PubMed Health⌕ Search

Biomedical subjects

A Brezina

Publications and source records attributed to A Brezina.

At least 19 recordsLinked to original sources
PubMed2006

[Methylene blue in the therapy of vasoplegic syndrome after cardiac surgery procedure].

Vasoplegic syndrome after cardiac surgery with cardiopulmonary bypass is severe complication with high morbidity and mortality. Without appropriate therapy the syndrome advances to the shock state with subsequent multiorgan failure. Basic haemodynamic parameters of vasoplegic syndrome include low systemic vascular resistance with severe hypotension, tachycardia, and normal or increased cardiac output and low filling pressures. In therapy norepinephrine and vasopressin or its analogues are used. Methylene blue is other therapeutic option. The case of successful application of methylene blue for the treatment of vasoplegic syndrome is presented.

Aged↗
PubMed2005

[Mechanical cardiac support--the first use in Czech Republic].

BACKGROUND: Implantation of mechanical assist device is widely accepted modality of treatment of patients with refractory heart failure. In the present study we evaluated our first one-year experiences with this method for bridging patients to cardiac transplantation. METHODS AND RESULTS: Between April 2003 and May 2004, the Thoratec VAD (Thoratec, Pleasanton, CA, USA) was implanted in 6 patients ( males; age 28-61 years) as a bridge-to-transplant procedure after having received maximum inotropic support and who were at imminent risk of death. In all patients was performed VAD as biventricular device (BiVAD). During a week after placement was observed recovery of organs function in all patients. Five patients survived to heart transplantation. One patient died 21 days after BiVAD placement due to massive bleeding to the respiratory tract. In post-transplantation period 1 patient died second day from acute graft failure and other patient died 34 days after from intracranial bleeding. Three patients has been discharged from the hospital and they are surviving more than I year. CONCLUSIONS: Analysis of our first experiences with the Thoratec BiVAD implantation as bridging to heart transplantation suggests that it is well suited method with respect to long- term prognosis of this group of patients.

Adult↗
PubMed1998

[Modern cardiac anesthesia].

Contemporary cardioanaesthesia is based on the use of opioid effects, whereby their dosage is steadily decreased. This calls for supplementation of anaesthesia by further pharmacological preparations which ensure adequate anaesthesia. Despite great efforts, neither, substances available at present nor their combinations are sufficient to suppress surgical stress completely. The authors attempt therefore selective influencing of the sympathetic nerve. In this respect preparations which stimulate sympathetic alpha2 receptors seem promising. The general trend of contemporary cardioanaesthesia is an effort to reduce the time spent by patients in the intensive care unit to a minimum. The motivation are in the first place economic reasons.

Anesthesia↗
PubMed1994

[Magnetic resonance tomography (MRT) of the breast in problem patients].

Over the past few years MRI has become important in the evaluation of inconclusive mammograms. These studies were performed on high-field strength machines, which have the disadvantage of limited accessibility. We evaluated 185 investigations on 169 patients on a 0.5 Tesla MR machine using a dynamic sequence and gadolinium (Gd) DTPA. The results in 107 patients were correlated with the histological findings and MRI assessment proved correct in 44 of 47 benign lesions (93.6%) and 57 of 60 malignant lesions (95%). The 3 false positive results occurred in patients with mastitis, fibroadenoma and an ectatic vessel, respectively. Of the 3 false negative results 2 occurred in patients with microcarcinomas and were due to partial-volume artefacts, whilst the third was due to a technical error. These results compare with those reported in the literature using mainly high-field strength machines. Furthermore, unsuspected second tumours were diagnosed in the ipsilateral breast of 6 women and infiltration of the adjacent thoracic wall in 4 women, findings which had not been evident on mammography. Hence, our results indicate that a mild-field strength MR machine is a valuable tool not only for the non-invasive differentiation between benign and malignant lesions of the breast, but also for planning therapeutic strategy.

Adult↗
PubMed1994

[Special features of anesthesia during surgery for acquired heart valve defects].

The authors describe some special features as regards anesthesia with large opioid doses in patients operated on account of acquired valvular disease. They emphasize in particular the importance of adequate knowledge of pathophysiological changes associated with the damage of different orifices and their interpretation in the anaesthesiological procedure which is the basis of its success. In the conclusion the authors describe basic haemodynamic changes in combined simultaneous affection of several valves.

Anesthesia↗
PubMed1993

[Hemodynamic effects of enoximone in patients with low left ventricular ejection fraction in surgery for ischemic heart disease].

Acute heart failure following cardiac surgery in extracorporeal circulation (EC) still poses a formidable problem requiring intensive pharmacological therapy and, often, also mechanical support. Preoperatively reduced left ventricular (LV) function raises the risk for the development of this complication. In their pilot study, the authors evaluated the haemodynamic effects of enoximone, a selective phosphodiesterase III inhibitor, administered at a dose of 1 mg/kg b.w. to 15 patients with a preoperative LV ejection fraction < or = 35% 15 minutes before weaning from EC after an elective myocardial revascularization procedure. All patients were weaned from EC at first attempt without any problems and left the operating theatre in good condition. Enoximone administration led, in the monitored period (45 minutes after administration), to statistically significant increases in cardiac index (+68%; p < 0.01), oxygen supply (+75%; p < 0.01) and oxygen saturation in mixed venous blood (+10%; p < 0.1) and statistically significant decreases in pulmonary and systemic vascular resistance indexes (-52% and -48%, respectively; p < 0.001) and in oxygen extraction (-31%; p < 0.001). These changes were associated with decreases in central venous, mean pulmonary artery, and pulmonary capillary wedge pressure (n.s.). No serious side effects were seen, and the authors conclude enoximone can be the drug of first choice in high-risk patients following heart surgery in EC and requiring inotropic support.

Adult↗
PubMed1993

Cardioprotective action of sodium gamma-hydroxybutyrate against isoproterenol induced myocardial damage.

In this study, the effects of graded doses of isoproterenol (IP) on the heart were examined in untreated gerbils and in gerbils anaesthetized with gamma-hydroxybutyrate (GHB), an endogenous metabolite with energy sparing properties. We were interested in the cardioprotective potential of GHB. IP was administered intraperitoneally in doses of 0.1, 0.3. 2.5 and 10.0 mg/kg to different groups of gerbils. Half the gerbils in each treatment group received 500 mg/kg of GHB 30 min before IP, and 250 mg/kg at three subsequent 2-hour intervals. The remaining gerbils in each treatment group received saline at these time points. The animals were sacrificed after 8 hours. The accumulation of neutral fat droplets in the sarcoplasm was the most consistent effect of IP. The highest dose also produced some scattered myofibre death. The accumulation of fat in the cells could be estimated semi-quantitatively using a histochemical reaction for succinic dehydrogenase, and the volume of fat could be measured more accurately by electron microscopic morphometry. These measurements showed that IP produced a three to five-fold increase in sarcoplasmic fat volume. GHB either abolished or significantly reduced the accumulation of fat and it also completely prevented the myofibre death caused by the highest doses of IP. This cardioprotective effect of GHB was independent of its hypothermic action. Based on this experience, ultrastructural morphometry of sarcoplasmic fat appears to be a promising method for evaluating cardioprotective measures.

Animals↗
PubMed1993

Effects of high plasma epinephrine and Ca2+ concentrations on neonatal myocardial function after ischemia.

Administration of catecholamines to newborn infants may potentiate reperfusion injury because of increased transsarcolemmal Ca2+ influx and the presence of less developed sarcoplasmic reticulum in the immature hearts. We investigated the effect of administration of epinephrine (1.5 micrograms/kg per minute for 120 minutes) before ischemia and modified serum ionized Ca2+ concentrations in the cardioplegic solution and perfusate on postischemic left ventricular systolic and diastolic function in 25 piglets (5 to 7 days old) undergoing 90 minutes of cold blood cardioplegic arrest. The piglets were divided into four groups; Ca2+ 1.2 mmol/L, group A (n = 6), Ca2+ 0.25 mmol/L, group B (n = 6), Ca2+ 1.2 mmol/L and epinephrine, group C (n = 6), Ca2+ 0.25 mmol/L and epinephrine, group D (n = 7). Left ventricular function was assessed by a conductance catheter in the left ventricle measuring end-systolic and end-diastolic pressure-volume relationships during transient vena caval occlusion. By analysis of covariance, only Ca2+ concentration was important in predicting ventricular function recovery after ischemia (p < 0.01). End-systolic elastance decreased in all groups after ischemia; the magnitude was significantly greater in the normal groups (51% versus 35%, p < 0.01). There was a significant increase in the chamber stiffness index after administration of epinephrine before ischemia (p < 0.05). Groups with low Ca2+ perfusate (B and D) had no change in chamber stiffness index after ischemia. In contrast, there was a significant increase in chamber stiffness in the normal Ca2+ groups with (C) or without (A) epinephrine after ischemia (p < 0.05). Adenosine triphosphate stores declined significantly in the normal Ca2+ groups--48% versus 18% in the low Ca2+ groups (p < 0.01). We conclude that low Ca2+ concentrations in the perfusate and cardioplegic solutions better preserve left ventricular function in the normal and in epinephrine-stressed neonatal heart after ischemia.

Adenosine Triphosphate↗
PubMed1993

The protective effect of magnesium on acute catecholamine cardiotoxicity in the neonate.

Neonates undergoing heart surgery are exposed to high levels of circulating catecholamines. Our objective was to determine to what extent administration of magnesium counters epinephrine-induced cardiotoxicity. We assessed left ventricular function (pressure-volume data obtained by the conductance catheter/micromanometer technique) and ultrastructure in newborn pigs 3 to 5 days of age before and after administration of epinephrine alone (2 micrograms/kg/min, group A, n = 6) and simultaneously with magnesium sulfate (8 mmol/L, 5 ml/hr, group B, n = 6). Plasma levels of magnesium were maintained at 200% to 250% of control, and ionized calcium was maintained at normal levels. During administration of epinephrine, there was a significant increase in end-systolic elastance from 8.9 +/- 2 to 15 +/- 3 mm Hg/ml in group A and from 7.8 +/- 2 to 16 +/- 3 mm Hg/ml in group B (p < 0.05). This increase was accompanied by an increase in chamber stiffness index (p < 0.05) and shortening of the time constant of isovolumic relaxation (p < 0.05; group A, 19 +/- 3 to 13 +/- 3 msec; Group B, 20 +/- 2 to 15 +/- 2 msec). After epinephrine was discontinued, however, systolic and diastolic indexes returned to baseline levels in group B, whereas group A exhibited a significant reduction in end-systolic elastance (5 +/- 1 mm Hg/ml; p < 0.05) and an increase in chamber stiffness index (0.7 +/- 0.08 versus 0.4 +/- 0.1 ml-1; p < 0.05) and time constant (25 +/- 1 versus 19 +/- 3 msec). Left ventricular dysfunction in group A was associated with focal sarcolemmal rupture and mitochondrial swelling, whereas only minor reversible changes (microvesicular lipid accumulation) were seen in group B. We conclude that magnesium has a protective effect against epinephrine-induced cardiotoxicity because of its blocking action on calcium influx of ionized calcium and could be of therapeutic benefit in the perioperative period.

Adenosine Triphosphate↗
PubMed1992

[Coronary surgery at the Institute of Clinical and Experimental Medicine].

In 1971-1991 in the Institute of Clinical and Experimental Medicine 2386 operations on account of IHD were performed. 2154 aortocoronary bypasses, 6 Vineberg operations, 51 valvular prostheses and aortocoronary bypasses, 128 resections of left ventricular aneurysms and 47 closures of post-infarction perforations of the interventricular septum. The mortality from aortocoronary bypasses during the entire period was 6.9%. The authors discuss different periods, changes of the operative technique and contemporary views on surgical treatment of IHD.

Cardiac Surgical Procedures↗
PubMed1992

[Anesthesia using high doses of fentanyl in cardiac surgery].

The authors describe their own experience with anaesthesia using large doses of fentanyl in patients operated on account of ischaemic heart disease and acquired valvular defects. Considerable stability of the circulation and careful monitoring of cardiorespiratory parameters along with aimed influencing of serious deviations is the basis of success of this procedure, which makes it possible to perform cardiosurgery in high risk patients. The authors try to improve the described method further by using some modern procedures.

Anesthesia↗
PubMed1991

[Selection of correct treatment in patients with low cardiac output after open-heart surgery].

In operations of the open heart inadequate cardiac output can lead to the so-called syndrome of a low cardiac output. The main indicator of cardiac function is the cardiac index. In patients in a critical state reduction of the cardiac index below 1.9 l/min q.m. suggests the presence of this syndrome. The submitted paper deals with the early detection of a low cardiac output which makes it possible to select optimal treatment before clinical signs of failure as well as further complications develop. The submitted paper deals with a group of 115 operated patients incl. 53 operated on account of IHD and 62 on account of rheumatic heart disease. Treatment was according to haemodynamic values divided into four groups: 1. Insurance of an optimal intravascular volume without pharmacological support, 2. pharmacological support of vasodilatating agents (nitroglycerine, sodium nitroprusside), 3. positive inotropic support by dobutamine, 4. support by a combination of vasodilatating agents and positive inotropic pharmaceutical preparations (dobutamine, dopamine). The favourable effect of treatment in the above groups is apparent already after four hours, and after 20 hours the investigated values shift to an optimal zone. The authors emphasize the high diagnostic value of comprehensive extensive monitoring which influences and controls therapy by retrospective informations.

Cardiac Output, Low↗
PubMed1991

Age-related response to epinephrine-induced myocardial stress. A functional and ultrastructural study.

Left ventricular systolic and diastolic function before, during, and after a 2-hour intravenous infusion of epinephrine at either 0.5 micrograms/kg/min or 2 micrograms/kg/min were assessed by pressure-volume data obtained by conductance catheter micromanometer technique and correlated with cardiac ultrastructure and plasma levels of epinephrine in neonatal (3-5 days old, n = 12) versus adult (3-4 months old, n = 11) pigs. Administration of epinephrine at 0.5 micrograms/kg/min resulted in an increase in end-systolic elastance (Ees) only in adults, whereas at 2.0 micrograms/kg/min Ees increased in both groups. After 2-hour administration of epinephrine at 2.0 micrograms/kg/min, Ees decreased significantly (p less than 0.05) from the preinfusion baseline value of 8.9 +/- 2 (mean +/- SD) to 5 +/- 1.7 mm Hg/ml, and a significant (p less than 0.05) increase in left ventricular volume elasticity (VdP/dV) from 0.4 +/- 0.02 to 1.4 +/- 0.2 mm Hg occurred in neonates versus no change from baseline in either Ees or VdP/dV in the adults. These changes in the neonates were associated with sarcolemmal rupture and mitochondrial Ca2+ granule deposition versus normal cardiac ultrastructure in the adults. We conclude that the neonatal myocardium is more susceptible to cardiotoxicity from circulating epinephrine.

Aging↗
PubMed1989

Quantitative evaluation of myocardial injury induced by acute cerebral ischaemia and its prevention by beta 1-adrenergic blockade. An ultrastructural morphometry study.

The protective effects of beta 1-adrenergic blockade with metoprolol (Betaloc Astra) were demonstrated in the gerbil model of myocardial injury provoked by acute ischaemic brain lesions. The myocardial injury was reversible and lipid droplet accumulation was its most striking morphological feature. These droplets were easy to measure in EM photographs and their size was expressed as percentage of sarcoplasmic volume. The EM data of fat accumulation were compared in hearts of carotid-ligated animals with and without metoprolol pretreatment, and in animals with the carotid isolated only, at standard intervals 3-48 h after operation. While in carotid-ligated-only animals the average myocardial fat contents rose to a peak of 1.9% at 10 h, in metoprolol pretreated animals the amount of fat was always significantly lower and started to return earlier to basal values (peak at 6 h, 1.1%). In carotid-isolated-only animals, fat accumulation peaked at 6-10 h (1.1%) and returned quickly to normal levels (0.34 +/- 0.18%). This effective pharmacological blockade with metoprolol strongly supports the concept of catecholamine mediation between acute intracranial lesions and myocardial injury. The background and significance of myocardial fat accumulation is discussed. The EM morphometry of fat droplets appears to be a suitable tool for quantification of reversible myocardial damage most useful for experimental evaluation of cardioprotective measures. As changes in succinic dehydrogenase histochemistry (from 'myofibrillar' to 'granular' pattern) correlated with EM measured fat accumulation, the simplicity and speed of the SDH method recommends itself for fast orientation about presence of myocardial damage.

Acute Disease↗
PubMed1988

Reversible myocardial damage in gerbil brain ischaemia and its prevention by beta-adrenergic blockade.

Acute cerebral infarction in gerbils, produced by unilateral carotid ligation, was used as a model to investigate secondary myocardial changes. The extent of the myocardial damage revealed by succinic dehydrogenase (SDH) histochemistry and by release of myocardial creatine phosphokinase (MB-CK) was measured in gerbils sacrificed from 3 to 48 h after either carotid ligation, carotid isolation only or skin incision only. For technical reasons dead animals were excluded from analysis. Of surviving ligated animals 74% developed neurological deficits related to brain ischaemia. A significant weight increase in the ipsilateral hemisphere was found at 6-10 h, and maximal histological damage at 16 h, both partially reversible thereafter. Non-ligated animals did not develop neurological changes, and showed neither brain swelling nor cerebral histopathology. Extensive cardiac damage was shown by the SDH method from 3 h postoperatively, and confirmed by the elevated serum levels of MB-CK in the carotid-ligated group. The SDH changes were identical with those described in the hearts of patients with acute intracranial lesions, and appeared to be reversible. The effect of beta-adrenergic blockade was assessed in this model. Metoprolol tartrate injected intraperitoneally 3 h before and 1 h after carotid ligation (10 mg/kg each dose) significantly decreased the extent of myocardial damage as estimated both with SDH histochemistry and MB-CK serum levels. It had no effect on the ischaemic brain changes. These results strongly support the concept of catecholamine mediation of myocardial injury resulting from acute brain lesions.

Animals↗
PubMed1986

High persistence rate of established coronary artery lesions secondary to Kawasaki disease among a panethnic Canadian population.

The incidence of resolution of proximal coronary artery lesions subsequent to Kawasaki disease over an 11-year period was studied retrospectively. In 28 patients proximal coronary artery lesions were identified by two-dimensional echocardiography or angiography at 1 to 3 months after disease onset. Follow-up data were adequate in 27 patients, 17 of whom were boys; 18 were white, two black, four Oriental (non-Japanese), and three of East Indian origin. Age at onset of Kawasaki disease ranged from 11 weeks to 9 years (mean 2.5 years). Coronary artery lesions were categorized as ectatic (internal diameter greater than 3 mm in those less than 5 years of age) or aneurysmal (internal lumen of a segment one and one-half times larger than an adjacent segment). Resolution was assessed by two-dimensional echocardiography or angiography during a follow-up period of 3 months to 11 years (mean 2.7 years). Apparent resolution (vessel diameter less than 3 mm) of coronary artery lesions occurred in four (15%) patients--one with aneurysmal lesions, three with ectatic lesions--all within 1 year of disease onset. Eight patients developed myocardial infarction; one of these patients died. The resolution rate was less than previously reported. This high rate would warrant closer attention to the state and sequelae of coronary artery lesions, including obstructive coronary artery disease, in follow-up assessments.

Aneurysm↗
PubMedDate not supplied

Cardioprotective effects of sodium gamma-hydroxybutyrate (GHB) on brain induced myocardial injury.

Gamma-hydroxybutyrate (GHB) was evaluated as a protective agent in a gerbil model of non-lethal myocardial injury that follows brain ischaemia. The accumulation of fat droplets in myocardial fibers following brain infarction was measured by electron microscopic morphometry and expressed as a percentage of the area of the sarcoplasm. GHB treatment significantly reduced the area occupied by lipid droplets compared with that found in saline treated controls measured both 10 hours (p less than .005) and 24 hours (p less than 0.05) after unilateral carotid ligation. GHB did not affect the ischaemic swelling of the brain.

Animals↗