Long-term amiodarone administration protects against global myocardial ischemia.
 Reports on the effects of amiodarone on cardiac function have been variable.
 This study addresses the effect of long-term amiodarone administration on recovery of cardiac function after a period of global ischemia.
 Normotensive and spontaneously hypertensive rats were used.
 Normotensive rats (n = 6) received 240 mg/kg amiodarone for 4 weeks, for a total of 72 +/- 3 mg.
 Hypertensive rats (n = 6) received 500 mg/kg amiodarone for 4 weeks, for a total of 116 +/- 5 mg.
 Final myocardial concentrations of amiodarone and desethylamiodarone were 1.85 +/- 1.75 and 0.50 +/- 0.61 micrograms/g wet weight for the normotensive rats and 1.30 +/- 0.58 and 0.31 +/- 0.17 micrograms/g for the hypertensive rats (p = nonsignificant).
 Equal numbers of controls received sterile saline solution for 4 weeks.
 The hearts were excised and perfused in a Langendorff apparatus.
 The results indicate that, after 15 minutes of normothermic ischemia, hearts treated with this relatively low dose of amiodarone recovered a greater percentage of preischemic work (97% +/- 13%) as compared with the controls (76% +/- 17%) (p less than 0.005).
