Effect of amiodarone on the descending limb of the T wave.

Comparing patients treated after myocardial infarction with amiodarone or with placebo, we found a significant rate-dependent prolongation of TpTe interval in patients who received amiodarone. Patients who had arrhythmic death had significantly longer TpTe intervals than others on placebo but not on amiodarone. Assuming that TpTe reflects transmural repolarization heterogeneity, our findings suggest that heterogeneity and arrhythmic risk are increased by amiodarone. This contradicts the finding of decreased transmural repolarization heterogeneity by amiodarone and the appreciated antiarrhythmic efficacy of this drug.