Intra-left ventricular systolic asynchrony in patients with overt hyperthyroidism

Hyperthyroidism causes a variety of adverse effects on the cardiovascular system. Left ventricular (LV) asynchrony is defined as loss of the simultaneous peak contraction of corresponding cardiac segments. The aim of this study was to assess systolic asynchrony in patients with overt hyperthyroidism. Asynchrony was evaluated in 27 patients with overt hyperthyroidism and 21 controls. All the patients and controls were subjected to a tissue synchronization imaging (TSI). The time to regional peak systolic tissue velocity (Ts) in LV by the six-basal-six-mid-segmental model was measured on ejection phase TSI images and four TSI parameters of systolic asynchrony were computed. All TSI parameters of LV asynchrony increased in hyperthyroid patients compared to controls: the standard deviation (SD) of the 12 LV segments Ts (35.7±14.4 vs 20.1±10.1, P<0.0001); the maximal difference in Ts between any 2 of the 12 LV segments (111.9±40.7 vs 65.9±30.7, P<0.0001); the SD of the 6 basal LV segments (31.2±18.2 vs 16.8±9.7, P=0.01); and the maximal difference in Ts between any 2 of the 6 basal LV segments (76.6±42.0 vs 44.4±25.7, P=0.005). Patients with overt hyperthyroidism present evidence of LV asynchrony by TSI.     

Impairment of flow-mediated vasodilatation of brachial artery in patients with Cushing's Syndrome

Background Cushing’s Syndrome (CS) is associated with excess and premature cardiovascular disease. Endothelial dysfunction is the initiating event in the development of atherosclerosis. Endothelial function is assessed by flow-mediated dilatation (FMD) of brachial artery. The aim of this study was to assess FMD in patients with CS. Methods We prospectively evaluated 22 patients with CS (12 women, 10 men; aged 42 ± 11 years, serum cortisol 28.2 ± 14 μg/dl, 24-h urinary free cortisol (UFC) 269 ± 92 μg/day), and 23 control subjects (13 women, 10 men; aged 43 ± 10 years, serum cortisol 14 ± 4 μg/dl, 24 h cortisol 60 ± 22 μg/day). Endothelial function, measured as FMD of the brachial artery using ultrasound, was calculated in two groups. Endothelial function was evaluated by assessing 1-min postischemic FMD of the brachial artery. Results FMD was lower in patients with CS than that in those without (11.7 ± 4.8% vs. 15.8 ± 3.2%, P = 0.0001, respectively). There was no significant difference between two groups regarding baseline diameter of brachial artery. But, hyperemia diameter was lower in patients with CS than without CS (3.6 ± 0.22 mm vs. 3.9 ± 0.19 mm, P = 0.04, respectively) Conclusion Endothelium-dependent FMD may impair in patients with CS compared to controls. Measurement of endothelial function may identify high-risk individuals early and therapy to reduce or retard endothelial dysfunction in patients with CS may lead to decreased cardiovascular morbidity and mortality.     

Identifying cardiovascular risk factors in a patient population with coronary artery ectasia

Coronary artery ectasia (CAE) is frequently considered as a form of coronary artery disease. Cardiovascular risk factors were determined in a patient population with CAE. The 51 patients with isolated CAE (group 1), 61 patients with CAE coexisting with significant coronary stenosis (group 2), and 62 subjects with significant coronary stenosis (group 3) were included in the study, and the distribution of cardiovascular risk factors was compared. Thirty of 51 patients with isolated CAE had presented with typical angina pectoris, 8 patients with unstable angina pectoris, and 13 patients had atypical chest pain or palpitation. The 21 of 51 patients with isolated CAE had definitive positive treadmill exercise test results. Positive family history was similar in each group. The history of smoking was similar in group 1 and group 2 but higher than group 3. Frequency of hypertension was similar in group 1 and group 2 but higher than that in group 3. Frequency of diabetes mellitus was similar in group 1 and group 2 but lower than group 3. Plasma lipid levels and the number of patients with lipid disturbances were also similar in each group. In addition, C-reactive protein (CRP) levels were above the normal limits and there was no difference among groups with respect to plasma CRP levels. CAE appears to be associated with traditional cardiovascular risk factors such as hypertension, smoking, and hyperlipidemia. In addition, elevated CRP level in patients with CAE may suggest the role of inflammatory process in development of CAE.     

Stobadine protects rat kidney against ischaemia/reperfusion injury

1. Ischaemia-reperfusion (I/R) injury, one of the main causes of acute renal failure, still needs satisfactory treatment for routine clinical application. Stobadine, a novel synthetic pyridoindole anti-oxidant, has the ability to reduce tissue injury induced by mechanisms involving reactive oxygen species during I/R. The aim of the present study was to determine the effects of stobadine on renal I/R injury. 2. Forty male Wistar rats were randomly divided into four groups as follows: sham, I/R, stobadine treated and I/R + stobadine treated. Stobadine (2 mg/kg, i.v.) was given intravenously to two groups of rats. The stobadine-treated group was treated with stobadine following sham operation before the abdominal wall was closed, whereas the I/R + stobadine group received stobadine at the beginning of reperfusion. Renal I/R was achieved by occluding the renal arteries bilaterally for 40 min, followed by 6 h reperfusion. Immediately thereafter, blood was drawn and tissue samples were harvested to assess: (i) serum levels of blood urea nitrogen and creatinine; (ii) serum and/or tissue levels of malondialdehyde (MDA), glutathione (GSH), glucose 6-phosphate dehydrogenase (G-6PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR) and glutathione peroxidase (GPx); (iii) renal morphology; and (iv) immunohistochemical staining for P-selectin. 3. Stobadine was able to significantly attenuate the renal dysfunction as a result of renal I/R injury. Ischaemia-reperfusion resulted in a significant increase in serum and kidney MDA levels and a decrease in serum and kidney GSH. Stobadine treatment at the beginning of reperfusion attenuated both the increased MDA levels and decreased GSH secondary to I/R injury. In addition, the decreased G-6PD activity observed after I/R was significantly attenuated by stobadine treatment. Stobadine did not alter 6-PGD activity after I/R. Neither GR nor GPx activity was significantly changed in the I/R alone or the I/R + stobadine groups compared with the sham group. In addition, stobadine decreased the morphological deterioration and high P-selectin immunoreactivity secondary to renal I/R injury. 4. A pyridoindole anti-oxidant, stobadine exerts a renal protective effect in renal I/R injury, which is probably due to its radical-scavenging and anti-oxidant activities.