Prognostic significance of fragmented QRS complex for predicting the risk of recurrent cardiac events in patients with Q-wave myocardial infarction.
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.
Pietrasik
Grzegorz
G
Heart Research Follow-up Program, Cardiology Division, Department of Medicine, University of Rochester Medical Center, Rochester, New York, USA.
Goldenberg
Ilan
I
Zdzienicka
Joanna
J
Moss
Arthur J
AJ
Zareba
Wojciech
W
D002170:Canada; D016001:Confidence Intervals; D018450:Disease Progression; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007557:Israel; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology*; D011379:Prognosis; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D014481:United States