Do you routinely use vasopressin in the management of RV failure leading to shock state in the absence of an obvious treatable cause such as infarction or PE?  

It seems that there is a vasopressin dose-dependent effect on PA pressures. The doses we usually use for septic shock (0.03 or less) have some degree of pulmonary vasodilation (for example, Tsuneyoshi et al., PMID 11373409). Higher doses may have the opposite effect (Leather et al., PMID 12441768). ...

I must say that I do not routinely use vasopressin for RV failure. Perhaps there is evidence supporting such a practice that I am not aware of.   I typically reserve use of vasopressin for septic shock with hypotension refractory to moderate dose norepinephrine infusion.