Hayden Panettiere talks about the sudden death of her brother Jansen

When Hayden Panettiere's younger brother died unexpectedly from an undiagnosed heart condition last year, the actress said it was like she had lost a part of herself.

“He was my only brother and it was my job to protect him,” she told People in an article published on Sept. 18. “When I lost him, it felt like I had lost half of my soul.”

Panettiere, 35, said her body reacted in a way she had never experienced before in the days following her brother's death.

“Within a few days, I was just bloated – bloated,” she said, adding that “stress and cortisol” can cause changes in the body.

The changes and the fact that she was being followed by paparazzi made her not want to leave her house anymore.

“I had to look at horrific paparazzi photos of myself coming out of Jansen's funeral, which was in a very private place, and it was shocking,” she said. “My agoraphobia came to the fore, which I've struggled with in the past.”

All of this contributed to a reduction in her self-esteem, she said.

“I didn't dare put anything on and leave the house, but I also knew I had to get out and keep moving or I would always look and feel like that,” she said.

She added: “It became a destructive hamster wheel of asking: Do I feel good enough to go out?”

The 'Bring It On' star eventually decided she wanted to go back to work, and she said everything changed when her publicist introduced her to her personal trainer.

“My body just started responding, not just through training. It allowed me to release the stress, the high expectations I had always placed on myself,” she said.

As she looks forward to the release of her next film, Amber Alert, she says she will never fully get over her brother's death.

“It will always break my heart. I will never get over it,” she said. “No matter how many years go by, I will never get over his loss.”

What happened to Jansen Panettiere?

Jansen Panettiere died of an enlarged heart on February 19, 2023, his family said in a statement to TODAY.com.

“It is with great sadness that we share the terrible, untimely loss of our beautiful Jansen,” the statement said. “While it is of little consolation, the medical examiner reported that Jansen's sudden death was due to cardiomegaly (enlarged heart) associated with aortic valve complications.”

Cardiomegaly, or enlarged heart, is not a disease in itself, but rather a sign of another condition, according to the Mayo Clinic. Heart damage and certain types of heart disease can cause the heart to become enlarged, according to the Mayo Clinic.

The Panettiere family did not provide details about the underlying cause of his illness, but said he was suffering from complications with his aortic valve.

These complications can occur when the aorta, the main artery that carries blood from the heart to the rest of the body, does not function properly, according to the Mayo Clinic.

“Jansen's heart was seen in his eyes, his charm in his bright, engaging smile; his soul in his masterful and insightful paintings and the joy of life in his dry wit,” his family said in the statement. “His charisma, warmth, compassion for others and creative spirit will live on forever in our hearts and in the hearts of everyone he met.”

“We are sincerely grateful for the love and support shown to our family as we process this unfathomable loss and ask that we be granted our privacy during this time of grief,” the family added. “We love you so much, Jansen, and you will be in our hearts forever.”

Jansen Panettiere was reportedly 28 years old at the time of his death. TODAY.com could not independently confirm his age.

He starred alongside his sister in films such as “Tiger Cruise” and “Racing Stripes” and also played the lead role in “Ice Age: The Meltdown” and the AMC series “The Walking Dead.”