FRONTAL QRS-T ANGLE AS A MARKER OF LEFT VENTRICULAR HYPERTROPHY IN PATIENTS WITH ESSENTIAL HYPERTENSION

Öz

Objective: Previous studies showed that myocardial repolarization markers are prolonged in hypertensive patients with left ventricular hypertrophy (LVH) compared to patients with non-LVH. Frontal QRS-T angle, angle between the QRS and T wave axes, is novel marker of myocardial repolarization. The aim of our study is to investigate the relationship between frontal QRS-T angle and LVH in hypertensive patients.

Material and Method: A total 187 hypertensive patients were included our study. Frontal QRS-T angle was obtained from the automatic reports of the ECG machine. LVH was defined as left ventricular mass index (LVMI) > 115 g/m2 in men and 95 g/m2 in women. Results: Patients with LVH had significantly longer QT dispersion (p=0.028), corrected QT dispersion (p=0.010), Tp-e interval (p = 0.045) and wider frontal QRS-T angle (p<0.001) compared to patients with non-LVH. In correlation analysis, LVMI was positively correlated with QT dispersion (r=0.150, p=0.041), corrected QT dispersion (r=0.167, p=0.022), Tp-e interval (r = 0.160, p = 0.046) and frontal QRS-T angle (r=0.360, p<0.001). By a multivariate analysis, frontal QRS-T (OR: 1.04, 95% CI: 1.02-1.06, P < 0.001) angle was found to be the only independent predictor of LVH. ROC curve analysis showed that the best cut-off value of frontal QRS-T angle for predicting LVH was ≥ 28o. This cut-off value predicted LVH with a sensitivity of 70.5% and a specificity of 54.5%. Conclusion: Frontal QRS-T angle is a simple, inexpensive and easily obtainable parameter from surface electrocardiography. It can be used as a simple marker of LVH in hypertensive subjects.

Anahtar Kelimeler

• hypertension,left ventricular hypertrophy,electrocardiography,frontal QRS-T angle

Esansiyel Hipertansiyonlu Hastalarda Sol Ventrikül Hipertrofisinin Bir Göstergesi Olarak Frontal QRS-T Açısı

Öz

Amaç: Önceki çalışmalarda sol ventrikül hipertrofisi (SVH) bulunan hipertansif hastalarda, SVH bulunmayan hastalara göre miyokardiyal repolarizasyon belirteçlerinin uzamış olduğu gösterilmiştir. Ortalama QRS ve T dalgası eksenleri arasındaki açı olarak tanımlanan frontal QRS-T açısı da miyokard repolarizasyonunun yeni bir göstergesidir. Çalışmamızın amacı, hipertansif hastalarda frontal QRS-T açısı ile SVH arasındaki ilişkiyi incelemektir.

Gereç ve Yöntem: Çalışmamıza toplam 187 hipertansif hasta dâhil edildi. Frontal QRS-T açısı, EKG cihazının otomatik raporlarından elde edildi. Sol ventrikül kitle indeksinin (SVKİ) erkeklerde > 115 g/m², kadınlarda > 95 g/m² olması SVH olarak tanımlandı.

Bulgular: SVH bulunan hastalarda, SVH bulunmayan hastalara göre QT dispersiyonu (p = 0,028), düzeltilmiş QT dispersiyonu  (p = 0,010) ve Tp-e aralığı (p = 0,045) daha uzun, frontal QRS-T açısı (p < 0,001) ise daha genişti. Korelasyon analizinde, SVKİ QT dispersiyonu (r= 0,150, p= 0,041), düzeltilmiş QT dispersiyonu (r= 0,167, p= 0,022), Tp-e aralığı (r= 0,160, p= 0,046)  ve frontal QRS-T açısı (r= 0,360, p < 0,001) ile pozitif bir şekilde korele idi. Çok değişkenli analizle, frontal QRS-T açısı SVH'nin tek bağımsız prediktörü olarak bulundu (OR: 1,04, 95% CI: 1,02-1,06, p < 0,001). ROC curve analizinde frontal QRS-T açısının SVH'yi göstermedeki en iyi kesme değeri 28^o idi. Bu kesme değer, SVH'yi %70,5 sensitivite ve %54,5 spesifite ile öngördü.

Sonuç: Frontal QRS-T açısı, basit, ucuz ve 12 derivasyonlu yüzey elektrokardiyografiden kolaylıkla elde edilebilen bir parametredir. Bu açı, hipertansif hastalarda SVH'nin basit bir göstergesi olarak kullanılabilir.

Anahtar Kelimeler

• Hipertansiyon,sol ventrikül hipertrofisi,elektrokardiyografi,frontal QRS-T açısı

Kaynakça

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