Hayden Panettiere's Brother Jansen's Cause Of Death Revealed, Family Thanks 'Outpouring Of Love'

Actress Hayden Panettiere's brother Jansen Panettiere's cause of death was revealed Monday, more than a week after he was found dead in his apartment in Nyack, New York.

In a joint statement to ABC News, Jansen Panettiere's mother Lesley Vogel, father Skip Panettiere, and Hayden Panettiere revealed that the 28-year-old had died from an enlarged heart.

"Though it offers little solace, the Medical Examiner reported Jansen's sudden passing was due to cardiomegaly (enlarged heart), coupled with aortic valve complications," the family stated.

Cardiomegaly can be caused by damage to the heart muscle or any condition that makes the organ pump harder than usual, according to the Mayo Clinic.

Complications of aortic valve disease can include blood clots, stroke, heart failure, heart arrhythmias, and death due to sudden cardiac arrest.

A police report revealed friends of Jansen Panettiere became worried on Feb. 19 when the actor was scheduled to attend a meeting and never showed. A friend went over to his apartment and found him sitting upright in a chair and unresponsive.

The friend called 911 and began CPR. Jansen Panettiere was pronounced dead after first responders arrived. There were "no obvious signs of trauma," according to the report, and no foul play was suspected.

"Jansen's heart could be seen in his eyes, and his charm in his brilliant, engaging smile; his soul in his masterful and revealing paintings, and the joy of life in his dry wit," read a statement from the family.

"His charisma, warmth, compassion for others, and his creative spirit will live forever in our hearts and in the hearts of all whom he encountered."

The family also thanked those who shared words of encouragement.

"We sincerely appreciate the outpouring of love and support towards our family as we navigate this unthinkable loss, and ask that we be gifted our privacy during this time of mourning," the statement read. "We love you so much Jansen and you will be in our hearts forever."

Jansen Panettiere worked throughout his youth into adulthood, landing roles on "Blues Clues," "Even Stevens," "The X's," and "The Walking Dead."