I never read much Kaplan, seemed like a bloated text.
If I were you OP, I would get my hands on the Gravlee text on cardiopulmonary bypass. Your attendings will go over "hemodynamic goals" and for inducing cardiac patients (which is mostly handwringing over nothing anyway), but most probably won't talk to you about the heart lung machine. The heart lung machine and the surgery itself are the keys to a cardiac case. Whether or not to use isoflurane for myocardial preconditioning, all that stuff is crap.
That said, besides understanding cardiopulmonary bypass, the other most important thing is to understand the operation. Thus, reading a cardiac surgical textbook to understand the procedure is important. Clinicalkey gives you access to Kirklin I beleive, if your residency gives you access to that.