WWE Hall of Famer Bruno Sammartino's cause of death was revealed to be "multiple organ failure due to heart issues," according to Dave Meltzer of the Wrestling Observer Newsletter.

The wrestling legend died last week at the age of 82, having spent several months in the hospital. Meltzer also added that Sammartino's heart issues "dated back to his childhood," though the former World Champion wasn't aware of them.

Sammartino's funeral took place in Pittsburgh on Monday, with WWE chairman Vince McMahon among the many notable wrestling figures in attendance. Sammartino had heart surgery in 2011 and battled such issues for many years.

Before Hulk Hogan's rise in the '80s, Sammartino was arguably the biggest name in  the professional wrestling industry. The two-time WWWF World Heavyweight Champion began his career back in 1959, and quickly became one of the most popular wrestler in the '60s and '70s.

Sammartino's first World Championship reign lasted 2,803 days - far and away a WWE record that will never be topped. He held the championship for a record 4,040 days in just two reigns, too.

That's quite impressive for a superstar who battled health issues for much of his life. Meltzer also noted that Sammartino "nearly died from rheumatic fever," when he was only 12 years of age, which caused damage to his heart. Sammartino was also battling leg pain in his later years, but was able to hang on through it all, being the strong champion the world got to know and love.

Sammartino is survived by wife of 59 years and, three children and four grandchildren. He may be gone, but Sammartino completely changed the wrestling world and helped the WWE reach new heights many decades ago. For that, his legacy will never be forgotten.

NEXT: CODY RHODES COMMENTS ON WWE NETWORK BRUNO SAMMARTINO SPECIAL