Presence of fragmented QRS and its correlation with myocardial performance index in patients with nephrotic syndrome.

Objective: More cardiovascular events are seen in nephrotic syndrome (NS) patients than in the normal population. Fragmented QRS (fQRS) includes various RSR' patterns with different morphologies of the QRS complexes with or without the Q wave on a resting 12-lead ECG. A relationship between the presence of fQRS and myocardial function impairment has been shown in several studies. The purpose of this study was to evaluate the presence of fQRS in this patient group and the relationship with myocardial functions.
Methods: Thirty-four NS patients were included in the cross-sectional study. Demographic data were recorded, and electrocardiograms (ECGs) were analyzed for the presence of fQRS following investigation of biochemical parameters and 24-h protein excretion. In addition to classic echocardiographic parameters, the myocardial performance (Tei index) was calculated as an indicator of cardiac function. For comparison of group's data Student's t-test and Mann-Whitney U test were used. Multiple linear regression analysis was performed for parameters affecting presence of fQRS.
Results: We identified fQRS in half of our patients group. Patients with fQRS had significantly greater proteinuria level and Tei index than those without (p<0.05 and p<0.001, respectively). Tei index was also affected presence of fQRS (p<0.05, β=0.45, R2=0.32) and positively correlated with proteinuria levels (p<0.05 r=0.366).
Conclusion: We demonstrated, for the first time in the literature, that the determination of fQRS in patients with NS in surface ECG, an easily accessible technique, can be used as a parameter in the prediction of myocardial functions.