Re: DW: A big hand for the Doctor by Eoin Colfer Review Thread (Spoile
The first Doctor only having one heart is very much fanon - it might have been an assumption of the Virgin books, but it's just a theory, and you can take the onscreen evidence either way. For instance, when Ian says 'His heart's beating,', that could just be that he only checked for one heart, on the left, because it didn't occur to him to check that the Doctor might have another one on the right.
"Some days are better than others. They say that where I come from."
"Loudly, I imagine, on the day you left."
(Blake's 7 - Rumours of Death)