Ayşe GÜLER EROĞLU, Ebru İMAMOĞLU YALIN

Primer mitral kapak prolapsusu olan çocuklarda QT dispersiyonu ve ventriküler aritmiler

Amaç: Primer mitral kapak prolapsusu olan çocuklardaki ventriküler aritmileri araştırmak ve ventriküler aritmilerin QT uzunluğu, QT dispersiyonu, otonom işlev testleri ve kalp hızı değişkenliği ile ilişkisini değerlendirmektir.Gereç ve Yöntemler: Primer mitral kapak prolapsusu olan 42 çocuk hasta ve 32 sağlıklı çocuk çalışmaya alındı. Oniki derivasyonlu elektrokardiyogram, 24 saatlik ritim Holter'i, otonom işlev testleri ve ekokardiyografi yapıldı. Elektrokardiyogramlar dijital ortamda büyütüldü. QT uzunluğu kalp hızına göre düzeltildi. Hastalar 24 saatlik ritm Holter'indeki ventriküler erken vuru sayısına ve kompleks ventriküler aritmi varlığına göre gruplandırıldı. Kalp hızı değişkenliği ölçümleri 24 saatlik ritim Holter'inden otomatik olarak hesaplandı. Otonom işlev testlerinden ortostatik hipotansiyon ve dinlenme kalp hızı kullanıldı. Bulgular: Hastaların yaş ortalaması 13,9±3,3 yıl ve kontrol grubunun yaş ortalaması 14,6±3,1 yıl idi (p>0,05). Hastaların 34'ü kız (%81), sekizi erkek (%19) ve kontrol grubunun 25'i kız (%78), yedisi erkekti (%22) (p>0,05). Hastaların QT dispersiyonu ve düzeltilmiş QT mesafesi kontrol grubuna kıyasla anlamlı derecede artmış olarak bulundu (56±16 ms ve 43±11 ms, p=0,001; 426±25 ms ve 407±26 ms, p=0,002). Yirmi dört saatlik ritim Holter incelemesinde 42 hastanın 21'inde (%50) ve 32 sağlıklı kontrolün altısında (%19) ventriküler erken atım saptandı (p=0,006). Yirmi dört saatte 10'un üzerinde ventriküler erken atımları olan ve/veya kompleks ventriküler aritmileri olan hastalarda QT dispersiyonunun ventriküler erken atımları olmayan sağlıklı çocuklara göre anlamlı derecede yüksek olduğu saptandı (p=0,002). Hasta ve kontrol grubu arasında kalp hızı değişkenliği ölçümleri ve otonom işlev testleri açısından anlamlı farklılık saptanmadı.Çıkarımlar: Primer mitral kapak prolapsusu olan çocuklarda QT dispersiyonu ventriküler aritmilerin değerlendirilmesinde faydalı bir gösterge olabilir

QT dispersion and ventricular arrhythmias in children with primary mitral valve prolapse

Aim: To investigate ventricular arrhythmias in children with primary mitral valve prolapse and to evaluate its relation with QT length, QT dispersion, autonomic function tests and heart rate variability measurements.Material and Methods: Fourty two children with mitral valve prolapse and 32 healthy children were enrolled into the study. Twelve-lead electrocardiograms, autonomic function tests, echocardiography and 24-hour rhythm Holter tests were performed. Electrocardiograms were magnified digitally. The QT length was corrected according to heart rate. The patients were grouped according to the number of premature ventricular contractions and presence of complex ventricular arhythmia in the 24-hour rhythm Holter monitor test. Heart rate variability measurements were calculated automatically from the 24-hour rhythm Holter monitor test. Orthostatic hypotension and resting heart rate were used as autonomic function tests. Results: The mean age was 13.9±3.3 years in the patient group and 14.6±3.1 years in the control group (p>0.05). Thirty four of the patients (81%) were female and eight (19%) were male. Twenty five of the control subjects (78%) were female and seven (22%) were male. The QT dispersion and heart rate corrected QT interval were found to be significantly increased in the children with primary mitral valve prolapse when compared with the control group (56±16 ms vs. 43±11 ms, p=0.001; 426±25 ms vs. 407±26 ms, p=0.002, respectively). In 24hour rhythm Holter monitor tests, ventricular arrhythmias were found in 21 out of 42 patients (50%) and 6 out of 32 control subjects (18.8%) (p=0.006). QT dispersion was found to be significantly increased in patients with premature ventricular contractions >= 10/day and/or complex ventricular arrhythmias compared to the control group without ventricular premature beats (p=0.002). There was no significant difference in autonomic function tests and heart rate variability measurements between the patient and control groups.Conclusions: The noted increase in QT dispersion may be a useful indicator for the clinician in the evaluation of impending ventricular arrhythmias in children with primary mitral valve prolapse

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