Cardiac resynchronization therapy is not commonly used in the early postoperative period in pati ents undergoing cardiac surgery who have left ventricular (LV) dysfunction and a history of heart failure. We performed a prospective randomized clinical trial to compare atrial synchronous right ventricular (DDD RV) and biventricular (DDD BIV) pacing within 72 hours after cardiac surgery in patients with an EF ≤ 35 %, a QRS interval longer than 120 msec and who had LV dyssynchrony detected by real-time three-dimensional echocardiography (RT3DE). Epicardial pacing was provided by a modified Medtronic INSYNC III pacemaker. An LV epicardial pacing lead was implanted on the latest activated segment of the LV based on RT3DE. The study included 18 patients with ischemic heart diseas e, with or without valvular heart disease (14 men, 4 women, average age 71 years). Patients undergoing DDD BIV pacing had a statistically significant greater CO and CI (CO 6.7±1.8 l/min, CI 3.4±0.7 l/min/m²) than patients undergoing DDD RV pacing (CO 5.5±1.4 l/min, CI 2.8±0.7 l/min/m²), p<0.001. DDD BIV paci ng in the early postoperative period after cardiac surgery corrects LV dyssynchrony and has better hemodynamic results than DDD RV pacing., F. Straka ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
This study investigated whether each part of the heart is evenly innervated by the left or right vagus and observed the mechanism of compensatory recovery after unilateral cervical vagotomy. HR, BP, LVSP and ±dp/dt max all decreased one week after left vagotomy, whereas only BP and -dp/dt max decreased one week after right vagotomy. We stern blot analyses revealed that the expression of M2 receptors in the left atrium and left ventricle was upregulated after subacute (1 week) left/right vagotomy. However, significantly more cholinesterase-positive nerves in LV and RV were seen one week after unilateral vagotomy compared to the sham-operated group. In addition, baroreflex sensitivity was increased after subacute right vagotomy. The decreasing effects of ACh (0.5 μ g/kg) on LVSP and ±dp/dt max (but not on HR and BP) were facilitated by subacute unilateral vagotomy. Our present experiments indicate that 1) the working myocardium is innervated bilaterally by the vagus, 2) ventricular contractility is influenced more by denervation of the left than the right vagus and 3) up-regulation of M2 muscarinic receptors in the left heart, increase of cholinergic nerves, and high baroreflex sensitivity could be involved in the mechanism of compensatory hemodynamic recovery via contralateral vagus overactivity, thereby amplifying contralateral vagal activity and decreasing cardiac contractility., L. N. Chen, W. J. Zang, X. J. Yu, J. Liu, D. L. Li, S. S. Kong, J. Lu, X. L. Xu., and Obsahuje bibliografii a bibliografické odkazy
The aims were to explore the effect of head-up tilt (HUT) to 30 and 60 degrees on hemodynamics and tissue oxygenation in anesthetized healthy swine. The data serve as a reference for a study of resuscitation efficacy at HUT such as during transport. Nine healthy swine (49±4 kg) were anesthetized and multiple sensors including myocardial pressure-volume loops catheter, carotid flow probe, blood pressure catheters, near infrared spectroscopy (NIRS) tissue oximetry and mixed venous oximetry (SVO2) catheter were introduced and parameters continuously recorded. Experimental protocol consisted of baseline in supine position (15 min), 30 degrees HUT (15 min), recovery at supine position (15 min) and 60 degrees HUT (5 min). Vacuum mattress was used for body fixation during tilts. We found that 30 and 60 degrees inclination led to significant immediate reduction in hemodynamic and oximetry parameters. Mean arterial pressure (mm Hg) decreased from 98 at baseline to 53 and 39, respectively. Carotid blood flow dropped to 47 % and 22 % of baseline values, end diastolic volume to 49 % and 53 % and stroke volume to 47 % and 45 % of baseline. SVO2 and tissue oximetry decreased by 17 and 21 percentage points. The values are means. In conclusions, within minutes, both 30 and 60 degrees head-up tilting is poorly tolerated in anesthetized swine. Significant differences among individual animals exist., M. Mlcek, J. Belohlavek, M. Huptych, T. Boucek, T. Belza, S. Lacko, P. Krupickova, M. Hrachovina, M. Popkova, P. Neuzil, O. Kittnar., and Obsahuje bibliografii
Operations in the pleural cavity are connected with circulatory changes in pulmonary circulation and general changes of hemodynamics. These changes are influenced by the position of patient’s body on the operation table and by the introduction of artificial pneumothorax. Thoracoscopy is an advanced surgical approach in thoracic surgery, but its hemodynamic effect is still not known. The aim of the present study was to compare the hemodynamic response to surgeries carried out by open (thoracotomy - TT) and closed (thoracoscopy - TS) surgical approach. Thirty-eight patients have been monitored throughout the operation - from the introduction of anesthesia to completing the surgery. Monitored parameters were systolic blood pressure (BPs), diastolic blood pressure (BPd), O2 saturation (SaO2), systolic blood pressure in pulmonary artery (BPPAs), diastolic blood pressure in pulmonary artery (BPPAd), wedge pressure (PW), central venous pressure in right atrium (CVP), cardiac output (CO) and total peripheral resistance (TPR). No significant difference has been found in hemodynamic response between TT and TS groups. Significant changes of hemodynamic parameters occurring during the whole surgical procedure were detected in both technical approaches. The most prominent changes were found after the position of patients was changed to the hip position (significantly decreased BPs, BPd, MAP, SaO2 and BPPAs) and 5 min after the pneumothorax was established (restoration of the cardiac output to the initial value and significant decrease of the TPR). It can be concluded that the thoracoscopy causes almost identical hemodynamic changes like the thoracotomy., S. Trča ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
In experimental and human diabetes mellitus, evidence for an impaired function of the vascular endothelium has been found and has been suggested to contribute to the development of vascular complications in this disease. The aim of the study was to evaluate possible regional hemodynamic in vivo differences between healthy and diabetic rats which would involve nitric oxide (NO). Central hemodynamics and regional blood flow (RBF) were studied using radioactive microspheres in early streptozotocin (STZ)-diabetic rats and compared to findings in healthy control animals. This method provides a possibility to study the total blood flow and vascular resistance (VR) in several different organs simultaneously. L-NAME iv induced widespread vasoconstriction to a similar extent in both groups. In the masseter muscle of both groups, acetylcholine 2 μg/kg per min, induced a RBF increase, which was abolished by pretreatment with L-NAME, suggesting NO as a mediator of vasodilation. In the heart muscle of both groups, acetylcholine alone was without effect while the combined infusion of acetylcholine and L-arginine induced an L-NAME-sensitive increase in RBF. The vasodilation induced by high-dose acetylcholine (10 μg/kg per min) in the kidney was more pronounced in the STZ-diabetic rats. The results indicate no reduction in basal vasodilating NO-tone in the circulation of early diabetic rats. The sensitivity to vasodilating effects of acetylcholine at the level of small resistance arterioles vary between tissues but was not impaired in the diabetic rats. In the heart muscle the availability of L-arginine was found to limit the vasodilatory effect of acetylcholine in both healthy and diabetic rats. In conclusion, the results indicate a normal action of NO in the investigated tissues of the early STZ-diabetic rat., E. Granstam, S.-O. Granstam., and Obsahuje bibliografii
Pulmonary hypertension (PH) unresponsive to pharmacological intervention is considered a contraindication for orthotopic heart transplantation (OHTX) due to risk of postoperative right-heart failure. In this prospective study, we describe our experience with a treatment strategy of improving severe PH in heart transplant candidates by means of ventricular assist device (VAD) implantation and subs equent OHTX. In 11 heart transplantation candidates with severe PH unresponsive to pharmacological intervention we implanted VAD with the aim of achieving PH to values acceptable for OHTX. In all patients we observed significant drop in pulmonary pr essures, PVR and TPG (p<0.001 for all) 3 months after VAD implantation to values sufficient to allow OHTX. Seven patients underwent transplantation (mean duration of support 216 days) while none of patients suffered right-side heart failure in postoperative period. Two patients died after transplantation and five patients are living in very good condition with a mean duration of 286 days after OHTX. In our opinion, severe PH is not a contraindication for orthotopic heart transplantation any more., J. Kettner ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Cíl: Na kohortě pacientů s asymptomatickou stenózou vnitřní karotidy podstupujících karotickou endarterektomii otestovat protokol vyšetření hemodynamiky mozku pomocí magnetické rezonance a zjišťovat rozdíl v kognitivní kondici pomocí neuropsychologické testové baterie RBANS (Repeatable Battery for the Assessment of Neuropsychological Status). Metody: Standardní karotická endarterektomie pro asymptomatickou stenózu vnitřní karotidy v intravenózní celkové anestezii se selektivním užitím shuntu. Měření průtoku velkými cévami Willisova okruhu pomocí magnetickorezonační angiografie s fázovým kontrastem před operací a tři měsíce po operaci, a to paralelně s psychologickým vyšetřením testovou baterií RBANS. Výsledky: U pěti žen a 12 mužů s nekomplikovanou karotickou endarterektomií pro asymptomatickou stenózu vnitřní karotidy bylo zaznamenáno signifikantní zlepšení v oblasti kognitivního výkonu v celkovém skóru neuropsychologické baterie (p = 0,05) a indexech týkajících se bezprostřední paměti (p = 0,04) a řeči (p = 0,01). Následné korelace lokální změny hemodynamiky a změn v kognitivním výkonu z magnetickorezonančních dat získaných od 12 pacientů byly signifikantní pro přední mozkovou tepnu a index bezprostřední paměti (p = 0,01), a pro střední mozkovou tepnu a indexy řeči (p = 0,02) a vizuoprostorové orientace (p = 0,02). Závěr: V pilotní studii byl na malé skupině pacientů s klinicky i radiologicky asymptomatickou stenózou vnitřní karotidy poprvé v naší literatuře otestován protokol vyšetření průtoku krve (ml/min) na všech velkých cévách Willisova okruhu a srovnány změny hemodynamiky před karotickou endarterektomií a tři měsíce po ní. V úrovni kognitivního výkonu bylo prokázáno zlepšení, u kterého byl v dílčích testech neuropsychologické baterie RBANS identifikován vztah s hodnotami průtoků v povodí přední nebo střední mozkové tepny. Větší studie s delším sledováním výsledků je proveditelná., Aim: To test a brain haemodynamics examination protocol using magnetic resonance imaging and to investigate the differences in cognitive performance with a neuropsychology test battery RBANS (Repeatable Battery for the Assessment of Neuropsychological Status) on a cohort of patients with an asymptomatic carotid stenosis undergoing carotid endarterectomy. Methods: Standard carotid endarterectomy in asymptomatic carotid stenosis under general intravenous anaestehesia with selective use of a shunt. Flow measurement in major vessels of the Willis circle using magnetic resonance angiography with phase contrast before and three months after the operation and concurrently with RBANS psychological examination testing battery. Results: Significant cognitive performance improvement in neuropsychological test battery total score and in short-term memory (p = 0.04) and speech (p = 0.01) indexes was seen in five women and 12 men undergoing uncomplicated carotid endarterectomy. Subsequent correlations of local haemodynamic change and cognitive performance change in 12 patients were significant for the anterior cerebral artery and immediate memory index (p = 0.01), and for the medial cerebral artery and speech indeces (p = 0.02) and visuospatial orientation (p = 0.02). Conclusion: In a pilot study, a flow (ml/min) examination protocol of all major Willis circle arteries was tested and haemodynamic changes before the operation and in three months follow-up after carotid endarterectomy were compared on a small group of patients with radiologically and clinically asymptomatic carotid stenosis for the first time in Czech literature. Improvement in cognitive performance was demonstrated and an association with anterior or medial cerebral artery flow values was identified in individual RBANS tests. A larger study with a longer follow-up is feasible. Key words: carotid artery atherosclerosis – carotid artery stenosis – carotid endarterectomy – cognition – neuropsychology The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers., and J. Fiedler, T. Mrhálek, M. Vavrečka, S. Ostrý, M. Bombic, J. Kubále, V. Přibáň, M. Preiss, I. Stuchlíková
Hypertenze závislá na soli patří mezi nejčastější rizikové faktory kardiovaskulárních onemocnění. U většiny případů je příčina tohoto onemocnění neznámá, avšak významný podíl hypertenzních jedinců citlivých k soli má zvýšené hladiny mineralokortikoidů. V tomto přehledném článku popisujeme hemodynamické abnormality a mechanismy odpovědné za vývin této formy hypertenze., Salt-dependent hypertension is a leading cause of cardiovascular diseases. In most cases, the etiology is unknown, but it has been estimated that a significant percentage of salt-sensitive hypertensive individuals have mineralocorticoid excess. In this review, we describe hemodynamic abnormalities and mechanisms responsible for initiation of this form of hypertension., and Michal Pravenec.
Penetrující srdeční poranění je zatíženo vysokým rizikem úmrtí. Incidence poranění je v evropských zemích nízká (0,1 % všech přijatých traumat), bohužel 80–94 % nemocných v jejich důsledku zemře dříve, než se jim dostane adekvátního ošetření, a to z důvodu srdeční tamponády nebo exsanguinace. V souvislosti s anatomickým uložením srdce je nejčastěji poraněna pravá komora srdeční následovaná komorou levou, pravou síní a poraněním odstupujících velkých cév. Souběžné poranění koronárních tepen je udáváno mezi 3 a 9 % případů. Pro přežití nemocných je zásadní jejich rychlé zajištění na místě nehody, monitorovaný transport a neodkladné provedení chirurgického ošetření. Průkaz perikardiální efuze (> 5 mm) pomocí echokardiografie nebo CT angiografie u penetrujícího hrudního traumatu je indikací k chirurgické revizi. Hemodynamická nestabilita, asystolie nebo elektromechanická disociace jsou nezávislými prediktory úmrtí nemocných, rovněž časové zpoždění mezi vznikem poranění a definitivním ošetřením přímo koreluje s prognózou nemocných. V souborech operovaných kardiochirurgickými pracovišti je udáváno 80–100% přežití nemocných s jejich následnou plnohodnotnou integrací do normálního života., Penetrating cardiac injury remains a highly lethal form of trauma today. Although the incidence in European countries is low (approximately 0.1% of all hospital‑admitted traumas), the mortality rate ranges between 80 and 94% due to cardiac tamponade or exsanguination. Due to the anatomic position of the heart, right ventricle injury dominates, followed by injury of the left ventricle, right atrium, and great vessels. Concomitant coronary artery injury is present in 3–9% of all cases. The only meaningful treatment is a scoop‑and‑run approach and emergency operative intervention. Pericardial effusion (> 5mm) confirmed by sonography or CT‑angiography in a thoracic penetrating trauma is an indication for surgical intervention. Hemodynamic instability, cardiac arrest, electromagnetic dissociation and prolonged injury‑to‑gate time represent independent risk factors for death. However, the survival rate of patients revised by a cardiothoracic surgeon ranges from 80% to 100%, with a high chance of returning back to normal life., and Konečný J., Šimek M., Klváček A., Hájek R., Škorpil J., Hubáček P., Lonský V.
Early recognition of collapsing hemodynamics in pulmonary embolism is necessary to avoid cardiac arrest using aggressive medical therapy or mechanical cardiac support. The aim of the study was to identify the maximal acute hemodynamic compensatory steady state. Overall, 40 dynamic obstructions of pulmonary artery were performe d and hemodynamic data were collected. Occlusion of only left or right pulmonary artery did not lead to the hemodynamic collapse. When gradually obstructing the bifurcation, the right ventri cle end-diastolic area expanded proportionally to pulmonary artery mean pressure from 11.6 (10.1, 14.1) to 17.8 (16.1, 18.8) cm 2 (p<0.0001) and pulmonary artery mean pressure increased from 22 (20, 24) to 44 (41, 47) mmHg (p<0.0001) at the poin t of maximal hemodynamic compensatory steady state. Sim ilarly, mean arte rial pressure decreased from 96 (87, 101) to 60 (53, 78) mmHg (p<0.0001), central venous pressure increased from 4 (4, 5) to 7 (6, 8) mmHg (p<0.0001), heart rate increased from 92 (88, 97) to 147 (122, 165) /min (p<0.0001), contin uous cardiac output dropped from 5.2 (4.7, 5.8) to 4.3 (3.7, 5.0) l/min (p=0.0023), modified shock index increased from 0.99 (0.81, 1.10) to 2.31 (1.99, 2.72), p<0.0001. In conclusion, in stead of continuous cardiac output all of the analyzed parameters can sensitively determine the individual maximal compensatory response to obstructive shock. We assume their monitoring can be used to predict the critical phase of the hemodynamic status in routine practice., J. Kudlička ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy