when our loved ones do pass, we will have no regrets about the time we were lucky enough to share."
"So hug the folks you love a little harder today," they continued. "Be present in their lives. And spread your love a little farther. Because in the end, it’s all that remains."