"Hi guys, I came back to London to do some additional checks, and I'm very happy to say that my heart is absolutely fine and I'm completely healthy," Aubameyang said in an Instagram post.
"Really appreciate all the messages over the last few days and I'm already back at it."
An accompanying photograph showed him in the gym.
Aubameyang was released from quarantine last week but did not play against Ghana on Friday after doctors reported the cardiac lesions. Gabon teammate Mario Lemina, who plays for Nice, was also sent home for the same reason.
The player was stripped of the Arsenal captaincy in December after a disciplinary breach and has been linked to other clubs in the transfer window.