Abstract 20836: Prevalence of Fragmented QRS Complexes in Non-Ischemic Dilated Cardiomyopathy Patients and Long Term Prognosis
Objectives: Fragmented QRS complexes (fQRS), which include various RSR' patterns without a typical bundle-branch block pattern, are thought to represent myocardial scarring. Presence of fQRS is associated with increased mortality in patients with ischemic cardiomyopathy. The prognostic significance of fQRS in patients with nonischemic dilated cardiomyopathy remain unknown.
Methods: All eligible patients diagnosed with nonischemic dilated cardiomyopathy between January 2000 and December 2005 were included in this retrospective study. Patients requiring pacing or with bundle branch block pattern were excluded. All ECGs were manually checked for fQRS by two independent reviewers. The total number of leads with fQRS, left ventricular ejection fraction (LVEF), and long-term outcomes with all-cause mortality were analyzed. Mortality data were obtained from the Social Security Death Index database in October 2009.
Results: Inclusion criteria were met by 458 patients (age 67±14 years, 65% male, 75% Caucasians, BMI 28.8± 6.8 kg/sq m) with a mean EF of 25±7.3% at the time of diagnosis. The average QRS duration on the ECG was 95±11mSec. On average, 18% of ECG leads showed fragmentation. A total of 119 (26%) patients received defibrillators (91 [20%] received ICDs and 28 [6%] received CRT-Ds) during the follow-up period. Overall mortality was 29% (n=134) during the 5-year follow-up period. The total number leads showing fQRS in an ECG correlated inversely and significantly with LVEF, but not with mortality. Pearson correlation coefficient for LVEF and the number of fQRS leads was r(457) = -0.1, p<0.05; and for mortality was r(457)=0.045, p=0.34.
Conclusions: In patients with nonischemic dilated cardiomyopathy, the number of ECG leads with fQRS correlates inversely with LVEF but not with mortality. These results identify important differences in prognostic implications of fQRS in patients with nonischemic versus ischemic cardiomyopathy.
- © 2010 by American Heart Association, Inc.