Is the resistance of large conduit arteries also decreased in thyrotoxic patients with Graves' disease?

Longitudinal arterial resistance (RL) originates during blood flow in large conduit arteries while peripheral resistance (RP) reflects the tension of arterioles. Using a new noninvasive ultrasonic system of assessment of mechanical properties of arterial walls, we aimed to discover whether both RL and RP are affected by excess of thyroid hormones (TH). We compared two groups: hyperthyroid (Graves' group, n = 25) and euthyroid (control group, n = 23). RL and RP values were obtained from the analysis of the four-element lumped parameters model describing the vascular input impedance. The vascular input impedance was determined on the basis of simultaneous measurements of blood pressure, blood flow and arterial diameter using oscillometric and ultrasonic methods. RL and RP were lower in the Graves' group (3.71 +/- 1.98 versus 4.49 +/- 1.81 10(8)kgm(4)s(1), p < 0.05 and 8.43 +/- 3.56 versus 11.23 +/- 2.69 0(8)kgm(4)s(1), p < 0.00002, respectively). There was strong correlation between RP and TH in the Graves' group (r(s)= -0.6710, p = 0.000001 for RP and free triiodothyronine (FT3); r(s)= -0.4683, p < 0.001 for RP and free thyroxine [FT4]). This relationship remained significant after the statistical correction for total cholesterol (r(p)= -0.7064 p = 0.0000001 for RP and FT3). No similar correlation between RL and TH was found what suggests a different character of relations between TH and RL and between TH and RP.

The stiffness of the common carotid artery in patients with Graves' disease.

BACKGROUND: Thyroid hormone excess is accompanied by many cardiovascular symptoms. We hypothesised that mechanical properties of the large arteries are also involved in hyperthyroidism-induced cardiovascular changes and set out to investigate this further. METHODS: We compared 2 groups: one composed of hospitalized patients with newly diagnosed, non-treated Graves' disease (Graves' group) and the other (control group) composed of healthy persons or patients with euthyroid goiter (n=25 and n=23, respectively). We determined values of cross-sectional compliance (CC(100)), distensibility (DC(100)) and stiffness coefficients (alpha(100)) estimated for blood pressure P(n)=100 mmHg by measuring the blood pressure with the oscillometric method and measuring differences in the diameter of the common carotid artery with ultrasonographic vascular echo Doppler system. RESULTS: We found no differences in CC(100) (10.6 vs 10.3 10(-4)m(2)/Mpa), DC(100) (29.7 vs 29.6 1/Mpa) or alpha(100) (2.67 vs 2.72) between the 2 groups. However, there were strong correlations between all stiffness parameters and plasma thyroid hormone concentrations in the Graves' group (r(s)=0.4698, p<0.001 for DC(100), r(s)=0.4342, p<0.003 for CC(100), r(s)=-0.4698, p<0.001 for alpha(100) and fT3, respectively). This relationships remained significant after statistical corrections for age and lipid levels (r(p)=0.22, p<0.03 for DC(100) and fT3 or r(p)=-0.457, p<0.02 for alpha(100) and fT3, respectively). CONCLUSIONS: These results indicate that in the Graves' group the stiffness of the common carotid artery might be affected by the thyroid hormone level and the lower the level, the more severe the activity of the hyperthyroidism reflected by the plasma concentration of fT3 or fT4.

[T-vertical extension of the uterus in cesarean section]. / Dociecie macicy w trzonie ku górze w odwrócona litere 'T' podczas ciecia cesarskiego.

The objective of this study was to identify the indications for 'T' vertical extension in low transverse caesarean births, to determine complications during puerperium, blood loss, length of hospital stay and condition of newborn evaluated with Apgar score. 61 cases of extension were compared with 61 randomly selected women match for the date of delivery. Mann-Whitney Test and gamma 2-Test were used to compare both groups. The study showed the most common indications were difficulties in fetal extraction. Type of anaesthesia used during operation, blood loss and complications during puerperium didn't differ between both groups. 'T' extensions are safe and are not associated with prolonged hospital stays compared with controls. The condition of newborn evaluated with Apgar score is good in this group.