The importance of frontal QRS-T angle for predicting non-dipper status in hypertensive patients without left ventricular hypertrophy.

BACKGROUND: Frontal QRS-T angle is a novel marker of myocardial repolarization, and an increased frontal QRS-T angle associated with adverse cardiac outcomes. Non-dipper hypertension is also associated with adverse cardiac outcomes. This study aimed to investigate the relationship between frontal QRS-T angle and non-dipper status in hypertensive patients without left ventricular hypertrophy (LVH). METHODS: This study included 122 hypertensive patients without LVH. Patients were divided into two groups: dipper hypertension and non-dipper hypertension. The frontal QRS-T angle was calculated from 12-lead electrocardiography. RESULTS: Frontal QRS-T angle (47.9° ± 29.7° vs. 26.7° ± 19.6°, P < 0.001) was significantly higher in patients with non-dipper hypertension than in patients with dipper hypertension. In addition, frontal QRS-T angle was positively correlated with sleeping systolic (r = 0.211, P = 0.020), and diastolic (r = 0.199, P = 0.028) blood pressures (BP), even if they were weak. Multivariate analysis showed that the frontal QRS-T angle was independent predictor of non-dipper status (QR: 1.037, 95% CI: 1.019-1.056, P < 0.001). CONCLUSION: Frontal QRS-T angle is independent predictor of non-dipper status in hypertensive patients without LVH.

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.

Evaluation of serum prolidase activity in patients with slow coronary flow.

INTRODUCTION: Slow coronary flow (SCF) is described as the slow passage of contrast to distal coronaries despite anatomically normal coronary arteries. It has been shown that increased serum prolidase activity (SPA) correlates with collagen turnover. Increased collagen turnover might be associated with the development of atherosclerotic plaques. AIM: To investigate the relationship between serum prolidase activity and slow coronary flow. MATERIAL AND METHODS: This cross-sectional study included 40 SCF patients (mean age: 55.0 ±9.5 years, 20 females) and 40 controls (mean age: 53.9 ±8.2 years, 21 females) with normal coronary anatomy and normal coronary flow. The Thrombolysis in Myocardial Infarction (TIMI) frame-count (TFC) method was used for SCF diagnosis. Serum prolidase activity was measured spectrophotometrically, and the relevant parameters were compared between the groups. RESULTS: There were no statistically significant differences between the SCF and control groups in terms of basic demographic, clinical, and laboratory data. However, the SPA was significantly higher in the SCF group compared to the control (702.7 ±13.8 and 683.9 ±13.2 respectively, p<0.001). Serum prolidase activity was significantly correlated with the mean TFC (r=0.463, p<0.001). The overall findings of this study support the predictive accuracy of the serum prolidase activity in our cohort, with a statistically significant ROC value of 681.3. CONCLUSIONS: Our study showed that SPA was increased in SCF patients. The activity of this enzyme was significantly correlated with the mean TFC.

Prolidase activity in patients with coronary artery aneurysm.

Decreased collagen biosynthesis and increased collagenolysis may induce aneurysmal progress in arterial walls. Prolidase plays a role in collagen synthesis. In this study, we sought to evaluate whether there is a correlation between nonatherosclerotic coronary artery aneurysms (CAAs) and prolidase activity. A total of 174 CAAs were diagnosed in 144 (2.1%) patients among 6845 coronary angiographies performed between 2009 and 2012. In all, 23 (15.9%) patients had nonatherosclerotic aneurysms. Prolidase activity was compared to the results of 19 healthy volunteers with normal coronary arteries. Demographic parameters were similar between the groups. Mean prolidase activity was 241.6 ± 54.4 mU/mL in the coronary aneurysm group and 730.3 ± 243.1 mU/mL in the control group (P < .001). The incidence of CAAs ranges between 0.3% and 5.3% in the general population. Decreased prolidase activity may reduce collagen biosynthesis that may contribute to aneurysm formation.