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PubMed2004

Hemodynamic changes of the cerebral circulation after stent-protected carotid angioplasty.

BACKGROUND AND PURPOSE: Stent-protected carotid angioplasty (SPAC) is an option for treating cervical symptomatic high-grade internal carotid artery (ICA) stenosis. So far, knowledge about hemodynamic changes in the early postinterventional phase is limited. The purpose of this study was to evaluate these changes. METHODS: Thirty-four consecutive patients with a high-grade ICA stenosis (according to European Carotid Surgery Trial criteria) and 10 healthy volunteers were enrolled. Hemodynamics of the cerebral circulation were assessed before and within 6 hours after SPAC. ICA flow volume, cerebral blood volume flow (CBVF), and collateral flow volume were sonographically assessed. The ratio of flow velocities in the middle cerebral artery (MCA) ipsilateral to the ICA stenosis was calculated and compared with that in the contralateral MCA. This ratio was designated rMCA. RESULTS: Preinterventional CBVF, ICA flow volume, and rMCA were significantly reduced compared with results in healthy volunteers. After SPAC, CBVF, ICA flow volume, and rMCA increased significantly. The rMCA did not exceed 1.0. Collateral flow volume decreased in patients with posterior collateral flow only. Postinterventional CBVF and ICA flow volume in patients did not differ from values in healthy volunteers. CONCLUSION: Cerebral hemodynamics appear to be impaired in patients with symptomatic high-grade ICA stenosis. After SPAC, hemodynamic parameters normalize within 6 hours. We did not detect hyperperfusion. However, flow volume in the contralateral ICA remains increased in patients with former anterior cross-filling.

Adult↗
PubMed2004

[Aerobic and hemodynamic mechanisms of the antianginal effect of drugs in patients with angina pectoris].

Paired bicycle ergometric tests were performed to study the basic features of the aerobic hemodynamic mechanism of antianginal effects of reference representatives of the major classes of antianginal drugs (AADs) (nitrosorbide, corinfar, propranolol) in 54 patients with Functional Classes II-IV angina pectoris (AP). Oxygen consumption and central hemodynamic parameters were studied during exercise. The efficiency of a single administration of the drugs was 53-62%. In the context of the whole organism, AADs increased exercise tolerance in patients with AP, by optimizing oxygen-supplying processes: by reducing oxygen uptake, on the one hand, and by improving oxygen delivery to working organs, on the other. In so doing, corinfar-induced activation of the oxygen-transporting system resulted from the higher hemodynamic productivity; propanolol enhanced hemodynamic effectiveness, nitrosorbide showed a combination of both effects.

Angina Pectoris↗
PubMed2004

Comparison of hemodynamics during hyperthermal immersion and exercise testing in apparently healthy females aged 50-60 years.

BACKGROUND: Owing to excessive worries regarding adverse cardiac events, hyperthermal balneotherapy for patients with coronary artery disease is underprescribed. However, very few cardiac events occur in similar heat stress during Finnish sauna bathing. Exercise testing has proven to be a safe diagnostic procedure even in survivors of myocardial infarction. METHODS: We compared the effects of hyperthermal immersion and exercise testing on cardiac hemodynamics in 21 apparently healthy women aged 50-60 years. The maximal symptom-limited bicycle exercise test was performed according to the modified protocol of Wasserman. Hyperthermal immersion was carried out in 40 degrees C water and was completed by increasing the core temperature by about 2 degrees C. The left ventricular function was evaluated using continuous measurement of thoracic electric bioimpedance during both tests. The blood pressure, index of contractility and heart rate were measured directly, whereas the cardiac index, left cardiac work index and systemic vascular resistance index were calculated. RESULTS: The hemodynamic response, as assessed at continuous non-invasive monitoring, showed substantial differences between hyperthermal immersion and exercise testing. Overall, we found a significantly lower hemodynamic load during hyperthermal immersion in comparison with exercise testing. Entering the bath, there was a significant decrease in the left cardiac work, contractility and blood pressure. We recorded a slight increase in the heart rate towards peak hyperthermal immersion. However, other modulators such as the mean arterial pressure, index of contractility, cardiac index and left cardiac work index decreased even below resting values. CONCLUSIONS: Excessive hyperthermal immersion induced a lower hemodynamic load in apparently healthy women than standard maximal exercise testing.

Analysis of Variance↗
PubMed2004

Coronary sinus venoarterial CO2 difference in different hemodynamic states.

Myocardial metabolic rate and coronary flow are closely related limiting thus the diagnostic value of coronary sinus saturation monitoring as an indicator of flow. Regional venoarterial CO2 gradient was found elevated during low flow in various clinical and experimental conditions, in animals and humans. This study was undertaken to examine the impact of the variations of cardiac mechanical work on veno-arterial CO2 content and partial pressure difference (deltaPCO2) of the coronary sinus blood. Twenty-seven patients of either sex (m/f = 21/6), undergoing coronary artery bypass grafting under extracorporeal circulation, were studied. Monitoring included a Swan-Ganz catheter and a coronary sinus line. The correct position of the late was verified by the waveform displayed in the monitor. Immediately after cannulae placement, a hemodynamic profile was obtained and simultaneous arterial and coronary sinus sampling for blood gas analysis was done in an ABL 720 (Radiometer Copenhagen) analyzer. A second collection of the same data was obtained five minutes later with the patients in a slight "head-down" position. Conditions for exclusion was intersample variation of hemoglobin's concentration greater than 15% and sodium ion concentration difference greater than 10% of the greater value. Arteriovenous oxygen partial pressure difference (deltaP(a-cs)O2), veno-arterial carbon dioxide partial pressure difference (deltaP(cs-a)CO2), O2 & CO2 content difference and heart's respiratory quotient were calculated and correlated to cardiac output (CO) and the other hemodynamic parameters. Statistical analysis employed t-paired test and linear regression. No ischemia was detected during sampling. "Head-down" position had a significant impact to all hemodynamic parameters except heart rate. In both data rows, although CO ranged widely and altered significantly, coronary sinus oxygen saturation and arteriovenous O2 content difference were stable and showed insignificant correlations to all the hemodynamic parameters that were studied. Carbon dioxide content difference (coronary sinus-arterial) showed a trending of decrease with higher flow. DeltaP(cs-a)CO2 appeared stable and independent of flow. Finally, respiratory quotient decreased significantly from 0.91 +/- 0.4 to 0.86 +/- 0.4 (mean +/- SD; p < 0.05). The heart's high basal oxygen consumption and the almost near hemoglobin's desaturation transcoronary extraction of oxygen limits the value of coronary sinus saturation monitoring as indicator of coronary flow. Heart's little extraction reserve is faced with coronary flow reserve. In the physiologic range and under the conditions of anesthesia, elevated CO2 production is accompanied with increased coronary flow. Under these circumstances, deltaP(cs-a)CO2 appears stable and is not suitable for clinical decisions concerning heart's coronary flow.

Aged↗
PubMed1992

Long-term sympathetic and hemodynamic responses to clonidine in patients with cirrhosis and ascites.

The aim of the present study was to examine the short- and long-term effects of the alpha 2-agonist clonidine on sympathetic overactivity, systemic, splanchnic, and renal circulation changes, and abnormal renal sodium excretion in cirrhotic patients with ascites. Of 17 patients, 8 received clonidine and 9 a placebo. Measurements were taken before and after either a single dose of clonidine (150 micrograms) and placebo or a 1-week treatment with clonidine (150 micrograms/day) and placebo. Clonidine but not placebo induced significant short- and long-term decreases in plasma norepinephrine concentrations in the pulmonary artery and the right renal vein. Acute clonidine administration induced a significant reduction in cardiac output, heart rate, arterial pressure, and hepatic venous pressure gradient but had no effect on renal hemodynamics. Long-term clonidine administration induced a significant decrease in the hepatic venous pressure gradient from 20.1 +/- 1.9 to 17.6 +/- 2.0 mm Hg (mean +/- SEM) but had no significant effects on systemic or renal hemodynamics or renal excretion of sodium. It is concluded that long-term clonidine administration in cirrhotic patients induced a sustained decrease in sympathetic nervous activity and portal pressure. In contrast, clonidine had no prolonged effect on systemic hemodynamics. In addition, short- and long-term clonidine administration did not modify renal hemodynamics or induce a natriuretic response in patients with ascites.

Ascites↗
PubMed2004

[Significance of hemodynamic changes and monitoring value of patients with severe hepatitis during perioperative orthotopic liver transplantation].

OBJECTIVE: To observe the hemodynamic changes of the patients with severe hepatitis during orthotopic liver transplantation (OLT). METHODS: Ten patients with severe hepatitis received liver transplantation. The pulmonary artery catheter was inserted into right jugular vein and an arterial line was put in the left radial artery. Hemodynamics parameters including cardiac output (CO), arterial blood pressure (ABP), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), cardiac index (CI) at different time points were observed. RESULTS: During the operation, HR was increased, and ABP was significantly decreased at the beginning of anhepatic period and neo-hepatic period. Central venous pressure (CVP) was significantly decreased during anhepatic period and profoundly increased in the early neo-hepatic phase, then declined to normal range progressively. Pulmonary capillary wedge pressure (PCWP) changed in accordance with the variation of pulmonary arterial pressure (PAP). Both of them were significantly decreased during anhepatic period and profoundly increased in the early neo-hepatic phase. SVR was at a lower level before operation, and gradually increased during anhepatic period, then significantly declined at the beginning of anhepatic period. PVR had the most marked changes during the neo-hepatic period, gradually decreased to the pre-operation level after significant elevation at the early neo-hepatic phase. Left ventricular stroke work index (LVSWI) was profoundly declined from the beginning of anhepatic period to the 1 minute after neo-hepatic phase, then progressively increased. Right ventricular stroke work index (RVSWI) was significantly decreased during anhepatic period, then progressively increased during neo-hepatic period. CO and CI maintained at a higher level, significantly declined during anhepatic period compared with pre-anhepatic period and gradually increased to a higher level than peri-operation. CONCLUSION: Remarkable changes in hemodynamics of patients with severe hepatitis during liver transplantation are found especially at the early phase of anhepatic and neo-hepatic, while CO maintained at a higher level, together with a complicated changes in SVRI. Monitoring hemodynamics during peri-operation has its value to prevent and manage cardiac insufficiency and low blood volume.

Adult↗
PubMed1992

[Hemodynamic differences do not exist in patients with adult respiratory syndrome with or without infection].

BACKGROUND: To verify whether patients with adult respiratory distress syndrome (ARDS), associated to sepsis or not, may be differentiated according to the values of the hemodynamic variables. METHODS: Thirty-two consecutive patients with ARDS admitted to an intensive care unit over a period of 32 months were prospectively studied. In 18 patients ARDS was associated to sepsis. The value of the hemodynamic variables were compared between both groups of patients (18 with sepsis and 14 without) within the first 24 hours of diagnosis of the syndrome. RESULTS: Mortality of patients with ARDS associated with sepsis was greater than in those without sepsis (78% vs 57%). In general both groups of patients with ARDS presented similar values of pulmonary hypertension (28 +/- 6 and 25 +/- 4 mmHg) with elevated pulmonary vascular resistance, and with an above normal cardiac index and ventricular function parameters. No significant differences were found in hemodynamic values, ventricular function and oxygen transport among patients with ARDS, with or without sepsis, or among survival or death in each group, or those considered in general. CONCLUSIONS: This study demonstrated that patients with the septic adult respiratory distress syndrome (ARDS) have the same hemodynamic changes as those observed in patients with ARDS without sepsis. This absence of differences may be explained by the presence of mechanisms common in sepsis and ARDS.

Adult↗
PubMed1992

[Assessment of right ventricular function using gated blood pool single photon emission computed tomography in inferior myocardial infarction with or without hemodynamically significant right ventricular infarction].

Right ventricular function was assessed using gated blood pool single photon emission computed tomography (GSPECT) in 10 normal subjects and 14 patients with inferior myocardial infarction. Three-dimensional background subtraction was achieved by applying an optimal cut off level. The patient group consisted of 6 patients with definite hemodynamic abnormalities indicative of right ventricular infarction (RVI) and 8 other patients with significant obstructive lesion at the proximal portion of right coronary artery without obvious hemodynamic signs of RVI. Right ventricular regional wall motion abnormalities were demonstrated on GSPECT functional images and the indices of right ventricular function (i.e. the right ventricular ejection fraction (RVEF), the right ventricular peak ejection rate (RVPER) and the right ventricular peak filling rate (RVPFR)) were significantly reduced in the patient group, not only in the patients with definite RVI but also in those without hemodynamic signs of RVI. The present study indicates that inferior infarction is frequently associated with RVI, even in the absence of definite hemodynamic signs, when the proximal portion of right coronary artery is obstructed. It is concluded that GSPECT is reliable for the assessment of right ventricular function and regional wall motion, and is also useful for the diagnosis of RVI.

Hemodynamics↗
PubMed2005

Poststenotic flow and intracranial hemodynamics in patients with carotid stenosis: transoral carotid ultrasonography study.

BACKGROUND AND PURPOSE: In severe carotid stenosis, blood supply via the poststenotic internal carotid artery (ICA) and collateral pathways determine cerebral perfusion. We investigated whether poststenotic flow on transoral carotid ultrasonography (TOCU) is predictive of cerebral hemodynamics. METHODS: Eighty-eight patients with unilateral carotid stenosis underwent TOCU to analyze blood flow velocity and poststenotic diameter of the extracranial ICA. Intracranial collaterals and cerebral hemodynamics were assessed with selective angiography and single photon emission CT. RESULTS: Poststenotic diameter (P <.0001) and velocities (peak systolic velocity [PSV], time-averaged mean velocity [TMV], end-diastolic velocity [EDV]; all P < or = .009) decreased with stenotic severity. Poststenotic diameter was correlated with PSV (r=0.36, P=.0005), EDV (r=0.32, P=.002), and TMV (r=0.39, P=.0001). Poststenotic flow was significantly lower with collateral pathways than without pathways (P < or = .02) and significantly decreased as the number of the collaterals increased (P <.0001). Flow <5 mL/s indicated collaterals (81% sensitivity, 80% specificity). When flow was <5 mL/s, the asymmetry index in the middle cerebral artery (MCA) territory was significantly low during rest (P=.003) and after acetazolamide challenge (P=.006). Poststenotic flow velocity was associated with baseline (P=.007) and postacetazolamide (P=.0009) MCA asymmetry indexes. CONCLUSION: Poststenotic ICA flow measured with TOCU reflects collateral flow and cerebral hemodynamics in patients with severe carotid stenosis. This technique may provide new parameters for screening patients with hemodynamically significant carotid stenosis.

Acetazolamide↗
PubMedDate not supplied

[Alterations of cardiac output during bicarbonate hemodialysis and its relationship with other hemodynamic parameters].

PURPOSE: Time course of cardiac output (CO) and other hemodynamic parameters were measured during hemodialysis (HD). Our aims were to identify a characteristic CO profile and investigate the relationship with other hemodynamic parameters. PATIENTS AND METHODS: CO was measured with ultrasound dilution method in 45 chronic hemodynamically stable HD patients. Diabetics and patients with heart diseases were excluded. Ultrafiltration rate (UFR) was fixed at 649 +/- 244 mL/min. Pre/post statistical comparisons were performed for CO, cardiac index (IC), central blood volume (CBV) and total peripheral resistance (TPR). RESULTS: CO was pre 5.7 +/- 1.8 and post 4.5 +/- 1.4 L/min (p=0.001); IC was pre 3.2 +/- 0.9 and post 2.6 +/- 0.7 L/m2 (p=0.001); CBV was pre 1.28 +/- 0.39 and post 1.09 +/- 0.32 L (p=0.001). TPR increased from 18.7 +/- 5.6 to 22.7 +/- 6.1 mmHg/L/min (p=0.001). Maximal CO reduction rate was found at 60 min, thereafter it reduced progressively. Log(CO1) increased in a non-linear way with body weight gain and similarly it decreased during UFR. A negative correlation was found between log(TPR1) and log(CO1-QA). CO reduction was associated with UFR and not with age, dialysis duration, left ventricular hypertrophy, sex and hemoglobin (Hb) in a multiple regression model (r2 =0.31, p=0.05). Qa/CO1 was 0.16 +/- 0.12. CBV/CO increased from 0.23 +/- 0.06 to 0.25 +/- 0.07%. CONCLUSIONS: Progressive CO reduction and TPR increase appear to be the typical hemodynamic features of bicarbonate HD with a UFR of moderate degree. Volume overload and CO increase were related in a non-linear way. TPR1 was strongly correlated with CO1-Qa, suggesting that a large arterovenous shunt was associated with increased resistance.

Adult↗
PubMed2005

[Predictors of hemodynamically successful left pulmonary artery stent implantation in patients after repair of tetralogy of Fallot].

OBJECTIVES: Left pulmonary artery stenosis is a well-known postoperative complication in patients with tetralogy of Fallot. Recently, balloon expandable intravascular stents have been widely used to relieve those lesions. However, the increase in left pulmonary blood flow is not adequate in some patients, although the vessels are suitably dilated. This study evaluated the predictors of hemodynamical improvement. METHODS: The study population consisted of nine patients with morphologically successful stent implantation for left pulmonary artery stenosis after repair of tetralogy of Fallot. Patients were divided into two groups. Four patients had hemodynamical improvement by stent implantation, with relative perfusion of the left lung of over 30% of total pulmonary perfusion. The other five patients had relative perfusion of the left lung of under 30% of total pulmonary perfusion after stent implantation. The timing of stent implantation and the morphological features of pulmonary artery were compared between the two groups. RESULTS: In hemodynamically improved patients, the stent implantation was performed earlier(6.1 +/- 3.5 vs 16.1 +/- 6.5 years old, p = 0.029), and the interval between surgical repair and stenting was shorter (3.7 +/- 2.7 vs 11.3 +/- 4.7 years, p = 0.025). There was no difference in the left pulmonary artery diameter after stenting, but the right pulmonary artery diameter was significantly smaller in hemodynamically improved patients (99.0 +/- 23.7 vs 135.0 +/- 15.1% normal, p = 0.027). CONCLUSIONS: Effective stent implantation for left pulmonary artery stenosis in patients with tetralogy of Fallot after repair must be performed before compensatory right pulmonary artery growth occurs.

Arterial Occlusive Diseases↗
PubMed2005

Hemodynamics of graded water immersion in the baboon: +Gz protection potential.

INTRODUCTION: Fluid-filled anti-G suits depend on external fluid counterpressure to maintain near-normal hemodynamics during +Gz (head-to-foot inertial force). However, the relationship between external fluid level, hemodynamic events, and +Gz tolerance has not been determined. METHODS: Seven anesthetized male baboons (avg. wt. = 27.2 kg) were catheterized for measurement of left ventricular pressure (LVP), right ventricular pressure (RVP), aortic BP (ABP), central venous pressure (CVP), pulmonary artery pressure, cardiac output, and esophageal pressure. The animals were seated in a restraint chair and control data were collected, followed by six discrete steps of water immersion (WI): 1) knee; 2) hip; 3) xiphoid; 4) mid-chest; 5) neck; and 6) return to the xiphoid (data check). Each level was maintained until hemodynamic stabilization. Rectal temperature averaged 33.5 degrees C; water bath temperature was maintained at 34 degrees C. RESULTS: There was a significant (p < 0.05) increase in most hemodynamic parameters with WI to the xiphoid, mid-chest, and neck. With WI to the neck, CVP, LV, and RV end diastolic pressures increased by 8.7 mmHg, 19.6 mmHg, and 8.0 mmHg, respectively, suggesting a major passive increase in thoracic and cardiac blood volume, whereas mean ABP (MABP) increased by 18.6 mmHg and total peripheral resistance significantly decreased. Heart rate did not change significantly. CONCLUSION: The increase in MABP with WI to the neck would provide slightly more than +1 Gz relaxed protection. Additional +Gz would require pressure breathing to overcome the increased external hydrostatic pressure on the thorax. Water-filled anti-G suits filled to the xiphoid cannot provide adequate relaxed +Gz protection for current high performance aircraft without supplemental factors such as additional pressure in the suit or positive pressure breathing.

Adaptation, Physiological↗
PubMed2005

[Stress, hemodynamic and immunological responses to inhaled and intravenous anesthetic techniques for video-assisted laparoscopic cholecystectomy].

OBJECTIVE: Given the immunomodulatory effects of anesthesia and surgery, 2 anesthetic regimens in clinical use were compared to evaluate hemodynamic, stress, and immunologic response in patients undergoing laparoscopic cholecystectomy. PATIENTS AND METHODS: Randomized controlled trial in patients classified ASA I and scheduled for laparoscopic cholecystectomy. Patients were randomly assigned to the inhaled anesthetic group (13 anesthetized with propofol-fentanyl-isoflurane) or the total intravenous anesthesia (TIVA) group (14 patients anesthetized with propofol-remifentanil). Patients in both groups received the muscle relaxant vecuronium. We assessed hemodynamic variables, cortisol levels, prolactin, interleukin 6, white cell and lymphocyte counts before, during (1 hour after induction) and after (24 hours and 7 days) surgery. RESULTS: Hemodynamic variables were stable in both groups. Significant changes in prolactin levels and markers of immune and inflammatory responses between baseline and later measurements occurred in both groups. Patients who received TIVA had no change in cortisol levels at any time during the study. The TIVA group had lower levels of cortisol than did the inhaled anesthesia group (TIVA, 207 [SD, 100] ng/mL; inhaled 293 [97] ng/mL; P<0.05)), higher neutrophil counts (TIVA, 75 [12.5]%; inhaled: 62 [20]%; P<0.05) and higher CD4+ T lymphocyte counts (TIVA, 53 [11.6]%; inhaled: 42 [17.6]%; P<0.001). CONCLUSION: Although both techniques afford hemodynamic stability, lower cortisol levels were observed with the application of TIVA with propofol-remifentanil. That would be the technique of choice for patients with compromised immune response.

Adult↗
PubMed2005

The significance of clinical markers in the prediction of hemodynamic and cardiac complications of capnoperitoneum in patients at risk.

OBJECTIVES: The aim of this prospective study was to find out the predictive value of concomitant diseases of cardiovascular system (CVS), lungs and kidneys as well as metabolic diseases to be able to anticipate the potential origin of hemodynamic and cardiopulmonary complications as a result of insufflated CO2 peritoneum. METHODS: The study investigated eleven patients at the anaesthetic risk of ASA III-IV and cardiac risk of NYHA II-III in whom elective laparoscopic surgical intervention had been indicated. RESULTS: We have found out that the significance of the increase in biologic ANP markers, catecholamines and PRA was not sufficient to signal the deepening of cardiac dysfunction, latent cardiac failure or hemodynamic disorder (p > 0.01). The courses of regression lines have shown the dependence on the increased IAP (intra-abdominal pressure) of capnoperitoneum in PRA and adrenaline. The reactions of biologic markers correlated with reactions of clinical hemodynamic markers of BP and HR. We have proved that the increased level of IAP causes a significant increase in CVP (p < 0.01) being one of the factors determining the preload of right ventricle (RV) and in coincidence with intact transpulmonary circulation also the optimal function of left ventricle (LV). CONCLUSION: Our investigation of peroperative clinical and biologic markers of hemodynamics and neuroendocrine response to operative stress and development of CO2 peritoneum has proved that the course of laparoscopic operations in patients in the risk group of ASA III-IV and NYHA III does not necessarily have to be deteriorated by complications. It can be assumed that increased values of biologic markers regulate the neurohumoral response in the physiologic range and do not predict a severe CVS dysfunction within its course. (Tab. 2, Fig. 3, Ref. 22.)

Abdomen↗
PubMed1979

[Hemodynamic guidelines in the treatment of acute myocardial infarction by means of vasodilators].

Two types of vasodilators are used for treatment of acute myocardial infarction: Nitrates on the one hand with predominant venodilation and agents like Phentolamie and Nitroprusside on the other hand with venodilation as well as arteriolar vasodilation. Different opinions exist with respect to indication of these vasodilators. They are used for reduction of arterial blood pressure, for reduction of left ventricular filling pressure and for increase of cardiac output. A marked decrease in ejection fraction is the hemodynamic basis of application of vasodilators in the latter indication. By reduction of peripheral vascular resistance emptying of the left ventricle in these patients is enhanced.) As a working hypothesis in clinical situation elevated filling pressure indicates a decreased ejection fraction. The first part of this investigation deals with relation of left ventricular and diastolic pressure to ejection fraction. A good correlation between these two parameters was found in 717 patients with coronary artery disease. However variability was so wide that regression from enddiastolic pressure to ejection fraction in the individual seemed impossible. In 26.6% of patients with ejection fraction over 0.6%, filling pressure was 20 mm Hg or more. On the other hand, in 34.7% of patients with ejection fraction below 0.3% filling pressure was 20 mm Hg or less. As a consequence of practical value, reduced ejection fraction has to be assumed, if a patient presents elevated filling pressure and reduced cardiac output. In the second part, the hemodynamic effects of Phentolamine in 12 patients with acute myocardial infarction and elevated filling pressure (PCV resp. PADP greater than 18 mm Hg) are described. Maximal effects on hemodynamic variables were: reduction of peripheral vascular resistance by 31.4%, of left ventricular filling pressure by 16.2%, and of mean arterial pressure by 17.0%. Cardiac output increased by 25.8% and heart rate rose by 14.8%. At optimal efficacy, stroke volume increased by 23.7%. Further increase of infusion rate with concomitant fall of peripheral vascular resistance resulted in decrease of stroke volume and tachycardia. Most serious side effects consisted in sudden fall of blood pressure. Therefore intraarterial monitoring of blood pressure is demanded. The third part deals with hemodynamic effects of nitrates (Isosorbiddinitrate 10 mg p.o.) in patients with acute myocardial infarction and elevated filling pressure. One hour after application peripheral vascular resistance decrease by 16.5%, filling pressure by 20.8%, and mean arterial pressure by 9.0%. Cardiac output stroke volume and heart rate did not change significantly. No side effects were observed with Isosorbiddinitrate although two cases of nitrate syncope occurred with Nitroglycerin, resulting in bradycardia and hypotension. Indications for vasodilator therapy therefore has to be handled as follows: Nitrates should be given to patients with elevated filling pressure and normal cardiac output...

Arrhythmias, Cardiac↗
PubMedDate not supplied

[Hemodynamic effects of levosimendan following cardiac surgery].

The hemodynamic effect of levosimendan was compared to that of dobutamine in a trial enrolling 30 adults undergoing scheduled cardiac surgery with cardiopulmonary bypass. Fifteen patients were randomly assigned to receive levosimendan in a single dose of 18 microg x kg(-1) followed in 15 to 20 minutes by start of infusion at a rate of 0.2 microg x kg(-1) min(-1) for 24 hours (levosimendan group). Another 15 randomized patients received dobutamine infused at a rate of 7.5 microg x kg(-1) min(-1). Hemodynamic parameters were measured before starting infusion of the drug and after 24 hours of treatment. Changes in the main hemodynamic parameters were as follows. In the levosimendan group heart rate (beats/min) was 87.15 (SD 10.22) at baseline and 87.91 (6.00) at 24 hours; mean arterial pressure (mm Hg) was 83.96 (10.57) at baseline and 86.41 (13.29) after 24 hours; cardiac index (L/min/m2) was 2.21 (0.23) at baseline and 2.53 (0.35) at 24 hours; systemic vascular resistance (dyn/sec(-1)/cm(-5)) was 1436.74 (311.48) at baseline and 1378.35 (320.68) at 24 hours. In the dobutamine group heart rate (beats/min) was 84.28 (2.18) at baseline and 96.02 (9.10) after 24 hours; mean arterial pressure (mm Hg) was 83.59 (9.05) at baseline and 74.29 (6.33) at 24 hours; cardiac index (L/min/m2) was 2.16 (0.28) at baseline and) 3.02 (0.34) at 24 hours; systemic vascular resistance (dyn/sec(-1)/cm(-5)) was 1578.93 (334.88) at baseline and 1136.68 (158.60) at 24 hours. We found that mean arterial pressure and both systemic and pulmonary vascular resistance decreased significantly in the levosimendan group (P < 0.05), but not in the dobutamine group. On the other hand, both heart rate and cardiac index increased in the levosimendan group only (P < 0.05). We conclude that levosimendan improves hemodynamic stability in patients who have undergone cardiac surgery and that it is a good alternative for treating postoperative low cardiac output syndrome.

Adult↗
PubMed2005

Aortic valve replacement with new-generation stentless pericardial valves: short-term clinical and hemodynamic results.

BACKGROUND AND AIM OF THE STUDY: Aortic valve replacement (AVR) with stentless bioprostheses offers superior hemodynamics. In order to overcome the disadvantages of older, stentless valves, a new generation of pericardial stentless prostheses has been developed. Herein, the hemodynamic and clinical results of these substitutes have been evaluated. METHODS: Between March 2002 and May 2004, 85 patients (59 females, 26 males; mean age 73.6 +/- 6.1 years) who underwent AVR received either a bovine (Sorin Pericarbon Freedom; SPF; n = 50) or an equine (3F Aortic Bioprosthesis; 3F; n = 35) pericardial stentless valve. Patients were followed up prospectively at six months after surgery by clinical and echocardiographic examination. The mean follow up period was 5.6 +/- 0.8 months, and was 96.4% complete. RESULTS: Mortality was 2.4% at 30 days (two SPF patients; one died at reoperation for suspected valve thrombosis and one was a non-valve-related death) and 2.5% at follow up (two SPF patients; both nonvalve-related). Neither structural valve failure nor endocarditis were observed. Preoperatively, there were no differences in baseline data, functional status and hemodynamics between SPF and 3F patients. The aortic cross-clamp time was similar in both groups (51.7 +/- 11.2 min for SPF; 51.6 +/- 8.2 min for 3F). NYHA functional status improvement was similar in each group (1.8 +/- 0.5 for SPF; 1.7 +/- 0.6 for 3F). The mean transaortic pressure gradient (deltapmean) was reduced in all patients during follow up. With SPF, a lower deltapmean was found for smaller aortic roots (indexed annular diameter (IAD) < 14 mm/m2) as well as in larger (IAD > 14 mm/m2) aortic roots: 8.0 +/- 4.5 mmHg versus 13.2 +/- 7.2 mmHg (p < 0.05) and 6.8 +/- 3.0 mmHg versus 12.8 +/- 4.8 mmHg (p < 0.05), respectively. CONCLUSION: New-generation pericardial stentless aortic valves are very pliable, which facilitates their implantation. Clinical and hemodynamic results with these prostheses are promising. The SPF prosthesis demonstrates excellent performance, and may be superior when implanted in small aortic roots.

Aged↗
PubMed2005

[Effects of different levels of positive end expiratory pressure on lung recruitment and hemodynamics after sustained inflation in acute respiratory distress syndrome in sheep].

OBJECTIVE: To study the effects of different levels of positive end expiratory pressure (PEEP) on recruitment and hemodynamics after sustained inflation in acute respiratory distress syndrome (ARDS) in sheep. METHODS: Twelve adult sheep were anaesthetized and ARDS was induced by lung lavage with warm normal saline. Pressure-volume (P-V) curves were traced using the low flow technique and the upper inflection point (UIP) was determined. Sustained inflation was exercised at the pressure of 5 cm H(2)O (1 cm H(2)O=0.098 kPa) below UIP, and the sheep were divided into groups according to different PEEP levels (PEEP5, PEEP10, PEEP15, PEEP20). Hemodynamics and lung mechanics values were recorded during the 2 hours of recruitment, and biopsy was performed at the end of the trial. RESULTS: There was no effect on hemodynamics and recruitment in 2 hours in PEEP5 and PEEP10 groups, but oxygenation was found to be decreased in PEEP5 group, and focal alveolar collapse was found in pathological examination. When the PEEP level reached 15 cm H(2)O, there was significant elevation in central venous pressure (CVP), and cardiac index (CI) fell remarkably, but oxygenation index and lung mechanics were improved and stable in 2 hours. CONCLUSION: Our study demonstrates that it can obviously improve oxygenation when PEEP is set at 10-20 cm H(2)O, oxygenation can be obviously improved, with little disturbance to hemodynamics in case cardiac function is normal.

Animals↗