• MeSH
• arteriovenózní píštěl patofyziologie   diagnóza   komplikace   MeSH
• arteriovenózní zkrat metody   MeSH
• dialýza ledvin MeSH
• hemodynamika * fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• srdeční selhání * patofyziologie   diagnóza   MeSH
• vysoký srdeční výdej patofyziologie   etiologie   diagnóza   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• dopisy MeSH

Background: A large arteriovenous fistula (AVF) is a low-resistant circuit that affects organ perfusion and systemic hemodynamics even in standard conditions. The extent of its' effect in critical states has not been elucidated yet. We used norepinephrine to create systemic vasoconstriction, dobutamine to create high cardiac output, and rapid right ventricle pacing as a model of acute heart failure in a porcine model of high-flow AVF circulation. Methods: The protocol was performed on nine domestic female pigs under general anesthesia. AVF was created by connecting two high-diameter ECMO cannulas inserted in the femoral artery and vein. Continuous hemodynamic monitoring was performed throughout the protocol. Three interventions were performed-moderate dose of norepinephrine (0.25 ug/kg/min), moderate dose of dobutamine (10 ug/kg/min) and rapid right ventricle pacing to simulate low cardiac output state with mean arterial pressure under 60 mmHg. Measurements were taken with opened and closed arteriovenous fistula. Results: Continuous infusion of norepinephrine with opened AVF significantly increased mean arterial pressure (+20%) and total cardiac output (CO) (+36%), but vascular resistance remained virtually unchanged. AVF flow (Qa) rise correlated with mean arterial pressure increase (+20%; R = 0.97, p = 0.0001). Effective cardiac output increased, leading to insignificant improvement in organ perfusion. Dobutamine substantially increased cardiac output with insignificant effect on AVF flow and mean arterial pressure. Carotid artery blood flow increased significantly after dobutamine infusion by approximately 30%, coronary flow velocity increased significantly only in closed AVF state. The effective cardiac output using the heart failure model leading to decrease of carotid artery flow and worsening of brain and peripheral tissue oximetry. AVF blood flow also dropped significantly and proportionally to pressure, but Qa/CO ratio did not change. Therefore, the effective cardiac output decreased. Conclusion: In abovementioned extreme hemodynamic conditions the AVF flow was always directly proportional to systemic perfusion pressure. The ratio of shunt flow to cardiac output depended on systemic vascular resistance. These experiments highlight the detrimental role of a large AVF in these critical conditions' models.

• Publikační typ
• časopisecké články MeSH

Kontext: Pro stratifikaci rizika pacientů se srdečním selháním se začaly používat hemodynamické parametry. Srdeční výkon (cardiac power output, CPO) je ukazatelem výkonnosti srdce. Index srdeční síly (cardiac power index, CPI) vyjadřuje vztah srdečního výkonu a plochy tělesného povrchu. Cílem studie bylo prokázat prognostickou úlohu klidového CPI u pacientů s pokročilým chronickým srdečním selháním. Metody: Do studie byli zařazeni pacienti v pokročilém stadiu chronického srdečního selhání, s ejekční frakcí levé komory < 30 % a ve funkčních třídách III a IV, u nichž byla provedena katetrizace pravostranných i levostranných srdečních oddílů. Vyšetřeno bylo celkem 99 pacientů; jedinci, jimž byla implantována centrifugální pumpa k podpoře funkce levé komory (left ventricular assist device, LVAD) nebo u nichž byla provedena transplantace srdce (heart transplantation, HTx), byli ze studie vyloučeni, aby bylo možno stanovit délku přežití bez LVAD a HTx. Výsledky: Z 99 vyšetřených pacientů byl chirurgický výkon v souvislosti s LVAD nebo HTx proveden u 43 pacientů. Ze zbývajících 56 pacientů jich během sledování s mediánem délky 16 měsíců zemřelo 19 (33,9 %). Hodnota CPI byla spojena s úmrtím ze srdečních příčin (0,32 vs. 0,42, p = 0,003). Mezní hodnota CPI z hlediska mortality byla 0,41 (senzitivita 89,5 % a specificita 56,8 %). Snížená hodnota CPI (< 0,41 W/m2) byla rovněž spojena s vysokým tlakem v pravé síni (p = 0,016) a s plicní cévní rezistencí (p = 0,012). Kaplanova-Meierova analýza přežití prokázala, že dlouhodobé přežití je statisticky významně kratší u pacientů s CPI < 0,41. Závěr: Klidový CPI je u pacientů s pokročilým chronickým srdečním selháním spojen s úmrtím ze srdečních příčin.

Background: Hemodynamic parameters have recently emerged as tools for risk stratification of heart failure patients. Cardiac power output (CPO) is an indicator of cardiac performance. Cardiac power index (CPI) is calculated by indexing CPO to body surface area. The study aimed to demonstrate the prognostic role of resting CPI in advanced chronic heart failure patients. Methods: The study included patients with advanced chronic heart failure, ejection fraction below 30%, and classes III and IV functional capacity who had had right and left heart catheterization. A total of 99 patients were enrolled, with those having left ventricular assist device (LVAD) implantation or heart transplantation (HTx) excluded to determine LVAD- and HTx-free survival. Results: Of the 99 patients, 43 patients underwent LVAD and HTx surgery. Of the remaining 56 patients, 19 died (33.9%) over a period of 16 months (median). The value of CPI was associated with cardiac mortality (0.32 vs 0.42, p = 0.003). The cut-off level of CPI for mortality was 0.41 (89.5% sensitivity and 56.8% specificity). A diminished CPI (<0.41 W/m2) was also associated with high right atrial pressure (p = 0.016) and pulmonary vascular resistance (p = 0.012). A Kaplan-Meier survival analysis indicated that long-term survival was significantly reduced in patients with CPI <0.41. Conclusion: Cardiac power index at rest is associated with cardiac mortality in patients with advanced chronic heart failure.

• Klíčová slova
• index srdeční síly,
• MeSH
• Kaplanův-Meierův odhad MeSH
• kardiovaskulární fyziologické jevy * MeSH
• lidé MeSH
• míra přežití MeSH
• prognóza MeSH
• ROC křivka MeSH
• srdeční katetrizace MeSH
• srdeční selhání * mortalita   MeSH
• statistika jako téma MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• klinická studie MeSH

Heart failure (HF) has been declared as global pandemic and current therapies are still ineffective, especially in patients that develop concurrent cardio-renal syndrome. Considerable attention has been focused on the nitric oxide (NO)/soluble guanylyl cyclase (sGC)/cyclic guanosine monophosphate (cGMP) pathway. In the current study, we aimed to investigate the effectiveness of sGC stimulator (BAY41-8543) with the same mode of action as vericiguat, for the treatment of heart failure (HF) with cardio-renal syndrome. As a model, we chose heterozygous Ren-2 transgenic rats (TGR), with high-output heart failure, induced by aorto-caval fistula (ACF). The rats were subjected into three experimental protocols to evaluate short-term effects of the treatment, impact on blood pressure, and finally the long-term survival lasting 210 days. As control groups, we used hypertensive sham TGR and normotensive sham HanSD rats. We have shown that the sGC stimulator effectively increased the survival of rats with HF in comparison to untreated animals. After 60 days of sGC stimulator treatment, the survival was still 50% compared to 8% in the untreated rats. One-week treatment with sGC stimulator increased the excretion of cGMP in ACF TGR (109 ± 28 nnmol/12 h), but the ACE inhibitor decreased it (-63 ± 21 nnmol/12 h). Moreover, sGC stimulator caused a decrease in SBP, but this effect was only temporary (day 0: 117 ± 3; day 2: 108 ± 1; day 14: 124 ± 2 mmHg). These results support the concept that sGC stimulators might represent a valuable class of drugs to battle heart failure especially with cardio-renal syndrome, but further studies are necessary.

• MeSH
• guanosinmonofosfát cyklický metabolismus   MeSH
• guanylátcyklasa MeSH
• hypertenze * farmakoterapie   MeSH
• kardiorenální syndrom * MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• oxid dusnatý metabolismus   MeSH
• píštěle * MeSH
• potkani transgenní MeSH
• rozpustná guanylátcyklasa metabolismus   MeSH
• srdeční selhání * farmakoterapie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

INTRODUCTION: Heart failure (HF) is a serious complication of end-stage kidney disease (ESKD). However, most data come from retrospective studies that included patients on chronic hemodialysis at the time of its initiation. These patients are frequently overhydrated, which significantly influences the echocardiogram findings. The primary aim of this study was to analyze the prevalence of heart failure and its phenotypes. The secondary aims were (1) to describe the potential of N-terminal pro-brain natriuretic peptide (NTproBNP) for HF diagnosis in ESKD patients on hemodialysis, (2) to analyze the frequency of abnormal left ventricular geometry, and (3) to describe the differences between various HF phenotypes in this population. METHODS: We included all patients on chronic hemodialysis for at least 3 months from five hemodialysis units who were willing to participate, had no living kidney transplant donor, and had a life expectancy longer than 6 months at the time of inclusion. Detailed echocardiography together with hemodynamic calculations, dialysis arteriovenous fistula flow volume calculation, and basic lab analysis were performed in conditions of clinical stability. Excess of severe overhydration was excluded by clinical examination and by employing bioimpedance. RESULTS: A total of 214 patients aged 66.4 ± 14.6 years were included. HF was diagnosed in 57% of them. Among patients with HF, HF with preserved ejection fraction (HFpEF) was, by far, the most common phenotype and occurred in 35%, while HF with reduced ejection fraction (HFrEF) occurred only in 7%, HF with mildly reduced ejection fraction (HFmrEF) in 7%, and high-output HF in 9%. Patients with HFpEF differed from patients with no HF significantly in the following: they were older (62 ± 14 vs. 70 ± 14, p = 0.002) and had a higher left ventricular mass index [96(36) vs. 108(45), p = 0.015], higher left atrial index [33(12) vs. 44(16), p < 0.0001], and higher estimated central venous pressure [5(4) vs. 6(8), p = 0.004] and pulmonary artery systolic pressure [31(9) vs. 40(23), p = 0.006] but slightly lower tricuspid annular plane systolic excursion (TAPSE): 22 ± 5 vs. 24 ± 5, p = 0.04. NTproBNP had low sensitivity and specificity for diagnosing HF or HFpEF: with the use of the cutoff value of 8,296 ng/L, the sensitivity of HF diagnosis was only 52% while the specificity was 79%. However, NTproBNP levels were significantly related to echocardiographic variables, most significantly to the indexed left atrial volume (R = 0.56, p < 10-5) and to the estimated systolic pulmonary arterial pressure (R = 0.50, p < 10-5). CONCLUSIONS: HFpEF was by far the most common heart failure phenotype in patients on chronic hemodialysis and was followed by high-output HF. Patients suffering from HFpEF were older and had not only typical echocardiographic changes but also higher hydration that mirrored increased filling pressures of both ventricles than in those of patients without HF.

• Publikační typ
• časopisecké články MeSH

In atrial and ventricular tachyarrhythmias, reduced time for ventricular filling and loss of atrial contribution lead to a significant reduction in cardiac output, resulting in cardiogenic shock. This may also occur during catheter ablation in 11% of overall procedures and is associated with increased mortality. Managing cardiogenic shock and (supra) ventricular arrhythmias is particularly challenging. Inotropic support may exacerbate tachyarrhythmias or accelerate heart rate; antiarrhythmic drugs often come with negative inotropic effects, and electrical reconversions may risk worsening circulatory failure or even cardiac arrest. The drop in native cardiac output during an arrhythmic storm can be partly covered by the insertion of percutaneous mechanical circulatory support (MCS) devices guaranteeing end-organ perfusion. This provides physicians a time window of stability to investigate the underlying cause of arrhythmia and allow proper therapeutic interventions (e.g., percutaneous coronary intervention and catheter ablation). Temporary MCS can be used in the case of overt hemodynamic decompensation or as a "preemptive strategy" to avoid circulatory instability during interventional cardiology procedures in high-risk patients. Despite the increasing use of MCS in cardiogenic shock and during catheter ablation procedures, the recommendation level is still low, considering the lack of large observational studies and randomized clinical trials. Therefore, the evidence on the timing and the kinds of MCS devices has also scarcely been investigated. In the current review, we discuss the available evidence in the literature and gaps in knowledge on the use of MCS devices in the setting of ventricular arrhythmias and arrhythmic storms, including a specific focus on pathophysiology and related therapies.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Úvod: Nejčastější příčina úmrtí pacientů po transplantaci ledviny je kardiovaskulární onemocnění. Vysokoprůtočná arteriovenózní fistula (AVF) zvyšuje srdeční výdej a může se podílet na hyperkinetickém srdečním selhání. Sledování AVF u pacientů po transplantaci není zavedeno. Cílem naší práce bylo ve skupině pacientů po transplantaci ledviny s vysokoprůtočnou AVF provést redukci průtoku AVF ke snížení kardiálního zatížení. Metody: Byla provedena prospektivní studie u pacientů po transplantaci ledviny, kterým byl před transplantací založen cévní přístup k dialýze. AVF těchto pacientů byla vyšetřena ultrazvukem se zaměřením na průtok AVF a velikost arteria brachialis. V případě, že byla zjištěna vysokoprůtočná AVF, byla v indikované skupině pacientů provedena redukce průtoku. Výsledky: Bylo vyšetřeno 164 pacientů po transplantaci ledviny, z toho u 24 zjištěna hyperfunkční AVF. Celkem bylo provedeno 16 redukcí průtoku AVF, které vedly k průměrnému poklesu kardiálního indexu o 0,77 l/min/m2. Primární průchodnost rekonstrukcí byla 93,33 % po 12 měsících. U většiny pacientů došlo k subjektivnímu zmírnění dušnosti. Závěr: Redukce průtoku AVF vede ke zlepšení kvality života pacientů po transplantaci ledviny. Zachování funkční AVF je výhodné především u pacientů již opakovaně operovaných, kde jsou možnosti založení autologních AVF limitované.

Introduction: Cardiovascular disease is the most frequent cause of death in kidney transplant patients. High-flow arteriovenous fistula (AVF) increases cardiac output and may contribute to hyperkinetic heart failure. AVF follow-up is not implemented in kidney transplant patients. The aim of this study was to reduce AVF blood flow in a group of patients with a high-flow AVF following kidney transplantation to reduce cardiac strain. Methods: This prospective study was performed in kidney transplant patients who had a vascular access created before transplantation. The AVF of these patients was examined by ultrasound with a focus on AVF flow and brachial artery size. If high-flow AVF was detected, flow reduction was performed in the indicated group of patients. Results: The study examined 164 patients, of whom 24 had a hyperfunctional AVF (14.8%). A total of 16 AVF flow reductions were performed, which led to an average decrease in cardiac index by 0.77 L/min/m2. Primary patency of the reconstructions was 93.33% after 12 months. All patients experienced a subjective improvement in dyspnea. Conclusion: Reduction in AVF flow leads to an improvement in the quality of life of kidney transplant patients. Maintaining a functional AVF is beneficial, especially for patients after repeated surgeries, where the option of creating an autologous AVF is limited.

• MeSH
• arteriovenózní píštěl * chirurgie   diagnostické zobrazování   MeSH
• arteriovenózní zkrat škodlivé účinky   MeSH
• chronické selhání ledvin chirurgie   MeSH
• lidé MeSH
• prospektivní studie MeSH
• transplantace ledvin * MeSH
• Check Tag
• lidé MeSH

Detailed mechanism(s) of the beneficial effects of renal denervation (RDN) on the course of heart failure (HF) remain unclear. The study aimed to evaluate renal vascular responsiveness to angiotensin II (ANG II) and to characterize ANG II type 1 (AT1) and type 2 (AT2) receptors in the kidney of Ren-2 transgenic rats (TGR), a model of ANG II-dependent hypertension. HF was induced by volume overload using aorto-caval fistula (ACF). The studies were performed two weeks after RDN (three weeks after the creation of ACF), i.e., when non-denervated ACF TGR enter the decompensation phase of HF whereas those after RDN are still in the compensation phase. We found that ACF TGR showed lower renal blood flow (RBF) and its exaggerated response to intrarenal ANG II (8 ng); RDN further augmented this responsiveness. We found that all ANG II receptors in the kidney cortex were of the AT1 subtype. ANG II receptor binding characteristics in the renal cortex did not significantly differ between experimental groups, hence AT1 alterations are not responsible for renal vascular hyperresponsiveness to ANG II in ACF TGR, denervated or not. In conclusion, maintained renal AT1 receptor binding combined with elevated ANG II levels and renal vascular hyperresponsiveness to ANG II in ACF TGR influence renal hemodynamics and tubular reabsorption and lead to renal dysfunction in the high-output HF model. Since RDN did not attenuate the RBF decrease and enhanced renal vascular responsiveness to ANG II, the beneficial actions of RDN on HF-related mortality are probably not dominantly mediated by renal mechanism(s).

• Publikační typ
• časopisecké články MeSH

Chronic kidney disease is associated with increased cardiovascular morbidity and mortality. A well-functioning vascular access is associated with improved survival and among the available types of vascular access the arterio-venous (AV) fistula is the one associated with the best outcomes. However, AV access may affect heart function and, in some patients, could worsen the clinical status. This review article focuses on the specific cardiovascular hemodynamics of dialysis patients and how it is affected by the AV access; the effects of an excessive increase in AV access flow, leading to high-output heart failure; congestive heart failure in CKD patients and the contraindications to AV access; pulmonary hypertension. In severe heart failure, peritoneal dialysis (PD) might be the better choice for cardiac health, but if contraindicated suggestions for vascular access selection are provided based on the individual clinical presentation. Management of the AV access after kidney transplantation is also addressed, considering the cardiovascular benefit of AV access ligation compared to the advantage of having a functioning AVF as backup in case of allograft failure. In PD patients, who need to switch to hemodialysis, vascular access should be created timely. The influence of AV access in patients undergoing cardiac surgery for valvular or ischemic heart disease is also addressed. Cardiovascular implantable electronic devices are increasingly implanted in dialysis patients, but when doing so, the type and location of vascular access should be considered.

• MeSH
• arteriovenózní píštěl * MeSH
• arteriovenózní zkrat * škodlivé účinky   MeSH
• chronická renální insuficience * diagnóza   terapie   MeSH
• chronické selhání ledvin * MeSH
• dialýza ledvin MeSH
• lidé MeSH
• ligace MeSH
• transplantace ledvin * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

AIMS: Totally leadless cardiac resynchronization therapy (CRT) can be delivered with a combination of Micra and WiSE-CRT systems. We describe the technical feasibility and first insights into the safety and efficacy of this combination in European experience. METHODS AND RESULTS: Patients enrolled had indication for both Micra and WiSE-CRT systems because of heart failure related to high burden of pacing by a Micra necessitating system upgrade or inability to implant a conventional CRT system because of infectious or anatomical conditions. The endpoints of the study were technical success of WiSE-CRT implantation with right ventricle-synchonized CRT delivery, acute QRS duration reduction, and freedom from procedure-related major adverse events. All eight WiSE-CRT devices were able to detect the Micra pacing output and to be trained to deliver synchronous LV endocardial pacing. Acute QRS reduction following WiSE-CRT implantation was observed in all eight patients (mean QRS 204.38 ± 30.26 vs. 137.5 ± 24.75 mS, P = 0.012). Seven patients reached 6 months of follow-up. At 6 months after WiSE-CRT implantation, there was a significant increase in LV ejection fraction (28.43 ± 8.01% vs. 39.71 ± 11.89%; P = 0.018) but no evidence of LV reverse remodelling or improvement in New York Heart Association class. CONCLUSION: The Micra and the WiSE-CRT systems can successfully operate together to deliver total leadless CRT to a patient. Moreover, the WiSE-CRT system provides the only means to upgrade the large population of Micra patients to CRT capability without replacing the Micra. The range of application of this combination could broaden in the future with the upcoming developments of leadless cardiac pacing.

• MeSH
• kardiostimulátor * MeSH
• lidé MeSH
• prostředky srdeční resynchronizační terapie MeSH
• srdeční resynchronizační terapie * MeSH
• srdeční selhání * diagnóza   terapie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH