Michael Madsen’s cause of death has been confirmed less than a week after the “Reservoir Dogs” star was found unresponsive in his Malibu home on July 3.

The 67-year-old actor died of heart failure, with heart disease and alcoholism identified as contributing factors, Madsen’s cardiologist told NBCLA. Authorities do not suspect foul play in his death, which has been attributed to natural causes.

Given that the doctor has already signed the death certificate and was treating the “Donnie Brasco” alum, an autopsy will not be performed.

His manager Ron Smith told the outlet last week that Madsen died from cardiac arrest.

Insiders told TMZ this week that the frequent Quentin Tarantino collaborator, who was also a published poet, got sober in recent months. Loved ones reportedly hope Madsen, who long battled substance abuse, “was still working his program” at the time of his death.

Madsen’s Oscar-nominated younger sister Virginia Madsen remembered him as “half legend, half lullaby.”

A father of seven, Madsen’s son Hudson preceded him in death when the 26-year-old died by suicide in early 2022.

Of his nearly 350 screen credits, Madsen’s most memorable roles were those in Tarantino’s films such as “Reservoir Dogs,” both volumes of “Kill Bill,” “The Hateful Eight” and “Once Upon a Time… in Hollywood.” He also appeared in “WarGames” and “Species.”

©2025 New York Daily News. Visit nydailynews.com. Distributed by Tribune Content Agency, LLC.