The autonomic nervous system (ANS) and cardiovascular function are intricately and closely related. One of the most frequently used diagnostic and prognostic tools for evaluating cardiovascular function is the exercise stress test. Exercise is associated with increased sympathetic and decreased parasympathetic activity and the period of recovery after maximum exercise is characterized by a combination of sympathetic withdrawal and parasympathetic reactivation, which are the two main arms of the ANS. Heart rate recovery after graded exercise is one of the commonly used techniques that reflects autonomic activity and predicts cardiovascular events and mortality, not only in cardiovascular system disorders, but also in various systemic disorders. In this article, the definition, applications and protocols of heart rate recovery and its value in various diseases, in addition to exercise physiology, the ANS and their relationship, will be discussed.

P-wave dispersion is defined as the difference between the maximum and the minimum P-wave duration recorded from multiple different-surface ECG leads. It has been known that increased P-wave duration and P-wave dispersion reflect prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses, which are well-known electrophysiologic characteristics in patients with atrial arrhythmias and especially paroxysmal atrial fibrillation. Extensive clinical evaluation of P-wave dispersion has been performed in the assessment of the risk for atrial fibrillation in patients without apparent heart disease, in hypertensives, in patients with coronary artery disease, in patients undergoing coronary artery bypass surgery, in patients with congenital heart diseases, as well as in other groups of patients suffering from various cardiac or non-cardiac diseases. In this paper, we aimed to summarize the measurement methods, current use in different clinical situations, strengths and limitations of the of P-wave dispersion.

Objective: This study was designed to determine the relationship between serum uric acid level and the presence and severity of coronary artery disease (CAD). Methods: A total of 1012 patients who underwent coronary angiography were included in this study. All patients were assessed for the presence of cardiovascular risk factors and ongoing medications. Serum uric acid and creatinine level, as well as a fasting lipid profile and fasting blood glucose, were measured in all patients before the procedure. The severity of CAD was assessed by the Gensini score. Results: Of 1012 patients (mean age, 59.4 ± 10.24 years), 680 were men (mean age, 58.7 ± 10.5 years) and 332 were women (mean age, 61.0 ± 9.51 years). Of the study patients, 703 (69%) were hypertensive, 292 (28.9%) were diabetic (DM), 304 (30%) had a smoking history, 306 (30%) had low high‐density lipoprotein cholesterol levels and 350 (34%) had hypertriglyceridaemia. CAD was present in 689 (68%) patients who were assessed by coronary angiography. One‐, two‐ and three‐vessel disease was detected in 32.6%, 32.5% and 34.9% of the patients respectively; left main coronary artery lesion was detected in 15% of the patients. A statistically significant difference in the mean uric acid concentrations was found between the patients with or without CAD [380 ± 121 μmol/l (6.39 ± 2.04 mg/dl) vs. 323.5 ± 83.2 μmol/l (5.44 ± 1.40 mg/dl) p < 0.001]. Based on logistic regression analysis, the increased serum uric acid level was found to be associated with the presence of CAD in both men and women (p < 0.001). The increased serum uric acid level was also found to be associated with the severity of CAD in both men and women based on multivariate linear regression analysis (p < 0.001). Conclusion: In conclusion, serum uric acid level was found to be associated with the presence and severity of CAD.

Background: Increasing evidence‐based indications for the implantation of permanent pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) have led to an increase in the rate of device infections. The aim of the present study was to evaluate infection frequency, clinical characteristics, risk factors, and microbiologic and therapeutic features in patients with PM/ICD infections.Hypothesis: Clinical and demographic characteristics of the patients can affect the PM/ICD infections.Methods: The PM/ICD infection group consisted of 57 patients diagnosed and treated with PM/ICD infections in our hospital. The control group in this case‐control study consisted of 833 patients in whom a PM or ICD had been implanted and no infections were noted.Results: Patients with PM/ICD infections (median age 65 years; range, 18–104 years) were older than those without PM/ICD infections (median age 58 years; range, 18–86 years; P = 0.005). The percentage of generator replacement was higher in the PM/ICD infection group compared with the control group (16% vs 8%, P = 0.003). Independent predictors of PM/ICD infections were advanced age (>60 years; odds ratio [OR]: 2.5, 95% confidence interval [CI]: 1.2–4.0, P = 0.021) and device revision (OR: 3.8, 95% CI: 1.5–5.5, P = 0.002). Primary antibiotic prophylaxis during the procedure reduced the risk for PM/ICD infection (OR: 0.5, 95% CI: 0.4–0.8, P = 0.011).Conclusions: PM/ICD infections occur in a significant number of patients. It is important to be aware of the risk factors for PM/ICD infections so that patients with an increased risk can be identified and preventive measures can be implemented. Copyright

This study examined the effects of low dialysate sodium on endothelial dysfunction (ED) as measured by flow-mediated dilatation (FMD) of brachial artery in haemodialysis (HD) patients. Thirty HD patients (17 men; mean age: 48.4 ± 17.8 years) were studied. Subjects underwent two consecutive 6-week HD periods. Dialysate sodium was 143 mEq/L in the first period (standard Na HD) and 137 mEq/L in the second period (low Na HD). After each period, we performed FMD, echocardiographic evaluation and 24-h ambulatory blood pressure monitoring (ABPM). Interdialytic weight gain (IDWG), levels of pre- and post-dialysis blood pressure (BP), and dialysis-related symptoms were monitored during the study. Per cent FMD was significantly greater (P < 0.05) after low Na HD (9.3 ± 6.2) compared with standard Na HD (5.7 ± 6.2). IDWG was significantly lower during low Na HD (2.35 ± 0.86 kg versus 2.71 ± 0.89 kg; P < 0.001). BP control was improved during low Na HD, as assessed by ABPM (128.2/77.5 mmHg versus 132.4/80.8 mmHg). Dialysis-related symptoms were more frequent during low Na HD (P < 0.05). There was no change in left ventricular mass after reducing dialysate sodium. Reducing dialysate sodium concentration reduced ED, and provided better control of IDWG and BP, but increased dialysis-related symptoms.