Effect of heart rate and pacing mode on QRS fragmentation

Fragmented QRS as a marker of coronary atherosclerosis severity evaluated by the Gensini score

BACKGROUND

QRS fragmentation (fQRS) represents a marker of local myocardial fibrosis, especially in patients with CAD (coronary artery disease). However, little is known about the association between fQRS and the severity of coronary atherosclerosis as defined by the Gensini score.

OBJECTIVE

To identify the angiographic and echocardiographic characteristics of patients with suspected CAD depending on the location and extent of fQRS.

METHODS

A total of 178 patients who underwent coronary angiography were included in the study. fQRS was defined as the presence of RSR' and/or notching of the R/S wave (if QRS<120ms) or≥2 notches of the R/S wave (if QRS≥120ms). All patients were divided into three groups: non-fQRS; fQRS in 1-2 and≥3 leads.

RESULTS

Statistically significant differences in the LVEF (left ventricular ejection fraction, P=0.009) and the degree of coronary atherosclerosis severity (P=0.008) were found among 3 groups. The median Gensini score was 7 in non-fQRS group (minimal CAD) and >20 in other groups (severe CAD). Both the anterior and lateral fQRS groups had a lower LVEF compared to no fQRS (P=0.039 and P=0.01, respectively). The median Gensini score was significantly higher in case of the lateral fQRS (P=0.037). fQRS in≥1 lead was associated with coronary occlusion (OR 2.1, 95% CI: 1.1-4.1, P=0.038).

CONCLUSIONS

The presence of fQRS, particularly in lateral leads, can be a useful noninvasive marker of severe coronary atherosclerosis. Patients with≥1 fragmented lead have a lower LVEF, a higher Gensini score and a two-fold increased risk of occlusion.