Which plant causes cardiotoxicity involving altered peripheral circulation?

• A. hoary alyssum (berteroa)
• B. oak (quercus)
• C. kentucky 31 tall fescue (festuca)
• D. redroot pigweed (amaranthus)

Answer: (C)

Cardiotoxicity that involves altered peripheral circulation typically stems from potent vasoconstrictors that reduce blood flow to the extremities. Kentucky 31 tall fescue often harbors an endophytic fungus that produces ergot alkaloids. These compounds mimic sympathetic signaling and activate alpha-adrenergic and serotonergic receptors, causing marked constriction of peripheral blood vessels. The resulting decrease in peripheral perfusion can lead to cold, pale extremities and ischemic issues—hallmarks of vasoconstrictive or “vasospastic” cardiotoxic effects seen with fescue toxicosis.

The other plants listed are associated with different toxic effects: one tends toward anticoagulation and bleeding, another toward kidney injury, and the last can cause issues related to oxygen transport or other pathways, not the peripheral vasoconstriction pattern described.