The Annals of Thoracic Surgery, Vol 50, 575-578, Copyright © 1990 by The Society of Thoracic Surgeons
Long-term amiodarone administration protects against global myocardial ischemia
JA Karlson, RW Hopkins, JM Moran and KE Karlson
Brown University, Providence, RI.
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).