Fragmented QRS: Electrophysiological Bases, Pathophysiological Mechanisms, and Clinical Prognostic Significance

Öz

Background: Fragmented QRS (fQRS) is characterized by morphological irregularities in ventricular depolarization on a standard 12-lead surface electrocardiogram (ECG) and is considered a non-invasive indicator of myocardial conduction heterogeneity. Microstructural changes such as non-uniform anisotropy, gap junction reorganization, and interstitial fibrosis can disrupt the propagation of the electrical impulse, leading to notching in the QRS complex. Methods: This study is designed as a narrative review to evaluate the electrophysiological basis and clinical implications of fQRS. A literature search was conducted in the PubMed, Scopus, and Web of Science databases to include peer-reviewed articles published between 2006 and 2025 that addressed fQRS, myocardial scarring, and ventricular arrhythmias (VA). Results: Current data indicate that the presence of a fQRS shows a strong correlation with myocardial scarring, particularly in ischemic cardiomyopathies, and may serve as an independent risk marker for VA and cardiac mortality. Additionally, it has been reported that in heart failure (HF) and certain channelopathies, fQRS carries prognostic value as a superficial reflection of electrical remodeling. However, the fact that evaluation methods are largely visual and qualitative, along with interobserver variability and dependence on ECG filter settings, limits the clinical utility of this finding. Conclusion: Fragmented QRS has the potential to provide important prognostic information as an electrocardiographic indicator of myocardial fibrosis and conduction heterogeneity. However, standardized definition criteria, quantitative analysis methods, and large-scale prospective studies are required for its integration into routine clinical practice.

Anahtar Kelimeler

• Arrhythmias
• electrical remodeling
• electrocardiography
• fragmented QRS.

Fragmante QRS: Elektrofizyolojik Temeller, Patofizyolojik Mekanizmalar ve Klinik Prognostik Önemi

Öz

Gerekçe: Fragmante QRS, standart 12 derivasyonlu yüzey elektrokardiyogramında ventriküler depolarizasyonun morfolojik düzensizlikleri ile karakterize olup, miyokardiyal ileti heterojenitesinin non-invaziv bir göstergesi olarak kabul edilmektedir. Non-üniform anizotropi, gap junction yeniden düzenlenmesi ve interstisyel fibrozis gibi mikroyapısal değişiklikler, elektriksel uyarının yayılımını bozarak QRS kompleksinde çentiklenmelere yol açabilmektedir. Yöntemler: Bu çalışma, fragmante QRS’in elektrofizyolojik temellerini ve klinik yansımalarını değerlendirmeye yönelik anlatısal bir derleme olarak tasarlanmıştır. Literatür taraması, PubMed, Scopus ve Web of Science veri tabanlarında 2006–2025 yılları arasında yayımlanan, fragmante QRS, miyokardiyal skar ve ventriküler aritmiler ile ilişkili hakemli makaleleri kapsayacak şekilde gerçekleştirilmiştir. Bulgular: Mevcut veriler, fragmante QRS varlığının özellikle iskemik kardiyomiyopatilerde miyokardiyal skar ile güçlü korelasyon gösterdiğini ve ventriküler aritmi ile kardiyak mortalite açısından bağımsız bir risk belirteci olabileceğini ortaya koymaktadır. Ayrıca kalp yetersizliği ve bazı kanalopatilerde, fragmante QRS’in elektriksel yeniden şekillenmenin yüzeysel bir yansıması olarak prognostik değer taşıdığı bildirilmiştir. Bununla birlikte, değerlendirme yöntemlerinin büyük ölçüde görsel ve kalitatif olması, gözlemciler arası değişkenlik ve elektrokardiyogram filtre ayarlarına bağımlılık, bulgunun klinik kullanımını sınırlamaktadır. Sonuç: Fragmante QRS, miyokardiyal fibrozis ve ileti heterojenitesinin elektrokardiyografik bir göstergesi olarak önemli prognostik bilgiler sunma potansiyeline sahiptir. Ancak rutin klinik pratiğe entegrasyonu için standardize tanım kriterleri, kantitatif analiz yöntemleri ve geniş ölçekli prospektif çalışmalar gereklidir.

Anahtar Kelimeler

• Aritmiler
• elektriksel yeniden şekillenme
• elektrokardiyografi
• fragmante QRS.

Kaynakça

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