Elsevier

Heart Rhythm

Volume 4, Issue 11, November 2007, Pages 1385-1392
Heart Rhythm

Original-clinical
Fragmented QRS on a 12-lead ECG: A predictor of mortality and cardiac events in patients with coronary artery disease

https://doi.org/10.1016/j.hrthm.2007.06.024Get rights and content

Background

Fragmented QRS (fQRS) on a 12-lead electrocardiogram (ECG) is associated with myocardial scar in patients with coronary artery disease (CAD).

Objective

We postulated that fQRS is a predictor of cardiac events and mortality in patients who have known CAD or who are being evaluated for CAD.

Methods

The cardiac events (myocardial infarction, need for revascularization, or cardiac death) and all-cause mortality were retrospectively reviewed in 998 patients (mean age 65.5 ± 11.9 years, male 967) who underwent nuclear stress test. The fQRS on a 12-lead ECG included various RSR′ patterns (≥1 R′ prime or notching of S wave or R wave) without typical bundle branch block in 2 contiguous leads corresponding to a major coronary artery territory.

Results

All-cause mortality (93 [34.1%] vs 188 [25.9%]) and cardiac event rate (135 [49.5%] vs 200 [27.6%]) were higher in the fQRS group compared with the non-fQRS group during a mean follow-up of 57 ± 23 months. A Kaplan-Meier survival analysis revealed significantly lower event-free survival for cardiac events (P <.001) and all-cause mortality (P = .02). Multivariate Cox regression analysis revealed that significant fQRS was an independent significant predictor for cardiac events but not for all-cause mortality. The Kaplan-Meier survival analysis showed no significant difference between fQRS and Q waves groups for cardiac events (P = .48) and all-cause mortality (P = .08).

Conclusion

The fQRS is an independent predictor of cardiac events in patients with CAD. It is associated with significantly lower event-free survival for a cardiac event on long-term follow-up.

Section snippets

Methods

One thousand and thirty-four consecutive patients, who were referred for stress test at Veterans Affairs Medical Center, Indiana University, Indianapolis, between January 1998 and December 1999, were included in this retrospective study. These patients were being evaluated for CAD with either exercise or pharmacological nuclear stress testing. The study protocol was approved by the Institutional Review Board of Indiana University. The demographics, including history of significant CAD

Results

Of 1,034 consecutive patients who underwent stress testing, 36 patients were excluded because of an uninterpretable baseline ECG or stress imaging as well as incomplete stress protocol. Right bundle branch (n = 62), left bundle branch block (n = 38), and paced rhythm (n = 2) was included in the control group. Therefore, a final cohort of 998 patients (mean age 65.5 ± 11.9 years, male 967) were included in the study. The fQRS was present in at least 1 of the coronary artery territories in 273

New observations

Our study shows that fQRS is a strong independent predictor of major cardiac events. Also, approximately one-third (34.1%) of patients with fQRS die as compared with approximately one-fourth (25.9%) of patients without fQRS during a median follow-up of 5.5 years. This means that the presence of fQRS is associated with significantly higher (8.2% absolute and 31.7% relative) risk for all-cause mortality as compared with its absence. Although patients with fQRS have a significantly higher rate of

Conclusions

The presence of fQRS on a 12-lead ECG in patients with suspected or known CAD is associated with a significant increase in cardiac events and all-cause mortality as compared with its absence. The presence of fQRS is also an independent predictor of significantly higher cardiac events in these patients. There is no significant difference in event-free survival for cardiac events and all-cause mortality in the patients with fQRS as compared with those who show pathological Q waves on a standard

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