alternation in cardiac activities of either the systemic or the pulmonary circulation, but not of both, or in both but oppositely directed in each.
dis·cor·dant al·ter·na·tion
(dis-kōr'dănt awl'tĕr-nā'shŭn) Alternation in cardiac activities of either the systemic or the pulmonary circulation, but not of both, or in both but oppositely directed in each.