Ambulatory blood pressure monitoring provides information about the day-night blood pressure profile, which can be divided into dipping and non-dipping pattern. Non-dipping hypertension is recently thought to have increased cardiovascular risk and outcomes than dipping hypertension. The dipping pattern is explained by physiological changes in circadian rhythm, while the pathomechanism of non-dipping hypertension is not fully understood. Is it considered to be a result of many factors, such as: sympathetic nervous system overactivation, which can be accompanied by impaired parasympathetic nervous system response, obesity, concurrent diabetes mellitus and metabolic syndrome. Moreover abnormalities of hormones levels such as melatonin, catecholamines, thyroid and parathyroid hormones are connected to occurrence of non-dipping hypertension. Other widely discussed problem is obstructive sleep apnoea and its influence on circadian rhythm changes. Also dysfunction in activity of renin-angiotensin-aldosterone axis is thought to cause non-dipping pattern. There are some studies that indicate on role of inappropriate sodium intake in mentioned pathology. The chronic kidney disease and relationship with non-dipping hypertension will be also described. The last considered factor is influence of age on the development of non-dipping hypertension. key words: circadian blood pressure profile, blood pressure regulation, chronobiology, nocturnal hypertension, non-dipping pathomechanism

Due to high prevalence of hypertension (HT) in worldwide population, all aspects of this disease are studied in order to understand its pathogenesis and the influence on human body, as well as in order to find proper treatment. Impaired balance of autonomic nervous system (ANS) is taken into account as one of the main causes elevating blood pressure (BP). It seems that over-activation of sympathetic nervous system (SNS) is the most important factor in pathogenesis of HT. There are some methods which allow us to measure the sympathetic and parasympathetic nervous system activity. Some of them are described below and the influence of impaired ANS balance on HT development is presented. Many different, natural and pathologic factors can cause SNS response, so the measurement of the sole ANS activity cannot fully answer the question about the pathomechanism underlying HT. In this paper, we present some hypotheses regarding possible mechanisms of the disease progression. In primary HT, impairment of baroreceptors response is considered one of such mechanisms. Another one is the influence of hyperinsulinemia on the activation of SNS in insulin resistant patients. A few other factors are considered, like obesity, salt intake, sodium retention and alcohol intake and they are described briefly in our paper. In secondary hypertension, SNS can be activated indirectly by comorbidities, and this pathomechanism is also discussed.

Background: The frequency of cardiac implantable electronic device (CIED) implantations is constantly increasing. Pericardial effusion (PE) and tricuspid regurgitation (TR) may occur after CIED implantation. The aim of the present study is to evaluate the prevalence and risk factors for new occurrences or progression of TR and PE early after CIED implantation. Methods: This is an ongoing , single-center, observational study of patients after their first CIED implantation, with an echocardiographic evaluation within 60 days before and 7 days after the procedure. Data are presented for first 110 consecutive patients who underwent CIED implantation from August 2015 to July 2016. Results: Median age was 75 years, and 44% were women. In total, 87 (79%) pacemakers, 21 (19%) implantable cardioverter-defibrillators and 2 cardiac resynchronization therapy devices were implanted. After CIED implantation, there was TR progression in 17 (16%) patients: 5 patients developed moderate TR, none developed severe TR. An increase in TR was more often observed after implantations performed by operators in training than by certified operators (35% vs. 12%, p = 0.02). New PE after the procedure was observed in 8 (7%) patients and was trivial (< 5 mm) in all cases. Patients with new PE after implantation had lower baseline hemoglobin levels and tended to be women. Conclusions: New PE and an increase in TR severity are rare complications early after CIED implantation. Operator experience might be related to TR progression. Increasing the number of patients in the current ongoing study will allow a more reliable assessment of the prevalence and risk factors of these complications.