Myocardial Repolarization Research Articles

The dispersion of myocardial repolarization in ischemic stroke and intracranial hemorrhage

BackgroundMarkers of dispersion of myocardial repolarization have been proposed to identify the patients at higher risk of malignant arrhythmic events. The aim of the present study is to assess a possible association of the electrocardiografic (ECG) markers of the dispersion of repolarization with the type of stroke, involvement of insula, neurological severity (National Institutes of Health Stroke Scale, NIHSS score), and disability (modified Rankin Scale, mRS score) in patients with a cerebrovascular event. MethodsWe conducted a retrospective analysis based on data prospectively collected from consecutive patients with a cerebrovascular event who underwent 12‑lead ECG at admission to the Verona Stroke Unit. ResultsOf the 63 patients included in the study, 55 had ischemic stroke and 8 intracranial hemorrhage. TpTe (time between the peak and the end of the T wave) and TpTe/QTc (TpTe/corrected time between the start of the Q wave and the end of the T wave) in lead V5 were higher in intracranial hemorrhage than in ischemic stroke (p = 0.03 and p = 0.04, respectively) and QT max (the longest QT calculated in the 12 leads) was higher in patients with involvement of insula (p ≤ 0.01). A correlation was found between QTc max and NIHSS score at admission (p = 0.02), QT max and NIHSS score at discharge (p = 0.05), and QT max and mRS score at discharge (p = 0.02). ConclusionsTpTe and TpTe/QTc in V5 lead were associated with intracranial hemorrhage and QT max was associated with involvement of insula. The prolongation of QT was correlated with neurological severity and disability.

Mutation of the Na+/K+-ATPase Atp1a1a.1 causes QT interval prolongation and bradycardia in zebrafish

The genetic underpinnings that orchestrate the vertebrate heart rate are not fully understood yet, but of high clinical importance, since diseases of cardiac impulse formation and propagation are common and severe human arrhythmias. To identify novel regulators of the vertebrate heart rate, we deciphered the pathogenesis of the bradycardia in the homozygous zebrafish mutant hiphop (hip) and identified a missense-mutation (N851K) in Na+/K+-ATPase α1-subunit (atp1a1a.1). N851K affects zebrafish Na+/K+-ATPase ion transport capacity, as revealed by in vitro pump current measurements. Inhibition of the Na+/K+-ATPase in vivo indicates that hip rather acts as a hypomorph than being a null allele. Consequently, reduced Na+/K+-ATPase function leads to prolonged QT interval and refractoriness in the hip mutant heart, as shown by electrocardiogram and in vivo electrical stimulation experiments. We here demonstrate for the first time that Na+/K+-ATPase plays an essential role in heart rate regulation by prolonging myocardial repolarization.

Electrocardiographic changes after high-dose corticosteroid pulse therapy in pemphigus patients

Purpose: The objective of the current study was to evaluate the effect of intravenous methylprednisolone pulse therapy on myocardial repolarization alterations, especially QT dispersion in anticipation of cardiovascular risks in patients with pemphigus vulgaris.Methods: The current study is a prospective-controlled study on the electrocardiographic changes after methylprednisolone pulse therapy in 50 patients with pemphigus vulgaris.Results: A total of 50 patients (28 female and 22 male) were included in our study. The mean heart rate was significantly higher in male patients both before (92 ± 10.80 versus 82.75 ± 12.01 ms) and after pulse therapy (102.73 ± 14.26 versus 91.07 ± 15.02 ms) (p value < .01). The value of heart rate was significantly greater after receiving steroid pulse therapy. Corrected QT dispersion before pulse therapy was 19.92 ± 8.2 ms that increased to 40.68 ± 18.12 ms after treatment (p value < .001).Conclusion: Our study shows that there is a relationship between pulse steroid infusion and increased predisposition to the occurrence of cardiac arrhythmias. QT dispersion could be a good marker to assess this risk in these patients.

Evaluating the risk of QTc prolongation associated with antidepressant use in older adults: a review of the evidence.

Antidepressants are widely used medications for a range of medical conditions such as mood disorders and chronic pain in older adults. A vast body of evidence exists concerning the risks of QT interval prolongation associated with these agents and healthcare providers should critically evaluate the potential for QT prolongation when selecting antidepressant agents. Long QT syndrome is a disorder of myocardial repolarization that manifests as a prolonged QT interval on an electrocardiogram (ECG) and has been demonstrated to increase with age. The objective of this review is to present and evaluate existing literature regarding the risk of QT prolongation in older adults, age 60 years and older, and discuss the implications for clinical practice. A PubMed search was conducted to identify studies evaluating the QT prolonging effects of antidepressant medications and publications were chosen based on pertinent criteria. Depending on the antidepressant agent and patient-specific factors, clinicians should assess and monitor electrolytes and EGCs to evaluate the risks and benefits for older adults receiving agents known to prolong the QT interval.

Maturation of the QT Variability Index is Impaired in Preterm Infants

Reduced heart rate (HR) variability in preterm infants compared with full-term infants suggests that autonomic cardiac control is developmentally delayed. However, the association between developmental changes in myocardial repolarization and gestational age remains unknown. This study investigated the association between the myocardial repolarization lability index, namely the QT variability index (QTVI) = log10 [(QTv/QTm2)/(HRv/HRm2)], and the perinatal profile of healthy 1-month-old infants. We included 209 infants (143 boys and 87 girls; mean gestational weeks at birth, 38.6 ± 1.7) who were born in university hospitals between 2014 and 2015 without apparent cardiac disease. We compared the ECG variability indices in 28 infants born before 37 gestational weeks (mean gestational weeks at birth, 35.6 ± 1.1 as preterm) and 181 infants born at the average number of gestational weeks (mean gestational weeks at birth, 38.8 ± 1.1 as controls). There was a negative correlation between the QTVI and gestational weeks (r = − 0.460, p = 0.035). QTVI values in preterm infants were larger than those in the controls (0.01 ± 0.50 vs. −0.26 ± 0.48, p = 0.023). In conclusion, the QTVI is negatively correlated with gestational age. The QTVI can serve as an index of the maturity of the cardiac autonomic nervous system and myocardial depolarization.

Myocardial repolarization is affected in patients with ascending aortic aneurysm

ObjectiveAscending aortic aneurysm (AAA) is one of the major causes of ventricular diastolic dysfunction. Diastolic dysfunction can induce ventricular repolarization dispersion. Nevertheless, myocardial repolarization dispersion is not yet to be fully evaluated in patients with AAA. We aimed to evaluate ventricular repolarization using QT and Tp-Te interval and corrected (c) Tp-Te/QT ratio in patients with AAA. MethodsOne hundred-four patients with AAA without coronary artery disease (CAD) served as the aneurysm group and 82 patients having a normal aortic diameter as the control group. All patients underwent transthoracic echocardiography (TTE) for measurements of LV diastolic function and underwent electrocardiography (ECG) to calculate RR, QT, Tp-Te intervals and QT dispersion. Bazett's formula was used to calculate QTc and cTp-Te intervals. cTp-Te/QT ratio was also calculated. ResultsThe groups were similar according to basal characteristics. We found left ventricular diastolic properties were impaired and QT dispersion, QTc interval, and both of Tp-Te and cTp-Te intervals were significantly prolonged in the aneurysm group than the control group. There were also significant correlations between TTE and ECG parameters. On multivariate linear regression analysis, indexed ascending aortic dimension (AAoD), LA diameter and E/e′ ratio were independent predictors of ventricular repolarization dispersion in AAA patients. ConclusionsOur study results showed that patients with AAA may have an increased risk for ventricular arrhythmogenesis because of deteriorated the left ventricular diastolic function.

Is There any Relationship Between Myocardial Repolarization Parameters and the Frequency of Ventricular Premature Contractions?

BackgroundVentricular premature contractions (VPCs) may trigger lethal ventricular arrhythmias in patients with structural heart disease. However, this role of VPCs in healthy people remains controversial once that not enough clinical trials are available. Recently, some myocardial repolarization markers, such as Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios, have been reported to be useful for predicting lethal ventricular arrhythmias in various clinical disorders without structural heart disease.ObjectiveIn this study, we aimed to investigate the relation between VPC frequent and myocardial repolarization markers in individuals without structural heart disease.MethodsThis study included 100 patients who had complaints of dizziness and palpitations. Twelve-lead electrocardiography and 24-hour ambulatory Holter recordings were obtained from all patients. VPC burden was calculated as the total number of VPCs divided by the number of all QRS complexes in the total recording time. P-values < 0.05 were considered significant.ResultsTp-e interval and Tp-e/QTc ratio were significantly higher in patients with higher VPC burden than in patients with lower VPC burden, and a positive correlation was found between these markers and VPC burden. Tp-e (β = 1.318, p = 0.043) and Tp-e/QTc (β = -405.136, p = 0.024) in the lead V5 were identified as independent predictors of increased VPC burden.ConclusionsTp-e interval and Tp-e/QTc ratio increased in patients with high VPC number. Our study showed that VPCs may have a negative effect on myocardial repolarization. This interaction may lead to an increased risk of malignant arrhythmias.

The assessment of P-wave dispersion and myocardial repolarization parameters in patients with chronic kidney disease

Objective: The risks of sudden death and cardiac arrhythmia are increased in patients with chronic kidney disease (CKD). Here, we aimed to evaluate the indicators of arrhythmias, such as p-wave dispersion (P-WD), QTc dispersion, Tp-e and Tp-e/QT ratio in patients with CKD stages 3–5 on no renal replacement therapy (RRT). Material and methods: One-hundred and thirty three patients with CKD stages 3–5 and 32 healthy controls were enrolled into the study. No patients received RRT. QTc dispersion, P-WD and Tp-e interval were measured using electrocardiogram and Tp-e/QT ratio was also calculated. Results: Mean age rates were found similar in patients and controls (60.8 ± 14.2 and 61 ± 12.9 y, p = .937, respectively). Compared patients with controls, P-WD (45.85 ± 12.42 vs. 21.17 ± 6.6 msec, p < .001), QTc-min (366.99 ± 42.31 vs. 387.15 ± 20.5 msec, p < .001), QTc dispersion (71.13 ± 27.95 vs. 41.25 ± 14.55 msec, p < .001), Tp-e maximum (81.04 ± 10.34 vs. 75.49 ± 10.9 msec, p < .001), Tp-e minimum (62.25 ± 7.58 vs. 54.8 ± 6.72 msec, p < .001) and Tp-e/QTc ratio (0.19 ± 0.02 vs. 0.18 ± 0.01, p = .001) were found to be different. QTc-max and Tp-e interval were found to be similar in both groups. Conclusion: P-WD and QTc dispersion, Tp-e interval and Tp-e/QTc ratio were found to be increased in with CKD stages 3–5 on no RRT.

Repolarization in perfused myocardium predicts reperfusion ventricular tachyarrhythmias

BackgroundAim of the study was to find out which myocardial repolarization parameters predict reperfusion ventricular tachycardia and fibrillation (VT/VF) and determine how these parameters express in ECG. MethodsCoronary occlusion and reperfusion (30/30min) was induced in 24 cats. Local activation and end of repolarization times (RT) were measured in 88 intramyocardial leads. Computer simulations of precordial electrograms were performed. ResultsReperfusion VT/VF developed in 10 animals. Arrhythmia-susceptible animals had longer RTs in perfused areas [183(177;202) vs 154(140;170) ms in susceptible and resistant animals, respectively, P<0.05]. In logistic regression analysis, VT/VFs were associated with prolonged RTs in the perfused area (OR 1.068; 95% CI 1.012–1.128; P=0.017). Simulations demonstrated that prolonged repolarization in the perfused/border zone caused precordial terminal T-wave inversion. ConclusionsThe reperfusion VT/VFs were independently predicted by the longer RT in the perfused zone, which was reflected in the terminal negative phase of the electrocardiographic T-wave.

Is myocardial repolarization duration associated with repolarization heterogeneity?

Dispersion of repolarization is theorized as one mechanism by which myocardial repolarization prolongation causes lethal torsades de pointes, (TdP). Our primary purpose was to determine whether prolongation of myocardial repolarization as measured by the heart rate-corrected J-to-T peak interval (JTpkc), is associated with repolarization heterogeneity as measured by transmural dispersion, defined as the median duration from the peak to the end of the T wave (TpTe). A retrospective cohort study was performed at a single urban tertiary ED from July 2011-September 2012. Inclusion criteria included all consecutive ED patients with ECG based on QTc and QRS intervals. Automated measurements of all intervals were performed. The association of JTpkc with the dependent variable TpTe was assessed after adjustment for QRS and RR interval durations with a multiple linear regression model. A secondary analysis included a similar adjusted assessment of the association of JTpkc with QT dispersion, QTd. Finally, we constructed two multiple regression models to assess the association of clinical causative factors of TdP with TpTe and JTpkc. Eight hundred seventy-four cases were included: 186 with QTc <500ms, 118 with QTc ≥500 and QRS ≥120ms, and 570 with QTc ≥500 and QRS <120ms. The coefficient for association of JTpkc with TpTe was -0.10 (95%CI -0.15 to -0.05), and for JTpkc with QTd was 0.03 (95% CI -0.01 to 0.06). Clinical causative TdP factors were associated more with JTpkc than TpTe. Repolarization duration as measured by JTpkc is not positively associated with dispersion of repolarization as measured by TpTe or QTd. Dispersion of repolarization may not be a critical mechanistic link between QTc prolongation and TdP.

073_16967-M1 Evaluation of Tp-e Interval and Tp-e/QTc Ratio in Patients with Heart Transplantation

The number of patients with heart transplantation has dramatically increased in the last decade. There is, however, no sufficient data regarding arrhythmic risk in such patients. To discuss this issue, in the current study we analyzed dispersion of myocardial repolarization using Tp-e interval and

The importance of frontal QRS-T angle for predicting non-dipper status in hypertensive patients without left ventricular hypertrophy

ABSTRACTBackground: Frontal QRS-T angle is a novel marker of myocardial repolarization, and an increased frontal QRS-T angle associated with adverse cardiac outcomes. Non-dipper hypertension is also associated with adverse cardiac outcomes. This study aimed to investigate the relationship between frontal QRS-T angle and non-dipper status in hypertensive patients without left ventricular hypertrophy (LVH).Methods: This study included 122 hypertensive patients without LVH. Patients were divided into two groups: dipper hypertension and non-dipper hypertension. The frontal QRS-T angle was calculated from 12-lead electrocardiography.Results: Frontal QRS-T angle (47.9° ± 29.7° vs. 26.7° ± 19.6°, P < 0.001) was significantly higher in patients with non-dipper hypertension than in patients with dipper hypertension. In addition, frontal QRS-T angle was positively correlated with sleeping systolic (r = 0.211, P = 0.020), and diastolic (r = 0.199, P = 0.028) blood pressures (BP), even if they were weak. Multivariate analysis showed that the frontal QRS-T angle was independent predictor of non-dipper status (QR: 1.037, 95% CI: 1.019–1.056, P < 0.001).Conclusion: Frontal QRS-T angle is independent predictor of non-dipper status in hypertensive patients without LVH.

Assessment of myocardial repolarisation parameters in patients with familial Mediterranean fever.

SummaryBackground:Familial Mediterranean fever (FMF) is a chronic, recurrent auto-inflammatory disease characterised by self-terminating attacks of fever and sterile polyserositis. The main cause of death in auto-inflammatory diseasesis cardiovascular events. Additionally, auto-inflammatory diseases have potential effects on the myocardial repolarisation parameters, including the T-wave peak-to-end (Tp-Te) interval, cTp-Te interval (corrected Tp-Te) and the cTp-Te/ QT ratio. The aim of this study was to analyse the efficacy of myocardial repolarisation alterations in anticipation of cardiovascular risks in patients with FMF.Methods:This study included 66 patients with FMF and 58 healthy control subjects. Tp-Te and cTp-Te intervals and the cTp-Te/QT ratio were measured from the 12-lead electrocardiogram.Results:In electrocardiographic parameters, analysis of QT, QT dispersion, corrected QT (QTc) and QTc dispersion were similar between the groups. The Tp-Te and cTp-Te intervals and Tp-Te/QT and cTp-Te/QT ratios were significantly prolonged in FMF patients. Multivariate linear regression analyses indicated that erythrocyte sedimentation rate was an independent predictor of a prolonged cTp-Te interval.Conclusions:Our study revealed that when compared with control subjects, Tp-Te and cTp-Te intervals and cTp-Te/QT ratio were increased in FMF patients.

Effect of propofol versus sevoflurane for corrected QT: a Meta-analysis

Objective Systematic review the effect of propofol versus sevoflurane for corrected QT(QTc). Methods The PubMed, Embase, Cochrane Library, CNKI and VIP databases were searched to obtain studies concerning the effect of sevoflurane versus propofol on cardiac cardiac electrophysiology. The quality of studies were assessed in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. After data extraction, Meta-analysis was performed with RevMan software 5.0. Results Three hundred and thirteen patients were involved in seven randomized-controlled trials (RCT) were used. The result of Meta-analysis shows that compared with myocardium repolarization time in propofol group, the duration of myocardium repolarize in sevoflurane group was prolonged obviously [(weighted mean difference, WMD)=-23.53, 95%CI(-30.57-16.49)](P 0.05). Conclusions Compared with propofol, sevoflurane prolong the duration of myocardium repolarization, increase the risk of arrhythmia, but the parameters of haemodynamics between two groups showed no significant differences. The result demonstrated that in the process of anesthesia induction, the effects of propofol on cardiac electrophysiology is less and safer than sevoflurane. Key words: Propofol; Sevoflurane; Corrected QT; Meta-analysis

Associations of Sex Hormones With Surface Electrocardiogram J Point Amplitude in Healthy Volunteers

Gender differences in J point height exist. Previous studies suggest male sex hormones mediate effects on cardiovascular disease through myocardial repolarization. Our objective was to assess whether male and female sex hormones are associated with J point amplitude in healthy subjects. We conducted a cross-sectional study of 475 healthy, mixed racial population of men, and premenopausal women (age 33 ± 9years, 56% male). Baseline J point amplitude (JPA) was obtained from continuous surface electrocardiograms. Plasma testosterone (T), dihydrotestosterone, estrone, 17-estradiol (E2), and sex hormone-binding globulin were measured. A free testosterone index (FTI) was calculated. Multivariate regression analysis stratified by gender and electrocardiographic lead location was used to determine independent predictors of maximum JPA. Regression analysis demonstrated FTI levels were positively associated with JPA in lateral leads (β=+0.01, p <0.05) in men but not in women. Total testosterone was positively associated with anterior electrocardiographic lead JPA in women (β=+0.5, p <0.02), but not in men. E2 was positively associated with inferior lead JPA (β=+1.2, p <0.03) in men but not in women. Total testosterone levels were positively associated with JPA in anterior leads (β=+0.054, p <0.05) in women. Male volunteers in the highest tertile of FTI demonstrated greater lateral JPA compared with the lowest tertile (p <0.05). Women in the highest tertile of FTI demonstrated greater anterior lead JPA compared with the lowest tertile (p <0.05). In conclusion, in a young, healthy population, the female sex hormone E2 and an FTI are independent determinants of JPA in men, whereas T is associated with JPA in women.

K+ and Mg2+ Dyshomeostasis in Acute Hyperadrenergic Stressor States

Acute stressor states are linked to neurohormonal activation that includes the adrenergic nervous system. Elevations in circulating epinephrine and norepinephrine unmask an interdependency that exists between K+ and Mg2+ based on their regulation of a large number of Mg2+-dependent Na+-K+-ATPase pumps present in skeletal muscle. The hyperadrenergic state accounts for a sudden translocation of cations into muscle with the rapid appearance of hypokalemia and hypomagnesemia. The resultant hypokalemia and hypomagnesemia will cause a delay in myocardial repolarization and electrocardiographic QTc prolongation raising the propensity for supraventricular and ventricular arrhythmias. In this review, we focus on the interdependency between K+ and Mg2+, which is clinically relevant to acute hyperadrenergic stressor states found in patients admitted to intensive care units.

Electrocardiographic RR and QT Interval Variability in Patients with Atrial Septal Defect and Healthy Children.

Atrial septal defect is a common congenital heart disease. In patients with atrial septal defect, left-to-right shunting increases the right atrial and right ventricular preload. This pathological change affects sinus node automaticity and myocardial depolarization and repolarization, and has the potential to evoke arrhythmogenic substrates. We examined the effect of atrial septal defect on sinus node automaticity and myocardial repolarization by investigating the variability in the repolarization interval, namely the QT variability index (QTVI) and variability ratio (VR). This retrospective study included 38 patients (mean age, 2.2 ± 1.9 years; mean left-to-right shunt ratio, 2.1 ± 0.70) and 40 age-matched healthy control subjects evaluated from 2008 to 2015. QTVI was calculated using the ratio of the repolarization parameter variance to heart rate variance, and VR was calculated as the ratio of the standard deviation (SD) of QT intervals to the SD of RR intervals on electrocardiography. There was a significant difference in the SD of all normal RR intervals, heart rate variance, VR, and QTVI of control subjects or patients with low shunt ratio compared with patients with high shunt ratio (all P < 0.05). Linear regression analysis revealed strong positive correlations between the left-to-right shunt ratio and VR (r = 0.662, P < 0.0001) or QTVI (r = 0.808, P < 0.0001). These repolarization indices provide information on alteration of sinus node autonomic control and the pathophysiology of myocardial repolarization, and could be used as a noninvasive indicator of the shunt ratio in children with atrial septal defect.

Colchicine Increases Ventricular Vulnerability in an Experimental Whole‐Heart Model

The traditional gout medication colchicine has been reported to effectively prevent atrial fibrillation recurrence after atrial fibrillation ablation or cardiac surgery in a few clinical trials. Severe adverse events have not yet been reported. The aim of the present study was to assess possible direct electrophysiological effects in an experimental whole-heart model. Ten rabbit hearts were isolated and Langendorff-perfused. Thereafter, colchicine was administered in two concentrations (1 and 3 μM). Eight endo- and epicardial monophasic action potentials and a 12-lead ECG showed a stable QT interval and action potential duration during colchicine infusion. Furthermore, there was no significant increase in dispersion of repolarization. However, colchicine induced a dose-dependent significant decrease of effective refractory period (ERP; 1 μM: -19 ms, 3 μM: -22 ms; p < 0.05). In the present study, acute infusion of colchicine in isolated rabbit hearts resulted in a reduction of ERP in the presence of a stable myocardial repolarization. This led to a significantly elevated inducibility of ventricular fibrillation. In 4 of 10 hearts, incessant ventricular fibrillation occurred. These results suggest a pro-arrhythmic or toxic effect of colchicine and underline that further clinical studies on potential adverse effects should be conducted before the drug can be recommended for routine use after atrial fibrillation ablation.

Cardiac Memory, an Underdiagnosed Condition

Introduction Cardiac memory, also termed Chatterjee phenomenon, is a known yet uncommonly recognized entity in which myocardial repolarization is altered after abnormal ventricular activation, such as with artificial pacemakers, intermittent left bundle branch block, ventricular premature beats, ventricular pre-excitation or episodes of tachycardia. This phenomenon is characterized by persistent but reversible T-wave changes on surface electrocardiogram (ECG) induced by an abnormal electrical activation pattern. The extent and direction of T-wave deviation depend on the duration and direction of abnormal electrical [...]

Evaluation of Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio in patients with mitral valve stenosis before and after balloon valvuloplasty.

Objective:Sympathetic activity increases in patients with mitral stenosis (MS). The association between prolonged Tpeak-Tend (Tp-e) interval and increased sympathetic activity has been demonstrated. This study aimed to evaluate Tp-e interval, Tp-e/QT ratio, and Tp-e/corrected QT interval (QTc) ratio in patients with MS before and after balloon valvuloplasty.Methods:Thirty patients with severe MS and 30 sex-, body mass index-, and and age-matched healthy control subjects were enrolled. The severity of MS was defined following clinical, transthoracic, and transesophageal echocardiographic examinations. All patients underwent successful mitral balloon valvuloplasty. Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were measured using 12-lead electrocardiogram. First, the abovementioned parameters were compared between patients with MS and healthy control subjects. Second, these parameters were compared before and after balloon valvuloplasty in patients with MS.Results:The mean Tp-e interval was significantly prolonged in patients with MS compared with healthy control subjects (85.02±9.12 ms vs. 75.38±6.04 ms; p<0.001). In addition, Tp-e/QT ratio and Tp-e/QTc ratio were significantly higher in patients with MS than in healthy control subjects (0.217±0.025 vs. 0.196±0.02 and 0.203±0.02 vs. 0.184±0.019; p<0.001).The mean valve area significantly increased after balloon valvuloplasty compared with that before balloon valvuloplasty (1.83±0.32 cm2 vs. 1.18±0.15 cm2; p<0.001). Compared with those before balloon valvuloplasty, Tp-e interval (85.02±9.12 ms vs. 78.06±9.2 ms; p<0.001), Tp-e/QT ratio (0.217±0.02 vs. 0.201±0.02; p<0.001), and Tp-e/QTc ratio (0.203±0.02 vs. 0.184±0.02; p<0.001) decreased after balloon valvuloplasty.Conclusion:We revealed that Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio increased in patients with severe MS. Furthermore, balloon valvuloplasty had a favorable effect on parameters associated with myocardial repolarization.