The relationship between fragmented QRS and non-dipper status in hypertensive patients without left ventricular hypertrophy

Background: Fragmented QRS (fQRS) has been shown to be associated with poor outcome in various cardiovascular diseases. Non-dipper hypertension is also associated with increased cardiovascular mortality. The aim of our study is to investigate the relationship between fQRS and non-dipper status in hypertensive patients without left ventricular hypertrophy (LVH). Methods: This study included 106 hypertensive patients without LVH. Patients were divided into two groups: dipper hypertension and non-dipper hypertension. The presence of fQRS was analyzed from surface electrocardiography. Results: Frequency of fQRS (56% vs. 19.6%, p < 0.001) and mean number of leads with fQRS (1.9 +/- 1.7 vs. 0.6 +/- 1.0, p < 0.001) were significantly higher in patients with non-dipper hypertension compared to dipper hypertension. In addition, the number of leads with fQRS was positively correlated with systolic (r = 0.334, p < 0.001) and diastolic (r = 0.280, p = 0.004) blood pressures (BP). By a multivariate regression analysis, fQRS (OR: 5.207, 95% CI: 2.195-12.353, p < 0.001) was found to be independent predictor of non-dipper status. Conclusion: fQRS is independent predictor of non-dipper status in hypertensive patients without LVH. Also, the higher number of leads with fQRS is associated with higher sleep systolic and diastolic BPs.