Oakland Raiders Owner Al Davis Died Of A Broken Heart

The document reveals three primary causes of death: A) Ventricular fibrillation -- a dangerously abnormal heart rhythm B) Congestive heart failure C) Cardiomyopathy -- heart muscle disease

According to the death certificate, Al died at the Oakland Airport Hilton at 2:45 AM on October 8th.

The document shows Al had been diagnosed with cardiomyopathy years ago ... and suffered a ventricular fibrillation just 15 minutes before his death. Davis also suffered from Merkel cell carcinoma -- an aggressive form of skin cancer.

According to the doc, Davis -- who was involved with the NFL for 60 years -- underwent throat surgery just three days before his death. Davis also had heart surgery in 1996.