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Heart rate variability in patients with rheumatoid arthritis

Heart rate variability (HRV) is a useful tool for the detection of sympathetic-parasympathetic balance in the autonomic nervous system. Autonomic nervous system involvement in patients with rheumatoid arthritis (RA) has rarely been studied and has shown conflicting results. Our purpose was to determine if HRV showed changes in patients with RA in comparison with the normal population. Short-term analysis of HRV was performed for time-domain frequency in 42 patients with RA and 44 matched controls. In this analysis, patients displayed lower standard deviation of the mean than healthy subjects (P<0.0001). Patients tended to display higher pNN50 and root-mean-square of successive difference values than did healthy subjects, but these differences were not statistically significant (P>0.05). In frequency domain analysis, the spectral measures of HRV showed reduced high-frequency (HF) values and an higher low-frequency (LF) values; as a result, the ratio between low and high frequencies (LF/HF), representative of sympathovagal modulation, was significantly increased (P=0.001, P=0.012, and P=0.003, respectively). Our data suggest an increase in sympathetic control of the heart rate in patients with RA. This increased sympathetic activity could play a key role in the development of ventricular tachyarrhythmias in RA and may be related to the higher incidence of sudden death in this disorder.

Relationship between hemorheology and Glu(298)Asp polymorphism of endothelial nitric oxide synthase gene in patients with coronary artery disease.

This study aimed to investigate the relationship between endothelial nitric oxide synthase Glu(298)Asp gene polymorphism and hemorheological parameters. Red blood cell (RBC) deformability, aggregation were measured using an ectacytometry, whole blood, plasma viscosities were determined by a viscometer. Restriction fragment length polymorphism was used to detect polymorphism. Plasma nitrite, nitrate concentrations were determined by Griess method. The genotype distribution of the control group was as follows: 50 (67.5%) GG, 21 (28.4%) GT, 3 (4.1%) TT. A 48 (57.8%) of the patients with CAD had GG, 28 (33.7%) GT, 7 (8.5%) of them TT genotype. RBC aggregation index of CAD patients with G allele was higher and t½ lower compared to controls carrying the same allele. The amplitude of RBC aggregation of healthy subjects with T allele, who are under increased cardiovascular risk was lower compared to control subjects with G allele. The results of this study indicate that, alterations in RBC aggregation seem to be a consequence of CAD, more than being a preexisting cause. Additionally, some compensatory mechanisms by causing decrements in RBC aggregation, may help regulation of circulation in healthy individuals with high cardiovascular risk.

Right coronary artery arising as a terminal extension of the left circumflex artery (a rare coronary artery anomaly)

A single coronary artery is a very rare type of coronary artery anomaly that may present in various forms. A patient is presented in whom the right coronary artery coursed as the terminal branch of the left circumflex artery. This is the second case of this anomaly in the literature.

Decreased plasma adiponectin concentrations in patients with syndrome X

Objective — The levels of adiponectin, an anti-atherogenic protein, are decreased in patients with coronary artery disease. Syndrome X is associated with endothelial dysfunction, which is a key feature in the evolution of atherosclerosis.We sought to determine whether serum adiponectin levels are decreased in patients with syndrome X. Methods — Twenty-three syndrome X patients (14 men, 9 women) who presented with stable angina pectoris, had a positive non-invasive stress test or an abnormal myocardial perfusion scintigraphy single photon emission computed tomography (MPS SPECT) and a normal coronary angiogram, were included in our study, as were 17 asymptomatic healthy subjects (13 men, 4 women) with normal results from non-invasive stress testing. The serum adiponectin levels and lipid profiles of the patients and control subjects were determined with venous samples collected after a 12-hour fast. The results were analysed by a Mann Whitney U test. Results — Mean age (54.1 ± 11.8 y in patients and 59.8 ± 9.6 y in control subjects, P > 0.05) and body mass index (28.0 ± 3.3 in patients and 27.1 ± 4.2 in control subjects, P > 0.05) did not differ between the two groups. Adiponectin levels in patients with syndrome X (1.5 ± 1.1 mg/dl) were significantly lower than those in the control group (5.3 ± 2.9 mg/dl, P < 0.0001). Serum total cholesterol (TCHOL), triglyceride (TG), LDL, and HDL-cholesterol levels did not differ between the two groups (P > 0.05). Conclusion — Serum adiponectin levels were lower in patients with syndrome X, and these low adiponectin concentrations may cause endothelial dysfunction.Thus, patients with a marked drop in adiponectin levels may be considered at high risk for future coronary events and may therefore benefit from additional pharmacological treatment.