Clinical Study Of Acquired Long QT Syndrome In Patients With Chronic Kidney Disease

Background: Chronic kidney disease(CKD)is a group of chronic non-infectious diseases that are progressively developed.Due to their high incidence,high cost of treatment and poor prognosis,they have become a serious challenge for countries all over the world.Patients with chronic kidney disease have a high risk of fatal arrhythmias.Prolongation of QT interval is an independent risk factor for sudden cardiac death and increased all-cause mortality.Many studies have reported that patients with chronic kidney disease often have a prolonged QT interval,which may be a sign of increased cardiovascular mortality in this group of patients,but there are few studies on QT interval prolongation in patients with chronic kidney disease.Objective: To analyze the clinical features of acquired long QT syndrome(ALQTS)in hospitalized patients with CKD and to identify potential risk factors to improve clinical risk stratification in patients with CKD.Methods: This study retrospectively analyzed CKD patients who were hospitalized in the Dalian Medical University from September 2016 to October 2018 and had 12-lead ECG data.The clinical data were obtained in the electronic medical records.Exclusion criteria are as follows: 1.QT interval measurement and heart rate correction QT calculation: such as ectopic heart rhythm(atrial arrhythmia,ventricular arrhythmia,borderline escape heart rate,etc.),pacemaker carrying status,QRS time limit is greater than 120ms(complete left/right bundle branch block,indoor differential conduction),frequent ventricular premature beats/atrial premature beats,sinus tachycardia/slow tachycardia,pathological Q wave,etc;2.Diagnosis congenital length QT syndrome or family history;3.Hypertrophic cardiomyopathy,moderate to severe valvular stenosis or reflux,acute coronary syndrome,cardiac interventional surgery;4.Acute kidney injury,renal replacement therapy,blood potassium ? 6.5 Methyl/L;5.Other diseases or conditions known to cause prolongation of QT interval: liver disease,acute stroke,malignant tumor,hypothyroidism,application of drugs that can lead to prolongation of QT interval(drug type refers to www.crediblemeds.Org).Inclusion criteria: Each patient had an ECG result on the day of admission and 6 months of cardiac ultrasound and thyroid function results.Among them,12 lead electrocardiogram showed that QTc prolonged patients(male ? 450 ms,female ? 460ms)a total of 150 patients,QTc prolonged group,and patients with chronic kidney disease who were hospitalized and QTc interval normal were collected as normal group,and the normal group was followed.The ages ± 2,gender,and the main diagnosis were matched with the extended group.The control group enrolled a total of 298 patients.The age,gender,admission diagnosis,past history,family history,systolic blood pressure,diastolic blood pressure,creatinine(Cre),uric acid(UA),blood potassium(K),blood calcium(Ca),blood phosphorus(P)were recorded.),blood lipids(total cholesterol,triglycerides,HDL-C,LDL-C),hemoglobin(HB),albumin(ALB),24-hour urine protein quantification,BNP,and the like.Chi-square test,rank sum test,and logistic multivariate regression analysis were used to investigate the risk factors affecting QT interval prolongation.Results:1.A total of 150 patients in the extended group,including 9 patients with CKD1,9 patients with CKD2,14 patients with CKD3,21 patients with CKD4,and 97 patients with CKD5.After matching,there were 298 cases in the normal group.The chi-square analysis showed that there was a statistically significant difference in the distribution of CKD between the extended group and the normal group(P<0.001).2.Non-parametric test analysis showed: two groups of patients in QTc interval,hypertension,left ventricular hypertrophy,infection,creatinine,uric acid,HB,GFR,HDL,serum potassium,blood calcium,blood phosphorus,24-hour urine protein quantitation.There were statistical differences in the results of BNP and other results(P<0.05).3.Multivariate logistic regression analysis showed that glomerular filtration rate decreased,hypocalcemia and BNP were independent risk factors for QTc prolongation in patients with chronic kidney disease(P<0.05).Compared with CKD1-3,CKD stage 4(P=0.031,OR=4.609,95% CI=1.153-18.435),CKD stage 5(P=0.005,OR=7.085,95% CI=1.803-27.838)QTc interval The risk of prolongation was significantly increased;the risk of prolongation of QTc interval in patients with BNP >500 pg/ml was 2.329 times that of patients with BNP ? 500 pg/ml(P=0.044,OR=2.329,95% CI=1.022-5.305);blood calcium The risk of QTc interval prolongation in patients <2.02 mmol/L was 5.226 times that of patients with normal blood calcium(P<0.001,OR=5.226,95% CI=2.400-11.379).In conclusion:1.The prevalence of acquired long QT syndrome in patients with chronic kidney disease gradually increases with the decrease of GFR.2.Hypertension,left ventricular hypertrophy,infection,HB,HDL-C,24-hour increase in urinary protein and hyperphosphatemia are associated with prolonged QTc interval in patients with CKD.3.Decreased glomerular filtration rate,hypocalcemia and BNP are independent risk factors for QTc prolongation in patients with chronic kidney disease.