QRS fragmentation
Also calledfQRS · Fragmented QRS · Notched QRS
Definition
Extra notches or deflections within a QRS complex of normal duration (under 120 ms): an additional R wave (R'), more than one R', or notching of the R wave or of the nadir of the S wave, present in at least two contiguous leads of one coronary territory (anterior V1 to V5, inferior II, III and aVF, or lateral I, aVL and V6), without a typical bundle branch block. It reflects inhomogeneous ventricular activation caused by myocardial scar, and the more leads that show it, the worse the prognosis. When the QRS is wide (120 ms or more, as with bundle branch block, premature ventricular complexes or paced beats), similar notching is called fragmented wide QRS (f-wQRS), which is also a sign of scar and an independent predictor of mortality.
Clinical noteIn the original studies by Das and colleagues, fragmentation had to appear in two contiguous leads of one coronary territory, and typical bundle branch block and incomplete right bundle branch block were excluded. A notch in the S wave in V1 and V2 can instead reflect a terminal conduction delay, so fQRS is a nonspecific finding.
Sources
- Das MK, Khan B, Jacob S, Kumar A, Mahenthiran J. Significance of a fragmented QRS complex versus a Q wave in patients with coronary artery disease. Circulation. 2006;113(21):2495-2501. doi.org/10.1161/CIRCULATIONAHA.105.595892
- Das MK, Suradi H, Maskoun W, et al. Fragmented wide QRS on a 12-lead ECG: a sign of myocardial scar and poor prognosis. Circ Arrhythm Electrophysiol. 2008;1(4):258-268. doi.org/10.1161/CIRCEP.107.763284
- Samesima N, God EG, Kruse JCL, et al. Brazilian Society of Cardiology guidelines on the analysis and issuance of electrocardiographic reports - 2022. Arq Bras Cardiol. 2022;119(4):638-680. doi.org/10.36660/abc.20220623
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.