Metoprolol tartrate, known generically as Betalucil, is taken only when sinus arrhythmia is combined with sinus tachycardia, or frequent ventricular premature line. Metoprolol tartrate belongs to the β-adrenergic receptor blocking drugs, the use of which can block the increase in sympathetic nerve activity, so that the heart rate slows down, but also able to reduce the pacemaker cell autoregulation, as well as to prolong the supraventricular conduction time; mainly used in the treatment of hypertension, angina pectoris, arrhythmia and other diseases. Sinus arrhythmia belongs to a type of arrhythmia, and if sinus arrhythmia is caused by physiological factors, it usually does not need to be treated; in addition, most of the sinus arrhythmia is combined with sinus bradycardia, so metoprolol tartrate is only taken when sinus arrhythmia is combined with sinus tachycardia, or frequent ventricular premature. Secondly, the drug may cause dizziness, headache, fatigue, diarrhea, abdominal pain and other discomforts after use; it is contraindicated for people with decompensated cardiac insufficiency, cardiogenic shock, sick sinus node syndrome, second or third degree atrioventricular block, and those who are allergic to the components of the drug; attention should be paid to the monitoring of blood pressure and hepatic and renal functions during the course of taking the drug, and for special groups of people, such as pregnant women and breastfeeding mothers, the medication needs to be used under the guidance of a doctor. All of the above medications should be used under the guidance of a doctor, avoid self-medication, in order to avoid adverse consequences.