Assertion: dissection | /r/CapableOf | involve the sac
Facets:
Source sentences:
text: In addition, after an initial tear causes a dissection, the dissection may spread and involve branching vessels, valves, or even the sac surrounding the heart.
text: If blood pressure is low, it may be an ominous sign--it could be that the dissection is involving the sac surrounding the heart or that the aorta has torn.