Background: QRS complex fragmentations can frequently be seen on routine ECG with narrow or wide QRS complex. Fragmented QRS complexes (fQRS) are defined as various RSR' patterns (≥ 1 R' or notching of S wave or R wave) in two contiguous leads corresponding to a major coronary artery territory. In previous studies, fQRS has been associated with increased morbidity and mortality, sudden cardiac death and recurrent cardiovascular events. The causative relationship between fQRS and cardiac fibrosis has been shown, but it has not been extensively studied whether there are different mechanisms for the development of fQRS.

Aim: To interrogate the relationship between systemic inflammation and the presence of fQRS in patients with stable angina pectoris.

Methods: A total of 353 eligible patients who underwent coronary angiography with a suspicion of coronary artery disease (CAD) at our institution between April 2010 and December 2010 were enrolled consecutively. All patients had angina pectoris or angina equivalent symptoms with either a positive treadmill test or myocardial perfusion study. Patients with recent acute coronary syndrome either with or without ST-segment elevation, significant organic valve disease, and patients having any QRS morphology with QRS duration ≥ 120 ms, as well as patients with permanent pacemakers, were excluded from the study.

Results: Patients with fQRS had older age (p = 0.01), higher C-reactive protein (CRP) (p < 0.001), longer QRS time (p < 0.001) and more severe CAD (p < 0.001) compared to patients with non-fragmented QRS. When we performed multiple logistic regression analysis, we found that the fragmentations in QRS complexes were positively related with increased CRP (OR: 3.8, 95% CI 1.573.9.278, p = 0.003), and QRS duration (OR: 1.1, 95% CI 1.008.1.101, p = 0.019) and negatively related with left ventricular ejection fraction [%] (OR: 1.0, 95% CI 0.914.0.992, p = 0.020).

Conclusions: In our study, we found that fQRS was independently related with increased CRP and QRS duration as well as left ventricular systolic dysfunction. Fragmented QRS, which may come about as an end effect of inflammation at cellular level, can represent increased cardiac risk by different causative mechanisms in patients with stable CAD. In addition, fragmentations on ECG may be useful for identifying patients who should be investigated and treated for their increased inflammatory status and possible chronic infections.