Contribution of fragmented QRS on myocardial perfusion imaging in the assessment of functionally significant coronary artery stenoses.

OBJECTIVE The evaluation of the functional significance of coronary artery stenosis is of great clinical importance in patient management or for decisions concerning coronary intervention. Recently, fragmented QRS (fQRS) on electrocardiography (ECG) has been introduced as a predictor of myocardial scarring as well as myocardial ischaemia in coronary artery disease. We aimed to investigate any additive value of fQRS to myocardial perfusion SPECT in evaluating the functional significance of the intermediate degree of coronary stenosis. PATIENTS AND METHODS Patients who were referred for myocardial perfusion imaging (MPI) to evaluate the functional significance of intermediate (40-70%) coronary artery stenosis were analyzed retrospectively; 102 patients were included in the study. ECG records were evaluated to detect fQRS. MPI was interpreted visually and semiquantitatively by two nuclear medicine physicians blinded to the electrocardiographic findings. Summed stress scores (SSS), summed rest scores and summed difference scores (SDS) were calculated according to the 17-segment model. RESULTS The mean age of the patients was 62.56±9.5 years, and 64 were males (62.7%). Ischaemia was detected in 30 patients, and the frequency of fQRS was significantly higher in patients with ischaemia than in patients with normal perfusion (54.8% vs. 23.8%, respectively; p<0.001). Myocardial scarring was detected in 15 patients, 7 of whom had coexistent myocardial ischaemia. fQRS was positively correlated with the SSS (r=374, p=0.001), SDS (r=0.460, p=0.001) and summed motion score (r=0.228, p=0.024). fQRS was an independent predictor of myocardial ischemia in multivariate analyses (OR=11.181; CI=3.900-32.057; p<0.001). CONCLUSIONS The presence of fQRS on ECG is associated with myocardial ischaemia in patients who had an intermediate degree of coronary stenosis.