Fragmented QRS on Twelve-Lead Electrocardiogram Predicts Arrhythmic Events in Patients With Ischemic and Nonischemic Cardiomyopathy

Heart Rhythm. 2010 Jan;7(1):74-80. doi: 10.1016/j.hrthm.2009.09.065. Epub 2009 Oct 2.

Abstract

Background: Myocardial scar is a substrate for reentrant ventricular arrhythmias and is associated with poor prognosis. Fragmented QRS (fQRS) on 12-lead ECG represents myocardial conduction delays due to myocardial scar in patients with coronary artery disease (CAD).

Objective: The purpose of this study was to determine whether fQRS is associated with increased ventricular arrhythmic event and mortality in patients with CAD and nonischemic dilated cardiomyopathy (DCM).

Methods: Arrhythmic events and mortality were studied in 361 patients (91% male, age 63.3 +/- 11.4 years, mean follow-up 16.6 +/- 10.2 months) with CAD and DCM who received an implantable cardioverter-defibrillator for primary or secondary prophylaxis. fQRS included various RSR' patterns (QRS duration <120 ms), such as > or =1 R prime or notching of the R wave or S wave present on at least two contiguous leads of those representing anterior (V(1)-V(5)), lateral (I, aVL, V(6)), or inferior (II, III, aVF) myocardial segments.

Results: fQRS was present in 84 (23%) patients (fQRS group) and absent in 100 (28%) patients (non-fQRS group). Wide QRS (wQRS; QRS duration > or =120 ms) was present in 177 (49%) patients. Kaplan-Meier analysis revealed that event-free survival for an arrhythmic event (implantable cardioverter-defibrillator shock or antitachycardia pacing) was significantly lower in the fQRS group than in the non-fQRS and wQRS groups (P <.001 and P <.019, respectively). fQRS was an independent predictor of an arrhythmic event but not of death.

Conclusion: fQRS on 12-lead ECG is a predictor of arrhythmic events in patients with CAD and DCM. fQRS is associated with a significantly decreased time to first arrhythmic event compared with non-fQRS and wQRS.

MeSH terms

  • Aged
  • Arrhythmias, Cardiac / diagnosis*
  • Arrhythmias, Cardiac / mortality
  • Arrhythmias, Cardiac / therapy
  • Cardiomyopathy, Dilated / mortality*
  • Cardiomyopathy, Dilated / physiopathology
  • Cardiomyopathy, Dilated / therapy
  • Confidence Intervals
  • Coronary Artery Disease / mortality*
  • Coronary Artery Disease / physiopathology
  • Coronary Artery Disease / therapy
  • Defibrillators, Implantable*
  • Electrocardiography / instrumentation
  • Electrocardiography / methods*
  • Female
  • Heart Conduction System / physiopathology
  • Humans
  • Incidence
  • Indiana / epidemiology
  • Male
  • Middle Aged
  • Primary Prevention / instrumentation
  • Prognosis
  • Retrospective Studies
  • Risk Factors
  • Secondary Prevention / instrumentation