Levosimendan is superior to epinephrine on coronary flow for lipid-base resuscitation of bupivacaine-induced asystole in the isolated rat heart

BACKGROUND: Successful resuscitation from asystole induced by bupivacaine requires the reestablishment of a sufficient coronary flow (CF) quickly. This study was designed to test whether levosimendan was superior to epinephrine in the reestablishment of crucial coronary flows after bupivacaine-induced asystole. METHODS: The isolated, perfused, nonrecirculating, Langendorff rat heart preparation was used. Bupivacaine 100 μmol/L was perfused into rat hearts to induce asystole, and then for 3 min thereafter. Three experimental groups were assessed after asystole with infusions as follow: (1) a mixture of 2% lipid emulsion and 40 μmol/L bupivacaine (control group), (2) a mixture of 0.15 μg/mL epinephrine combined with 2% lipid emulsion and 40 μmol/L bupivacaine (epinephrine group), and (3) a mixture of 5 μmol/L levosimendan combined with a 2% lipid emulsion and 40 μmol/L bupivacaine mixture (levosimendan group). Coronary flow (CF), the time to recovery (T(recovery)), the number of ventricular arrhythmias, and cardiac function parameters were recorded for 40 min after heartbeat recovery. RESULTS: All hearts in the control, epinephrine and levosimendan groups had heartbeat recovery. The rank order of the mean CF from highest to lowest was the levosimendan group > the epinepgrine group > the control group (P < 0.05). The rank order of T(recovery) from shortest to longest was the levosimendan group < the epinephrine group < the control group (P < 0.01). During the recovery phase, isolated rat hearts developed more ventricular arrhythmias in the epinephrine group than in the levosimendan group (P = 0.01). CONCLUSION: Levosimendan is superior to epinephrine in producing higher CFs and faster recovery when reversing bupivacaine-induced asystole in the isolated rat hearts.