Cardioplegics, known generically as Propafenone Hydrochloride Tablets, is an antiarrhythmic medication. The main effect of Propafenone Hydrochloride Tablets is to help maintain prolonged sinus rhythm in patients with chronic atrial fibrillation. Its side effects are mainly gastrointestinal or neurological and heart-related side effects. 1. Efficacy and effects (1)Increase the threshold potential of cardiomyocytes, reduce the spontaneous excitability of the myocardium, which is effective for all types of arrhythmia. (2)It is used to treat various arrhythmias complicated by preexcitation syndrome, and also used to prevent or treat ventricular or supraventricular premature exposures, ventricular or supraventricular tachycardia, etc. In addition, it has certain efficacy on arrhythmias caused by coronary heart disease and hypertension. 2.Side effects (1) Digestive system side effects: Propafenone Hydrochloride Tablets have mild side effects when taken orally, and the common side effects are digestive reactions, such as nausea, vomiting, metallic taste in the mouth or constipation. (2) Neurological and heart-related side effects: A few patients may experience neurological symptoms such as dizziness, irritability, and difficulty concentrating. Side effects such as atrioventricular block and bradycardia may occur when large doses are administered intravenously. Patients should follow the doctor’s instructions, do not adjust the dose or stop the drug, in order to avoid affecting the efficacy or side effects. Adverse reactions should seek medical advice and treatment under medical supervision.