Methods of treating atrial arrhythmia include administering an effective amount of at least one antiarrhythmic pharmaceutical agent to a patient in need thereof, such that the at least one antiarrhythmic pharmaceutical agent first enters the heart through the pulmonary vein to the left atrium. Other methods of treating atrial arrhythmia include administering by inhalation an effective amount of at least one antiarrhythmic pharmaceutical agent to a patient in need thereof. An amount of the at least one antiarrhythmic pharmaceutical agent may peak in the coronary sinus of the heart at a time ranging from 10 seconds to 30 minutes from initiation of the administering. Unit doses, aerosols, and kits are also contemplated.