Evaluation of Tp-e interval and Tp-e/QT ratio in patients with ankylosing spondylitis

Assessment of Ventricular Repolarization in Sickle Cell Anemia Patients: The Role of QTc Interval, Tp-e Interval and Tp-e/QTc Ratio and Its Gender Implication

Background

Many specific and non-specific electrocardiographic abnormalities including ventricular arrhythmias have been reported in subjects with sickle cell anemia (SCA). In SCA patients, cardiac electrical abnormalities may be the leading cause of increased risk of arrhythmias. The corrected QT (QTc) interval, peak to the end of the T wave (Tp-e) interval and associated Tp-e/QTc ratio are promising measures of altered ventricular repolarization and increased arrhythmogenesis risk.

Aim

This study assessed ventricular repolarization abnormalities in subjects with SCA using the QTc interval, Tp-e interval and Tp-e/QTc ratio, and also evaluated the gender differences in these parameters, as well as their determinants.

Methods

Sixty subjects with SCA and 60 healthy control subjects, matched for age and gender, were studied. All participants underwent physical examination, hematological and biochemical evaluation, and 12-lead electrocardiography (ECG) recording. QT and Tp-e intervals were measured from the ECG, and the QTc interval was calculated using Bazett’s formula. Tp-e/QT and Tp-e/QTc ratios were also derived.

Results

QT and QTc intervals were prolonged in subjects with SCA. Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio were prolonged in male SCA subjects, with a paradoxical shortening in female SCA subjects. Plasminogen activator inhibitor-1 (PAI-1) was an independent determinant of QTc, while body mass index (BMI) was an independent determinant of both Tp-e interval and Tp-e/QTc ratio.

Conclusion

Our results suggest an elevated risk for ventricular arrhythmogenesis in male SCA subjects. Furthermore, increased BMI and PAI-1 level are possible markers of ventricular repolarization abnormalities in SCA subjects.

Evaluation of Tp-Te Interval and Tp-Te/QT Ratio in Patients with Coronary Slow Flow Tp-Te/QT Ratio and Coronary Slow Flow

OBJECTIVE

Coronary slow flow (CSF) phenomenon is described by angiographically normal coronary arteries with delayed opacification of the distal vasculature. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-Te) may correspond to the transmural dispersion of the repolarization and that increased Tp-Te interval and Tp-Te/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate the ventricular repolarization by using Tp-Te interval and Tp-Te/QT ratio in patients with CSF.

MATERIALS AND METHODS

This study included 50 CSF patients (40 male, mean age 48.6±12.5 years) and 40 control individuals (23 male, mean age 47.8±12.5 years). Tp-Te interval and Tp-Te/QT ratio were measured from the 12-lead electrocardiogram. These parameters were compared in groups.

RESULTS

Baseline characteristics of the study groups were comparable. In electrocardiographic parameters analysis, QT and corrected QT were similar in CSF patients compared to the controls (357±35.2 vs 362±38.0 milliseconds and 419±25.8 vs 430±44.2 milliseconds, all p value >0.05). Tp-Te interval, Tp-Te/QT and Tp-Te/QTc ratio were significantly higher in CSF patients (85±13.7 vs 74±9.9 milliseconds and 0.24±0.03 vs 0.20±0.02 and 0.20±0.03 vs 0.17±0.02 all p value <0.001).

CONCLUSION

Our study revealed that QTd, Tp-Te interval and Tp-Te/QT ratio are prolonged in patients with CSF.

Evaluation of Tpe interval and Tpe/QT ratio in patients with slow coronary flow

OBJECTIVE

Slow coronary flow (SCF) phenomenon is described as the delayed opacification of the distal vasculature and angiographically normal coronary arteries. Considerable studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tpe) may correspond to the transmural dispersion of repolarization and that increased Tpe interval and Tpe/QT ratio are associated with malignant ventricular arrhythmias. In this study, we intended to evaluate ventricular repolarization in patients with SCF by using the Tpe interval and Tpe/QT ratio.

METHODS

The study population included 33 patients with angiographically proven SCF and 33 control patients with angiographically proven normal coronary arteries without associated SCF. Coronary flow rates of patients and the control group were documented by TIMI (Thrombolysis in Myocardial Infarction) frame count. From the electrocardiograms, Tpe interval and Tpe/QT ratio were calculated and compared between groups.

RESULTS

No statistically significant difference was found between the two groups in terms of basic characteristics. Mean Tpe interval, Tpe/QT ratio, and Tpe/QTc ratio were prolonged in the study group compared to the control group (p<0.001).

CONCLUSION

Tpe interval and Tpe/QT ratio were increased in SCF patients.