(A) In hearts from 5 sheep with tachypacing-induced
persistent AF, after at least 30 minutes of baseline AF, 10 μM ranolazine
was added to the perfusate for 15 minutes, followed by an increase in ranolazine
concentration to 20 μM for 15 minutes, and lastly the addition of
dofetilide (1 μM). The addition of dofetilide to ranolazine (20
μM) did not terminate persistent AF in any of the hearts, despite
decreasing average DF on the LA epicardium (* p<0.05
versus end of baseline). (B) The higher concentration of ranolazine
plus dofetilide did not significantly change average SP frequency on the LA
epicardium (p=n.s. versus end of
baseline).