Effects of Lithium Therapy on Ventricular Repolarization in Bipolar Disorder Patients

Abstract

Introduction: Bipolar disorder (BD) is a significant mental health concern in the world. Most of the drugs used in the treatment of bipolar disease may cause life-threatening arrhythmias by affecting the distribution of ventricular repolarization (VR). VR is commonly assessed using QT interval and Twave measurements. The aim of this study was to evaluate VR using the T peak to T end (Tp-e) interval and the Tp-e/QT ratio and to investigate the relationship between lithium therapy and VR parameters in patients with BD.

Patients and Methods: Forty-six BD patients under lithium therapy and 45 participants in a control group were included in our study. The Tp-e interval and Tp-e/QT ratio were measured using 12derivation electrocardiography (ECG). These parameters were compared between groups.

Results: The QT interval (p= 0.01), QTc interval (p= 0.003), Tp-e interval (p< 0.001), and Tpe/QT ratio (p= 0.009) were significantly higher in patients with BD than in the control group. There was a positive correlation between the Tp-e interval and serum lithium levels (r= 0.317, p< 0.032). In addition, the increased serum lithium level (β= 0.398, p= 0.007) was found to be an independent predictor of the prolonged Tp-e interval.

Conclusion: Prolonged Tp-e interval may be a useful indicator of increased risk of ventricular arrhythmia in patients using lithium therapy.

Keywords

• Bipolar disorder,lithium,Tp-e interval,ventricular repolarization

Bipolar Bozukluk Hastalarında Lityum Tedavisinin Ventriküler Repolarizasyon Üzerine Etkileri

Abstract

Giriş: Bipolar bozukluk (BD) dünyada önemli bir mental sağlık sorununudur. Bipolar bozukluk tedavisinde kullanılan ilaçların çoğu, ventriküler repolarizasyonun (VR) dağılımını etkileyerek hayatı tehdit eden aritmilere neden olabilir. VR genellikle QT aralığı ve T dalgası ölçümleri kullanılarak değerlendirilir. Bu çalışmanın amacı, Tp-e intervali ve Tp-e/QT oranını kullanarak VR’yi değerlendirmek ve bipolar bozukluğu olan hastalarda lityum tedavisi ve VR parametreleri arasındaki ilişkiyi araştırmaktır.

Hastalar ve Yöntem: Çalışmamıza lityum tedavisi alan 46 hasta ve 45 katılımcıdan oluşan kontrol grubu dahil edildi. Tp-e aralığı ve Tp-e/QT oranı 12-derivasyon elektrokardiyografi (EKG) kullanılarak ölçüldü. Bu parametreler gruplar arasında karşılaştırıldı.

Bulgular: Bipolar bozukluk olan hastalarda QT interval (p= 0.01), QTc interval (p = 0.003), Tp-e interval (p< 0.001) ve Tp-e / QT oranı (p= 0.009) kontrol grubuna göre anlamlı olarak yüksek bulundu. Tp-e intervali ile serum lityum düzeyleri arasında pozitif korelasyon vardı (r= 0.317, p< 0.032). Ayrıca artmış serum lityum seviyesi (β= 0.398, p= 0.007), uzun Tp-e aralığının bağımsız bir belirleyicisi olarak bulundu.

Sonuç: Uzamış Tp-e intervali, lityum tedavisi kullanan hastalarda artmış ventriküler aritmi riskinin yararlı bir göstergesi olabilir.

Keywords

• Bipolar bozukluk,lityum,Tp-e interval,ventriküler repolarizasyon

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