I wish I was at the library to pull some literature for you. But i'm out of town atm.
I do know of an old article that talks about this:
Warrington SJ, Padgham C, Lader M.
The cardiovascular effects of antidepressants.
Psychol Med Monogr Suppl. 1989;16:i-iii, 1-40.
PMID: 2690161
I was able to find it on PubMed. Unfortuneatly, I'm not an expert in this area so the only advice I can give is that the patient needs to be carefully monitored when started on any antidepressants. There are some new antidepressants in the market now, but they pretty much have the same mechanism of action, so the possiblity of varible BP is there. As to how much variablity there is, I have no idea.
This is a very good question, and I wish someone who's a Board Certified Psychiatric Pharmacist would answer this.
I would also recommend that the moderators move this thread to the Pharmacy Forums.