Sinus arrythmia what is it and what is the treatment. My doctor has prescribed me cordarone (amiodarone) 100 mg once a day?

Sinus vrs Other. Likely u have other more serious arrhythmia. Sinus arrhythmia definition is a normal variation in a human being's pulse rate as it relates to respiratory actions. Most likely no tx is needed. Check this out http://www.She-health-living.Com/sinus-arrhythmia.Html.
Atrial fibrillation? Sinus node is the first organ inside your hear that is responsible for the heart rate. Sinus arrhythmia is when the rate set by the sinus node is no longer regular. Perhaps you have atrial fibrillation, that happens when the whole atrium chamber is fibrillating, creating an irregular rhythm of the heart, and Cordarone (amiodarone) would serve to revert it back to sinus rhythm.
Normal. Sinus arrhythmia is a condition where your heart rate changes more then normal when breathing in vs. Breathing out. The condition is actually perfectly normal. The medication you are taking is used to prevent mostly more dangerous ventricular arrhythmias. Most likely your dr. Saw something that put you at risk for this. Talk to him for more information.