Methods and kits for treating a cardiac arrhythmia using a platelet rich plasma (PRP) composition are provided. Any type of arrhythmia may be treated using the PRP composition. The PRP composition may comprise PRP developed using blood collected from a patient suffering the cardiac arrhythmia. The PRP composition may be buffered to a physiological pH and may include one or more anti-arrhythmic agents, anti-coagulants, or other drugs. The PRP composition may be delivered using a nebulizer, minimally invasively, or surgically.