I'd have to say a blood clot as the cause of death would be unlikely as embolic causes of death would almost certainly have been ruled out as the coronary, pulmonary and cerebral vessels are routinely examined at autopsy. Furthermore, for him to get an embolus in his brain secondary to a deep vein thrombosis he would need to have a hole in his heart.
SADS is what they call sudden death in the presence of structurally normal heart. The death is assumed to be due to a previously undiagnosed arrhythmia (irregular heart beat), which is not as uncommon as you might think. In my 200 student cohort at Uni we had two students diagnosed in a lab class one day, with potentially lethal arrhythmias, one requiring a pacemaker.










