Transmurálna disperzia komorovej repolarizácie a jej vzťah k výskytu malígnych komorových arytmií u pacientov po infarkte myokardu / Transmural dispersion of ventricular repolarization and its relation to incidence of malignant ventricular arrhythmias in

Increased repolarization heterogeneity can provide the substrate for reentrant ventricular arrhythmias in animal models of cardiomyopathy. We hypothesized that ventricular repolarization heterogeneity is also greater in patients with cardiomyopathy and ventricular arrhythmia vulnerability (inducible ventricular tachycardia or positive microvolt T wave alternans, VT/TWA) compared with a similar patient population without ventricular arrhythmia vulnerability (no VT/TWA). Endocardial and epicardial repolarization heterogeneity was measured in patients with ( n = 12) and without ( n = 10) VT/TWA by using transvenous 26-electrode catheters placed along the anteroseptal right ventricular endocardium and left ventricular epicardium. Local activation times (AT), activation-recovery intervals (ARI), and repolarization times (RT) were measured from unipolar electrograms. Endocardial RT dispersion along the apicobasal ventricle was greater ( P < 0.005) in patients with VT/TWA than in those without VT/TWA because of greater ARI dispersion ( P < 0.005). AT dispersion was similar between the two groups. Epicardial RT dispersion along the apicobasal ventricle was greater ( P < 0.05) in patients with VT/TWA than in those without VT/TWA because of greater ARI dispersion ( P < 0.05). AT dispersion was similar between the two groups. A plot of AT as a function of ARI revealed an inverse linear relationship for no VT/TWA such that progressively later activation was associated with progressively shorter ARI. The AT-ARI relationship was nonlinear in VT/TWA. In conclusion, patients with cardiomyopathy and VT/TWA have greater endocardial and epicardial repolarization heterogeneity than those without VT/TWA without associated conduction slowing. The steep repolarization gradients in VT/TWA may provide the substrate for functional conduction block and reentrant ventricular arrhythmias.

Download Full-text

Evaluation of Ventricular Repolarization Parameters in Patients Admitted to Emergency Department with Electrical Injury

10.22514/sv.2020.16.0076 ◽

2020 ◽

Keyword(s):

Ventricular Arrhythmias ◽

Troponin I ◽

Ventricular Repolarization ◽

Control Group ◽

Qtc Interval ◽

Elevated Troponin ◽

Surface Ecg ◽

Healthy Control ◽

The Mean ◽

Electrocardiogram Ecg

Objective: Prolonged T-peak to T-end (Tp-e), a ventricular repolarization parameter, has been related with ventricular arrhythmias (VAs). Novel electrocardiogram (ECG) parameters of ventricular repolarization have received considerable attention recently. In this study, we sought to investigate ventricular repolarization indexes such as the Tp-e and corrected Tp-e (Tp-ec) intervals, Tp-e/QT, Tp-e/QTc, and Tp-ec/QT ratios in patients with electrical injuries (EIs). Methods: Thirty-six patients diagnosed with EIs and 35 age- and sex-matched healthy control patients were included. Admission ECGs of the EI patients were compared with those of the healthy controls. QT and QTc intervals were measured, and the Tp-e and Tp-ec intervals, Tp-e/QT, Tp-ec/QT, and Tp-e/QTc ratios were then calculated from a 12-lead surface ECG. Results: The QT, Tp-e, Tp-e/QT, Tp-e/QTc, Tp-ec/QT were not significantly different between the control group and the EI group (p > 0.05). However, the mean QTc interval was significantly higher in the EI group compared to the control group (412.81 ± 25.46 vs 396.31 ± 26.47 ms; p:0.009). Furthermore, the Tp-ec and Tp-ec/QT of the EI subgroup with elevated troponin levels significantly differed from those of the EI patients with normal troponin levels (p:0.033 and p:0.016, respectively). Conclusions: This retrospective study indicated that patients with EIs tend to have a prolonged QTc interval. Additionally, Tp-ec and Tp-ec/QT, which reportedly designate the tendency for VAs, were significantly higher in the EI patients with elevated troponin I levels than the EI patients with normal troponin levels, suggesting that patients with myocardial injury may be prone to VAs.

Download Full-text

Relationship between ventricular repolarization parameters and the inducibility of ventricular arrhythmias during electrophysiological study in patients with coronary artery disease

10.22541/au.160406471.14660475/v1 ◽

2020 ◽

Author(s):

Guilherme de Carvalho ◽

Dalmo Moreira ◽

Renato Lopes ◽

Márcia Olandoski ◽

Beatriz Galvão ◽

...

Keyword(s):

Coronary Artery Disease ◽

Coronary Artery ◽

Ventricular Arrhythmias ◽

Electrophysiological Study ◽

Ventricular Repolarization ◽

Artery Disease

Download Full-text

Assessment of Transmural Dispersion of Repolarization in Children with Mitral Valve Prolapse

The Journal of Tehran University Heart Center ◽

10.18502/jthc.v15i2.4185 ◽

2020 ◽

Author(s):

Yazdan Ghandi ◽

Bita Ghahremani ◽

Danial Habibi ◽

Afsane Pouya ◽

Saiid Sadrnia

Keyword(s):

Mitral Valve ◽

Mitral Regurgitation ◽

Mitral Valve Prolapse ◽

Ventricular Arrhythmias ◽

Healthy Children ◽

Qtc Dispersion ◽

Dispersion Of Repolarization ◽

Transmural Dispersion Of Repolarization ◽

Positive Correlations ◽

Transmural Dispersion

Background: Children with mitral valve prolapse (MVP) may be prone to ventricular arrhythmias due to transmural dispersion of repolarization (TDR). This study aimed to assess alterations in ventricular repolarization in children with MVP and to investigate their relationships with the degree of mitral regurgitation. Methods: Fifty children with MVP and 50 age- and sex-matched healthy children as controls were studied. Twelve-lead electrocardiography and echocardiography were performed in all the subjects. TDR parameters were QT and QTc intervals, QTc dispersion, Tp-e interval, Tp-e interval dispersion, Tp-e/QT, Tp-e/QTc, JTc, JTc dispersion, Tp-e/JT, and Tp-e/JTc. Results: The mean age of the 50 patients with MVP was 12.45±2.50 years (F/M: 15/35). There were no significant differences in QT and QTc intervals between the 2 groups. QTc dispersion (P=0.001), Tp-e dispersion interval (P=0.002), Tp-e/QTc (P=0.001), JTc dispersion (P=0.023), Tp-e/JT (P=0.004), and Tp-e/JTc (P=0.002) were significantly higher in the patients with MVP than in the healthy controls. Positive correlations were found between Tp-e dispersion interval and Tp-e/QTc and an increase in the degree of mitral regurgitation (P=0.012, r=0.42 and P=0.004, r=0.31, respectively). Additionally, positive correlations were detected between JTc dispersion and Tp-e/JTc and an increase in the degree of mitral regurgitation (P=0.032, r=0.20 and P=0.024, r=0.42, correspondingly). Conclusion: In this study, TDR was damaged in children with MVP and was positively correlated with an increase in the degree of mitral regurgitation. It appears that children with MVP are prone to life-threatening ventricular arrhythmias.

Download Full-text