Sinus heart rate refers to the state of heart rate in the physiological state of a normal person, so there is no pathological manifestation, and it is generally not dangerous, but pathological sinus node syndrome has the risk of sudden death. Normal adult sinus rhythm is about 60 to 120 beats per minute, originating from the sinus node, the sinus node beats once for every impulse issued by the heart, there is no manifestation of cardiac insufficiency such as panic attack and shortness of breath, and the electrocardiogram is visible as P, Q, R, and S waves. Sick sinus node syndrome will have sinus bradycardia, and there is a risk of syncope sudden death. However, sinus rhythm is not fixed, e.g., exercise, emotional excitement can increase the heart rate. Sinus arrhythmia has many causes, such as high blood pressure, coronary artery disease, and heart failure, and most are treated with medication under a doctor’s supervision. Consider medication or even pacemaker implantation for symptomatic sick sinus node syndrome. In case of chest tightness, palpitations, dizziness, blackouts, fainting, and weakness, it is recommended to seek medical attention as early as possible to avoid delays.