OBJECTIVE: To probe into the risk factors of prolonged QT interval of electrocardiogram in hospitalized patients in department of cardiovascular medicine in a certain Grade Ⅲ Level A hospital（ hereinafter referred to as"this hospital"）. METHODS: The data of all hospitalized patients in the department of cardiovascular medicine in Jan. 2019 were collected from HIS system of this hospital for a cross-sectional study

and a multivariate logistic regression model was used to explore the risk factors affecting the QT interval level. RESULTS: The multivariate logistic regression analysis indicated that among the hospitalized patients in department of cardiovascular medicine

the corrected QT interval（ QTc） >450 ms（ P =0. 001） and application of risky drugs（ P =0. 012） were the risk factors of prolonged QT interval during hospitalization; female（ P = 0. 149）

age ≥68 years（ P = 0. 271）

hypokalemia at admission（ P = 0. 717）

acute myocardial infarction（ P = 0. 132） and heart failure（ P = 0. 226） were not related to the prolonged QT interval during hospitalization. CONCLUSIONS: Among the hospitalized patients in department of cardiovascular medicine

factors of hypokalemia

age ≥ 68 years

female and concomitant diseases at admission were not significantly correlated with acquired long QT syndrome（ ALQTS）

the application of risky drugs and QTc > 450 ms at admission were the important risk factors that caused the prolonged QT interval. For people at high risk of ALQTS

drugs without the risk of prolonged QT interval should be used rationally to reduce the occurrence of prolonged QT interval.