Corrected QT interval in cirrhosis:A systematic review and metaanalysis

BACKGROUND Corrected QT(QTc)interval is prolonged in patients with liver cirrhosis and has been proposed to correlate with the severity of the disease.However,the effects of sex,age,severity,and etiology of cirrhosis on QTc have not been elucidated.At the same time,the role of treatment,acute illness,and liver transplantation(Tx)remains largely unknown.AIM To determine the mean QTc in patients with cirrhosis,assess whether QTc is prolonged in patients with cirrhosis,and investigate whether QTc is affected by factors such as sex,age,severity,etiology,treatment,acute illness,and liver Tx.METHODS In the present systematic review and meta-analysis,the searching protocol“{[QTc]OR[QT interval]OR[QT-interval]OR[Q-T syndrome]}AND{[cirrhosis]OR[Child-Pugh]OR[MELD]}”was applied in PubMed,EMBASE,and Google Scholar databases to identify studies that reported QTc in patients with cirrhosis and published after 1998.Seventy-three studies were considered eligible.Data concerning first author,year of publication,type of study,method used,sample size,mean age,female ratio,alcoholic etiology of cirrhosis ratio,Child-Pugh A/B/C ratio,mean model for end-stage liver disease(MELD)score,treatment withβ-blockers,episode of acute gastrointestinal bleeding,formula for QT correction,mean pulse rate,QTc in patients with cirrhosis and controls,and QTc according to etiology of cirrhosis,sex,Child-Pugh stage,MELD score,and liver Tx status(pre-Tx/post-Tx)were retrieved.The Newcastle-Ottawa quality assessment scale appraised the quality of the eligible studies.Effect estimates,expressed as proportions or standardized mean differences,were combined using the randomeffects,generic inverse variance method of DerSimonian and Laird.Subgroup,sensitivity analysis,and meta-regressions were applied to assess heterogeneity.RESULTS QTc combined mean in patients with cirrhosis was 444.8 ms[95%confidence interval(CI):440.4-449.2;P<0.001 when compared with the upper normal limit of 440 ms],presenting high heterogeneity(I2=97.5%;95%CI:97.2%-97.8%);both Egger’s and Begg’s tests showed non-significance.QTc was elongated in patients with cirrhosis compared with controls(P<0.001).QTc was longer in patients with Child-Pugh C cirrhosis when compared with Child-Pugh B and A(P<0.001);Child-Pugh B patients presented longer QTc when compared with Child-Pugh A patients(P=0.003).The MELD score was higher in patients with cirrhosis with QTc>440 ms when compared with QTc≤440 ms(P<0.001).No correlation of QTc with age(P=0.693),sex(P=0.753),or etiology(P=0.418)was detected.β-blockers shortened QTc(P<0.001).QTc was prolonged during acute gastrointestinal bleeding(P=0.020).Tx tended to improve QTc(P<0.001).No other sources of QTc heterogeneity were revealed.CONCLUSION QTc is prolonged in cirrhosis independently of sex,age,and etiology but is correlated with severity and affected byβ-blockers and acute gastrointestinal bleeding.QTc is improved after liver Tx.

Comparison of QT Correction Methods in the Pediatric Population of a Community Hospital: A Retrospective Study

Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formula has yet to be determined in the pediatric population,although it has intrinsically greater extremes in heart rate(HR)and is more susceptible to errors in measurement.The authors of this study compare six dif-ferent QTc methods(Bazett,Fridericia,Framingham,Hodges,Rautaharju,and a computer algorithm utilizing the Bazett formula)for consistency against variations in HR and RR interval.Methods:Descriptive Retrospective Study.We included participants from a pediatric cardiology practice of a community hospital who had an ECG performed in 2017.All participants were healthy patients with no past medical history and no regular med-ications.Results:ECGs from 95 participants from one month to 21 years of age(mean 9.7 years)were included with a mean HR of 91 beats per minute(bpm).The two-sample paired t-test or Wilcoxon signed-rank test assessed for any difference between QTc methods.A statistically significant difference was observed between every combination of two QTc formulae.The Spearman’s rank correlation analysis explored the QTc/HR and QTc/RR relationships for each formula.Fridericia method was most independent of HR and RR with the lowest absolute value of correlation coefficients.Bazett and Computer had moderate correlations,while Framingham and Rautaharju exhibited strong correlations.Correlations were positive for Bazett and Computer,reflecting results from prior studies demonstrating an over-correction of Bazett at higher HRs.In the linear QTc/HR regression analysis,Bazett had the slope closest to zero,although Computer,Hodges,and Fridericia had comparable values.Alternatively,Fridericia had the linear QTc/RR regression coefficient closest to zero.The Bland-Altman method assessed for bias and the limits of agreement between correction formulae.Bazett and Computer exhibited good agreement with minimal bias along with Framingham and Rautaharju.To account for a possible skewed distri-bution of QT,all the above analyses were also performed excluding the top and bottom 2%of data as sorted by heart rate ranges(N=90).Results from this data set were consistent with those derived from all participants(N=95).Conclusions:Overall,the Fridericia correction method provided the best rate correction in our pedia-tric study cohort.

Improvement of increased cQTd is associated with heart function in patients with ischemic heart failure

Background Chronic heart failure （CHF） is life-threatening without timely or effective intervention. In this study, we investigated the association between QT dispersion corrected for heart rate （cQTd） and heart function in patients with CHF. Methods From January 2013 to December 2015, we continuously enrolled 240 patients categorized as New York Heart Association functional class （NYHA） III-IV with a left ventricular ejection fraction （LVEF） 〈 40%. Based on the etiology, the patients were divided into a dilated cardiomyopathy （DCM） group （n = 120） and an ischemic cardiomyopathy （ICM） group （n = 120）. Then, based on the cQTd width, the ICM group was divided into two subgroups： a QS group （cQTd ≤60 ms, n = 70） and a QL group （cQTd 〉 60 ms, n = 50）. All patients were examined by echocardiography and 12-lead electrocardiography （ECG） at 1, 3, 6, and 12 months after enrollment. Results After one year of optimized medical treatment, patients in both groups showed significant improvement in LVEF and NYHA classification from baseline. However, the cQTd in the ICM group, especially the QL, was significantly shorter than that in the DCM group at each time point. In addition, the cQTd was negatively correlated with LVEF and 6-min walking test and positively correlated with NYHA class in the ICM group. Conclusions The present findings clearly demonstrate that cQTd is a meaningful parameter for assessing heart function in the follow-up of ICM patients.

Cirrhotic cardiomyopathy:Isn't stress evaluation alwaysrequired for the diagnosis?

AIM:To describe the proportion of patients with cirrhotic cardiomyopathy(CCM) evaluated by stress echocardiography and investigating its association with the severity of liver disease.METHODS:A cross-sectional study was conducted.Cirrhotic patients without risk factors for cardiovascular disease were included.Data regarding etiology and severity of liver disease(Child-Pugh score and model for end-stage liver disease),presence of ascites and gastroesophageal varices,pro-brain natriuretic peptide(proBNP) and corrected QT(QTc) interval were collected.Dobutamine stress echocardiography(conventional and tissue Doppler imaging) was performed.CCM was considered present when diastolic and/or systolic dysfunction was diagnosed at rest or after pharmacological stress.Therapy interfering with cardiovascular system was suspended 24 h before the examination.RESULTS:Twenty-six patients were analyzed,17(65.4%) Child-Pugh A,mean model for end-stage liver disease(MELD) score of 8.7.The global proportion of patients with CCM was 61.5%.At rest,only 2(7.7%)patients had diastolic dysfunction and none of the patients had systolic dysfunction.Dobutamine stress echocardiography revealed the presence of diastolic dysfunction in more 6(23.1%) patients and of systolic dysfunction in 10(38.5%) patients.QTc interval prolongation was observed in 68.8%of the patients and increased pro-BNP levels in 31.2%of them.There was no association between the presence of CCM and liver impairment assessed by Child-Pugh score or MELD(P= 0.775,P= 0.532,respectively).Patients with QTc interval prolongation had a significant higher rate of gastroesophageal varices comparing with those without QTc interval prolongation(95.0%vs 50.0%,P= 0.028).CONCLUSION:CCM is a frequent complication of cirrhosis that is independent of liver impairment.Stress evaluation should always be performed,otherwise it will remain an underdiagnosed condition.

Alpha-lipoic Acid:Effects on the Beat-to-Beat Vectorcardiographic Parameters in Type 2 Diabetes Mellitus Patients with Cardiac Autonomic Neuropathy

Objective:Relevance of cardiac autonomic neuropathy has not been fully recognized and there is no standardized treatment protocol.Aim:To evaluate the effects of alpha-lipoic acid on the beat-to-beat vectorcardiographic parameters,namely spatial QRS-T angle,QT dispersion(QTd)and corrected QT interval(QTc)in type 2 diabetes mellitus persons with cardiac autonomic neuropathy.Research designs and methods:Our study involved 33 persons with definite stage of cardiac autonomic neuropathy and diabetes mellitus type 2,which were assigned to each of two groups:one took standard antihyperglycaemic treatment(n=15,control group)and the other(n=18)in addition to standard therapy-600 mg of alpha-lipoic acid daily for three months.The analysis of vectorcardiographic parameters was performed.Results:It was found out that alpha-lipoic acid contributed to decrease of the vectorcardiographic parameters,namely QRS-T angle,QTd and QTc.Conclusions:The positive influences of alpha-lipoic acid suggest the usefulness of its prescription to type 2 diabetes mellitus persons with definite stage of cardiac autonomic neuropathy.The efficacy of alpha-lipoic acid is the result of its direct effect on the parameters of vectorcardiography.