To explore the clinical characteristics and influencing factors of ECG QT interval prolongation in hospitalized patients with CKD stage 5.

Clinical data of the hospitalized patients with CKD stage 5 in the Department of Nephrology of the Second Hospital of Shanxi Medical University were collected retrospectively from January to December, 2018. By the pre-established criteria, the patients were divided into QTc prolongation group and normal group according to whether the QTc interval, which was corrected by the patient′s ECG in the stable state, was prolonged or not. The clinical characteristics of the two groups were compared and the related factors of QTc prolongation were analyzed. Logistic regression method was used to analyze the influencing factors of QTc prolongation in the patients.

A total of 310 patients were enrolled, including 178 males (57.4%) and 132 females (42.6%), among whom 130 cases were in the QTc prolongation group and 180 cases in the normal group. Compared with patients in the normal group, patients in the QTc prolongation group had higher age, higher proportion of infection and dialysis, lower values of serum albumin, HDL-C, potassium, and corrected calcium, together with higher level of the binding capacity of carbon dioxide. Color Doppler echocardiography showed that the left ventricular EF value was lower and the left atrial inner diameter was larger in the QTc prolongation group than in the normal group. There were no significant differences between the two groups in gender ratio, incidence of hypertension, incidence of coronary heart disease, incidence of diabetes, levels of hemoglobin, phosphorus, magnesium, LDL-C, and left ventricular inner diameter. Multivariate logistic regression analysis showed that hypocalcemia, serum potassium ≤4.0 mmol/L, and entering the stage of dialysis were the independent risk factors for prolonged QTc in the hospitalized patients with CKD stage 5.

The proportion of prolonged QTc of ECG in the hospitalized patients with CKD stage 5 was high. Hypocalcemia, serum potassium ≤4.0 mmol/L, and entering the stage of dialysis were independent risk factors for the prolonged QTc in the hospitalized patients with CKD stage 5.