Prognostic significance of fragmented QRS complex for predicting the risk of recurrent cardiac events in patients with Q-wave myocardial infarction

Am J Cardiol. 2007 Aug 15;100(4):583-6. doi: 10.1016/j.amjcard.2007.03.063. Epub 2007 Jun 29.


There are limited data regarding the prognostic value of QRS complex fragmentation, defined as changes in QRS morphology (<120 ms) with different RSR' patterns: additional R waves, notched S wave, or >1 R' wave. The purpose of our analysis was to assess the prognostic value of presence of Q waves and QRS fragmentation for predicting recurrent cardiac events, defined as cardiac death, nonfatal myocardial infarction (MI), or unstable angina, whichever occurs first, in 350 patients with first Q-wave MI. In follow-up (2 months on average) electrocardiograms (ECGs), 277 patients (79%) had persistent Q waves and 73 (21%) had resolution of Q waves. Independently of Q waves, presence of QRS complex fragmentation was found in 187 patients (53%). Resolved Q waves on 2-month ECGs was associated with worsened prognosis (adjusted hazard ratio [HR] 2.33, p = 0.007), whereas presence of any fragmented QRS did not increase risk of recurrent cardiac events (adjusted HR 0.93, p = 0.79). Among patients for whom Q waves disappeared on 2-month ECGs, patients with QRS fragmentation (n = 37) had over twofold higher risk of recurrent events (adjusted HR 2.68, p = 0.004) compared with those without fragmented QRS and persistent Q waves. In conclusion, presence of fragmented QRS independently of Q waves was not associated with increased risk of recurrent events in the general population of patients after MI. However, among patients with resolved Q waves, fragmented QRS was associated with increased risk of cardiac events. Fragmented QRS complex should not be neglected in patients with transient Q waves after myocardial infarction.

Publication types

  • Multicenter Study

MeSH terms

  • Canada
  • Confidence Intervals
  • Disease Progression
  • Electrocardiography*
  • Female
  • Follow-Up Studies
  • Humans
  • Israel
  • Male
  • Middle Aged
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / physiopathology*
  • Prognosis
  • Recurrence
  • Retrospective Studies
  • Risk Factors
  • Severity of Illness Index
  • Time Factors
  • United States