Right atrial enlargement is usually due to pulmonary hypertension.

右心房增大通常由肺动脉高压引起。

In right atrial enlargement, depolarization of the right atrium lasts longer than normal and its waveform extends to the end of that of the left atrium.

右心房扩大时，右心房除极持续时间比正常长，波形延伸至左心房末端。