Electrocardiogram (ECG) reports sinus rhythm as a normal heart rhythm, p-wave widening suggests the possible existence of left atrial hypertrophy, and further examination is needed to confirm the diagnosis. Sinus rhythm and p-wave widening are all part of the description of an ECG test, and because the excitation of the heart begins in the sinus node, sinus rhythm is a normal heart rhythm. The p-wave on the ECG represents the atrium, when the p-wave prolongation time is more than 0.12s, it is called p-wave widening, which often suggests that the subject may have left atrial hypertrophy, but it can not confirm the diagnosis, and needs to be further perfected by the cardiac ultrasound, which is more diagnostic significance in diagnosing atrial hypertrophy. If the electrocardiogram describes p-wave widening and is accompanied by symptoms such as cardiac discomfort, it is recommended that the patient should consult a cardiologist in a timely manner.