Symptoms of premature beats include palpitations, chest tightness, a brief sense of cardiac arrest, shortness of breath, fatigue, and in severe cases, dizziness. Premature beats, also known as preterm contractions, are electrical-mechanical activities of the heart caused by an impulse sent in advance from an ectopic pacing point other than the sinus node. Premature beats are a common clinical arrhythmia, and can be categorized into atrial premature beats, atrioventricular junctional premature beats and ventricular premature beats, with ventricular premature beats being the most common. Patients with no organic heart disease and occasional premature beats are often asymptomatic or only show palpitations, chest tightness, transient cardiac arrest, and shortness of breath and fatigue when the attacks are frequent; patients with underlying heart disease often have shortness of breath, chest tightness, fatigue, and in severe cases, dizziness and angina attacks. When patients have obvious symptoms, it is recommended to go to the hospital in time.