[Is there circadian variation of big endothelin and NT-proBNP in patients with severe congestive heart failure?]. / Existuje diurnální variabilita big endotelinu a NT-proBNP u nemorných s tezkým chronickým srdecním selháním?

INTRODUCTION: Circadian rhytmus have long been recognized to occur in many biologic phenomena, including secretion of hormones as well as autonomic nervous system. There is increasing evidence that circadian rhythms have been also found in cardiovascular events, for example, myocardial infarction, sudden cardiac death as well as stroke have shown a circadian pattern of the distribution. The pathophysiology and the mechanism underlying these variations are the focus of much investigation, while i tis not full understood up to date. Heart rate, blood pressure, neurohumoral vasoactive factors, such as plasma norepinephrine levels and renin activity, and probably also contractility are increased in the morning hours. THE AIM OF OUR STUDY: To evaluate the circadian variability of plasma big endothelin and NT-proBNP level in patients with severe heart failure. PATIENTS: 13 patients with severe heart failure, stable for at least one month, male/female--8/5, NYHA III/IV--11/2, mean left ventricle ejection fraction 23 +/- 5%, mean cardiothoracic ratio 59 +/- 7%, all treated with RAAS blocade (11 x ACE-I, 2x ARB), all treated with diuretics, 12 patients treated with beta-blockers, 7 with digoxin. The cause of heart failure was ischemic heart disease (9) or dilated cardiomyopathy (4). METHODS: Blood samples for big endothelin and NT-proBNP were taken every two hours during a standartised daily regime. RESULTS: Mean plasma level of big endothelin (ranging from 1.25 to 1.71 pmol/l) had significant diurnal variability (upper limit of normal values 0.7 pmol/l). Mean plasma level of NT-proBNP (ranging from 782 to 934 pmol/l) had no diurnal variability (upper limit of normal values of 350 pmo/l). SUMMARY: Plasma level of NT-proBNP is stable during 24 hours and shows no circadian variability. Plasma big endothelin showed a morning peak after a systematic increase during bed rest. NT-proBNP could be evaluated any time during the day, big endothelin sample should be taken during standartised condition.

[Peroral hormonal contraception and risk of venous thromboembolism]. / Perorální hormonální antikoncepce a riziko vzniku zilního tromboembolizmu.

Oral contraceptives increase the risk of thromboembolism. Recent studies have indicated that the risk of thromboembolic disease in users of combined oral contraceptive pills varies not only with estrogen dose, but also with the type of gestagen in pills with the same estrogen dose. We describe 8 women from our intensive care unit who developed a deep venous thrombosis while on oral contraceptives. The aim of this article is also to discuss other risk factors for the potential risk of venous tromboembolism in users of combined oral contraceptive.

[Hypertension in HIV positive patients]. / Hypertenze u HIV pozitivních pacientu.

Survival of HIV-positive patients on highly active antiretroviral therapy (HAART) has significantly improved. Although traditional heart complications of the infection such as pericarditis or myocarditis has become rather rare owing to the therapy, wide range of metabolic abnormalities have been described. We focused on the evaluation of prevalence of hypertension among HIV positive patients with respect to their high cardiovascular risk. We examined 40 HIV positive patients (28 males and 12 females) followed in AIDS center in Brno. All probands underwent 24-hour ambulatory blood pressure monitoring as a part of their cardiological examination. 40 age- and gender-matched healthy controls were recruited. We evaluated the average value of systolic (SBP) and diastolic (DBP) blood pressure as well as the average value of heart rate (HR) within 24 hours of monitoring. Following values were found in the group of healthy controls: SBP 124.1 +/- 8.6 mm Hg, DBP 71.6 +/- 6.9 mm Hg and HR 67.9 +/- 9.7/min. HIV positive patients presented with the following values: SBP 118.5 +/- 9.3 mm Hg, DBP 76.8 +/- 5.7 mm Hg a HR 78.6 +/- 9.7/min. All the differences were statistically significant at p < 0.05. We diagnosed 14 patients with hypertension defined as SBP higher than 125 mm Hg and/or DBP higher than 80 mm Hg in both of the groups. Prevalence of hypertension in HIV positive patients was comparable to that seen in healthy controls. HIV positive patients had lower SBP but higher DBP and HR.

[Variability of plasmatic levels of big endothelin and NT-proBNP in patients with heart failure in a chronic haemodialysis programme]. / Variabilita plazmatických hladin big endotelinu a NT-proBNP u nemocných se srdecním selháním v chronickém hemodialyzacním programu.

Inter-dialysis variability in levels of big endothelin and NT-proBNP in plasma were studied in 22 patients with established systolic and/or diastolic dysfunction of the left cardiac ventricle assigned to a chronic haemodialysis programme. The plasmatic level of NT-proBNP in all patients was practically unchanged. There was a falling trended between haemodialysis treatments but this was not statistically significant and in absolute values clinically insignificant. Fluctuations were found between individuals but on average all values were stable and high in the pathological range. No significant changes in the plasmatic level of big endothelin were found either. The average levels were again stable and insignificant and the indicated trend did not achieve clinical or statistical significance. The values were once again high in the pathological range. Plasmatic levels of NT-proBNP and big endothelin do not vary according to the phase of the dialysis cycle and mainly reflect the long-term condition of endothelium failure and long-term stress in the left ventricle. Concentrations are not affected by changes in volume or uraemia between dialysis treatments and the suggested trend towards a fall in NT-proBNP and a rise in big endothelin does not have a clear explanation. In any case, this trend remained within the pathological range and is probably not clinically significant.