Abstract: AIM To investigate the relationship between arrhythmia and clinically relevant factors in patients with different types of coronary heart disease (CHD). METHODSA total of 1014 CHD patients were enrolled and divided into acute coronary syndrome (ACS) group and chronic ischemic syndrome (CIS) group. HOLTER was used to record the types of arrhythmia. Relation of occurrence of atrial arrhythmia or ventricular arrhythmia in both groups and number of coronary artery lesions, serum potassium, BNP, left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVEDD) were analyzed. Risk factors of arrhythmia were examined by logistic regression analysis. RESULTSIn ACS group, no significant differences were observed in the number of coronary artery lesions, BNP, LVEF and LVEDD between atrial arrhythmia or ventricular arrhythmia, but there was a significant difference in the serum potassium value between atrial arrhythmia or ventricular arrhythmia occurring in the group (P<0.05). Logistic regression analysis revealed that hypokalemia (P=0.027, OR: 2.009, 95% CI: 1.084-3.726) was an independent risk factor for ventricular arrhythmia occurring in the group. In CIS group, no significant differences were found in the number of coronary artery lesions and serum potassium value between atrial arrhythmia or ventricular arrhythmia, but there were significant differences in BNP, LVEF and LVDD between atrial arrhythmia or ventricular arrhythmia (P<0.05). Logistic regression analysis revealed that lower LVEF (P=0.048, OR: 3.561, 95%CI: 1.01-12.553) was an independent risk factor of ventricular arrhythmia occurring in this group. CONCLUSIONVentricular arrhythmia is more likely to occur in ACS patients with hypokalemia and in CIS patients with higher BNP and LVDD and lower LVEF. Hypokalemia may be a risk factor of ventricular arrhythmia for ACS patients, and lower LVEF may be a risk factor for ventricular arrhythmia for CIS patients.