The pure effects of obstructive sleep apnea syndrome on cardiac autonomic functions: heart rate turbulence analysis.

OBJECTIVES: To demonstrate the pure effect of obstructive sleep apnea syndrome (OSAS) on cardiac autonomic function (CAF) using heart rate turbulence (HRT) parameters. PATIENTS AND METHODS: A total of 64 patients with OSAS and 30 age- and gender-matched healthy subjects were enrolled. All subjects had normal coronary arteries and were free from diabetes mellitus (DM) and hypertension (HT). The HRT parameters (TO, turbulence onset; TS, turbulence slope) were obtained from 24-h ambulatory electrocardiogram (ECG) recordings. HRT parameters were compared between groups, and the relationship between HRT and the apnea-hypopnea index (AHI) was examined. RESULTS: No between-group differences were found in age or gender. Mean TO was significantly higher in the OSAS group than in healthy controls (0.89 ± 0.5, -0.08 ± 0.26; p < 0.001; respectively). The mean TS did not differ between the two groups (2.81 ± 3.06 versus 3.14 ± 2.33; p = 0.212). The AHI was positively correlated with TO (r = 0.845, p < 0.001). The multiple logistic regression analysis revealed that after adjustment for other variables, TO was a significant and independent predictor of AHI, OR 2.394 (95% CI: 1.596-3.591). CONCLUSIONS: HRT (TO in particular) is correlated with AHI. Thus, impaired HRT may be an important factor underlying the occurrence of arrhythmia and sudden cardiac death in patients with OSAS.

The effect of radiofrequency ablation treatment on quality of life and anxiety in patients with supraventricular tachycardia.

AIM: Paroxysmal supraventricular tachycardia (PSVT) has been shown to be associated with poor outcome in psychological status and quality of life. This study aimed to assess the quality-of-life and anxiety in patients with PSVT and to investigate the influence of radiofrequency ablation (RFA) treatment on these parameters. MATERIALS AND METHODS: Fifty patients with newly diagnosed PSVT with electrophysiologic study and treated with RFA, were enrolled in the study and 50 healthy age-and sex-matched individuals. The brief version of World Health Organization Quality of Life Scale and the state-trait anxiety inventory were administered to controls and all patients before and three months after the RFA procedure. RESULTS: At baseline, in comparison with the control group, the patients with PSVT exhibited greater anxiety average scores (p < 0.05). After RFA procedure, the patients with PSVT exhibited significant improvement in anxiety, quality of life and health satisfaction scores. Statistically significant difference between the controls and the patients in respect to state and trait anxiety average scores disappeared after treatment (p > 0.05). CONCLUSIONS: In this study, normalization of anxiety and quality of life is associated with RFA treatment for patients with PSVT. This finding need to be confirmed by larger scale clinical trials with long-term quality of life follow-up in higher number of patients.

HDL-cholesterol is associated with systemic inflammation in cardiac syndrome X.

AIM: Microvascular inflammation is associated with cardiac syndrome X (CSX). High-density lipoprotein cholesterol (HDL-C) reveals antiatherogenic features with stimulating endothelial NO production, inhibiting oxidative stress and vascular inflammation. We investigated relationship between HDL-C and inflammatory markers in CSX. METHODS: Hundred patients with CSX and control group of 80 subjects were evaluated. Hematologic indices, lipid levels and C-reactive protein (CRP) levels were studied in patients underwent coronary angiography. RESULTS: CRP levels were higher in CSX group than control group (4.59 ± 3.82 mg/dL vs. 2.48 ± 1.32 mg/dL, P<0.001). HDL-C was significantly lower in CSX group compared to control group (36.5 ± 4.0 mg/dL vs. 47.5 ± 12.7 mg/dL, P=0.008). White blood cell (WBC) count was higher in CSX group than in control group. Neutrophil-lymphocyte ratio (NLR) was found significantly increased in CSX group as compared to control group. On multivariate linear regression, lower HDL-C was found to be a significant predictor of higher NLR in patients with CSX independent from other clinical and biochemical variables. CONCLUSION: Lower HDL-C is associated with systemic inflammation in CSX. In patients with typical angina and normal epicardial coronaries,HDL-C and inflammatory markers should be investigated; one of the goals of treatment should be raising HDL-C.