[citation needed] Besides being indicated in arrhythmias, it was recommended as an alternative to amiodarone for the treatment of atrial fibrillation and atrial flutter in people whose hearts have either returned to normal rhythm or who undergo drug therapy or electric shock treatment i.e. direct current cardioversion (DCCV) to maintain normal rhythm.

[medical citation needed] The reduction in K current in some studies was shown to be due to the inhibition of the K-ACh channel or associated GTP-binding proteins.

[5][9] Dronedarone is a non-iodinated class III anti-arrhythmic drug which helps patients return to normal sinus rhythm.

[15] In the EURIDIS and ADONIS trials in atrial fibrillation (2007), dronedarone was significantly more effective than placebo in maintaining sinus rhythm, with no difference in lung and thyroid function in the short term.

[medical citation needed] In a later atrial fibrillation trial, ATHENA, with 4628 subjects, dronedarone was significantly more effective than placebo in reducing the composite endpoint of first hospitalization due to cardiovascular events or death.

[medical citation needed] The PALLAS trial (2011) was stopped for safety concerns due to the finding that "dronedarone increased rates of heart failure, stroke, and death from cardiovascular causes in patients with permanent atrial fibrillation who were at risk for major vascular events".

[18] A Black Box warning was subsequently added by the FDA stating that the risk of death, stroke, and hospitalization for congestive heart failure doubled in patients with permanent atrial fibrillation.

[17] The results of a recently concluded randomized study (ELECTRA) may clarify the safety and ideal modalities of dronedarone use at the time of cardioversion.

[citation needed] The approval is for "treatment of patients with a history of, or current atrial fibrillation to reduce their risk of cardiovascular hospitalization due to this condition.