Assessment of Ventricular Repolarization in Sickle Cell Anemia Patients: The Role of QTc Interval, Tp-e Interval and
Adeola Olubunmi Ajibare1, Olatunde Peter Olabode2, Emmanuel Yemi Fagbemiro3
1Department of Medicine, Lagos State University College of Medicine Ikeja, Lagos, Nigeria.
Insights
Sickle cell anemia (SCA) patients show altered ventricular repolarization, with prolonged QTc intervals. Male SCA patients have increased risk of arrhythmias, while BMI and PAI-1 may indicate repolarization issues.
Area of Science:
- Cardiology
- Hematology
- Electrophysiology
Background:
- Sickle cell anemia (SCA) is associated with electrocardiographic abnormalities and increased risk of ventricular arrhythmias.
- Ventricular repolarization abnormalities, assessed by corrected QT (QTc) interval, Tp-e interval, and Tp-e/QTc ratio, are crucial indicators of arrhythmogenesis risk in SCA.
Purpose of the Study:
- To evaluate ventricular repolarization abnormalities in SCA patients using QTc, Tp-e, and Tp-e/QTc.
- To investigate gender differences in these repolarization parameters.
- To identify determinants of ventricular repolarization abnormalities in SCA.
Main Methods:
- Sixty SCA patients and 60 healthy controls underwent ECG, physical examination, and hematological/biochemical evaluation.
- QT and Tp-e intervals were measured from ECGs; QTc was calculated using Bazett's formula.
- Derived Tp-e/QT and Tp-e/QTc ratios for comprehensive repolarization assessment.
Main Results:
- SCA subjects exhibited prolonged QT and QTc intervals.
- Male SCA subjects showed prolonged Tp-e interval and Tp-e/QTc ratio, while females showed paradoxical shortening.
- Plasminogen activator inhibitor-1 (PAI-1) and body mass index (BMI) were identified as independent determinants of repolarization parameters.
Conclusions:
- Male SCA subjects demonstrate an elevated risk for ventricular arrhythmogenesis.
- Increased BMI and PAI-1 levels may serve as potential markers for ventricular repolarization abnormalities in SCA patients.
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.
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