Abstract: Objective To investigate the abnormalities of low QRS voltage (LQRSV)inelectrocardiogram (ECG) in patients with mental disorders and the influencing factors. 
Methods In total, 300 patients with mental disorders were selected as the research subjects, and their general data and abnormalities of LQRSV in ECG were collected to analyze the influencing factors of LQRSV abnormalities in ECG in patients with mental disorders. 
Results Of 300 patients with mental disorders, there were 120 cases (40.00%) of abnormal QRS voltage in ECG, including 65 cases (54.17%) of LQRSV in limb leads, 45 cases (37.50%) of LQRSV in chest leads, and 10 cases (8.33%) of LQRSV infull leads.All 120 patients with LQRSV abnormalities in ECG were accompanied by different abnormal ECG changes, such as sinus tachycardia, sinus arrhythmia, sinus bradycardia, preterm contraction, incomplete right bundle branch block, T-wave changes, ST-segment changes, Q-T interval prolongation, and left ventricular hypervoltage, which could be single or multiple manifestations. Duration of illness, age, duration of medication, dose index, and antipsychotics were all influencing factors for abnormal LQRSV in ECG in patients with mental disorders (P＜0.05). 
Conclusion Abnormal LQRSV in ECG in patients with mental disorders is as high as 40.00%, and age, duration of illness, duration of medication, dose index, and antipsychotics are the influencing factors of abnormal LQRSV in ECG in patients with mental disorders.

Key words: mental disorders, electrocardiography, QRS waves