A detained Saudi royal who was swept up in a 2018 crackdown recently suffered a heart attack while under house arrest in Riyadh, sources close to the family said on Tuesday. Abdulaziz Al Saud and his son Salman have been held for six years without formal charges since Crown Prince Mohammed bin Salman led a clampdown on critics and rivals from within the ruling family six years ago. On Friday, Prince Abdulaziz was taken to hospital with a heart attack, said a source close to the family who spoke on condition of anonymity for fear of reprisal. He returned to his residence in the capital three da…