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Effect of clonidine therapy on renal hemodynamics in renal transplant hypertension.

Antihypertensive medications have a variable effect on renal hemodynamics and may contribute to renal insufficiency in some patients. Since clonidine has actually been found to improve renal hemodynamics in patients with essential hypertension, we studied the effects of clonidine therapy in patients with renal transplant hypertension. Baseline measurements of BP and renal hemodynamics were made in six patients after two weeks of therapy with furosemide. Clonidine was then added and titrated until BP was controlled. Repeated measurements of renal hemodynamics were made four and 16 weeks after clonidine therapy was begun. Glomerular filtration and effective renal plasma flow as assessed by inulin and aminohippurate sodium clearances were preserved during prolonged clonidine therapy.

Adult↗

[Nocturnal sleep and cerebral hemodynamics in different sleep stages and cycles among patients with early manifestations of cerebral circulatory insufficiency].

Clinical and polygraphical (EEG, EOG, EMG, ECG, REG) studies of nocturnal sleep and of the hemodynamics were carried out in 60 patients with dyscirculatory encephalopathy induced by hypertension and atherosclerosis. The findings obtained demonstrate that the clinical picture in these patients is always characterized by sleep disturbances which decrease the level of their diurnal wakefulness and their capacity for work. Hemodynamic disturbances responsible for sleep disorders are in turn maintained by the latter which leads to the formation of the vicious circle. This is also supported by the fact that compromized cerebral circulation causes changes in the activity of the structures involved both in sleep-wakefulness function and the regulation of the cerebral and systemic hemodynamics. Hence, deviations in the nocturnal sleep pattern attended with pronounced alterations in the cerebral hemodynamics may contribute to the development of acute disorders of the cerebral circulation. The authors recommend correcting not only the disrupted structure of sleep but also the cerebral circulation with relation to he sleep-wakefulness cycle.

Cerebrovascular Circulation↗

Hemodynamic effects of antiarrhythmic drugs in acute myocardial infarction.

The hemodynamic effects induced by an i.v. administration of Amiodarone (5 mg/Kg in 10 min + continuous infusion of 0.6 mg/min for 4-40 hrs), Propafenone (1-2 mg/Kg in 5 min + continuous infusion of 10-15 mcg/Kg/min for 24 hrs) and Mexiletine (250 mg in 15 min + 250 mg in 1 hr) have been evaluated in patients with acute myocardial infarction complicated by sinus tachycardia and hyperdynamic pattern, ventricular or supraventricular arrhythmias. The hemodynamic serial determinations have been comprehensive of: heart rate; systolic, diastolic and mean pressure; central venous pressure; arterial and wedge pulmonary pressure; cardiac output and cardiac index; vascular systemic resistences; left ventricular stroke work index; left ventricular mean ejection rate; double and triple product. In all of the three groups we observed: a reduction of cardiac index associated with an increase of left and right ventricular filling pressure and a reduction either of left ventricular stroke work index and left ventricular mean ejection rate; these hemodynamic changes were less significant after Mexiletine than after Amiodarone or Propafenone. These data confirm the negative inotropic effect of the three drugs; anyhow, these changes are usually well tolerated by patients affected by AMI with a sufficiently preserved ventricular function. The authors, however, reccommend an accurate hemodynamic monitoring of the effects of the drugs also to identify patients with a not overt ventricular failure which may become manifest after drug administration.

Amiodarone↗

[Effects of a postpituitary extract and lysine vasopressin on portal and systemic hemodynamics in the cirrhotic patient].

The purpose of this work was to study the hemodynamic effects of a pituitary extract (Post-Hypophyse, Choay, EPH) and of lysine vasopressin (Diapid, Sandoz, VP). Cardiac, pulmonary and liver hemodynamics were measured in 50 cirrhotic patients before and during intravenous infusion (0.45 IU/kg/h) of EPH (24 patients) or VP (26 patients). EPH and VP did not have identical consequences in cardiac output and systemic resistances. EPH significantly increased cardiac output and significantly decreased systemic resistances while VP significantly and increased systemic resistances. Both vasoactive drugs similarly decreased myocardial performances. EPH and VP had a moderate influence on WHV/IVC pressure gradient. This was variable from one patient to another. The decrease of WHV/IVC pressure gradient observed during EPH infusion was mainly related to an increase of IVC pressure. Since the effects of both drugs on WHV/IVC pressure gradient are slight and unpredictable and they exert an important effect on cardiopulmonary hemodynamics, caution should be taken in administering EPH or VP to cirrhotic patients. The clinical use of EPH or VP should be undertaken only when cardiac and liver hemodynamics monitoring are available.

Cardiac Output↗

[Electrocardiographic changes and hemodynamic comparisons in arterial hypertension].

The electrocardiographic criteria for left-ventricular loading were studied in patients with non-complicated arterial hypertension and were juxtaposed to the basic hemodynamic indices, determined via radio-isotope method--quantitative radiocardiography. Regular changes in the hemodynamics and electrocardiographic criteria were found, in the initial phases within the limits of the norm, and in the later ones--exceeding it. The method of correlation analysis was applied between the separate hemodynamic indisec and electrocardiographic criteria for left ventricular loading both in the separate subgroups and for the whole group. Correlation dependence with various values and sign were found. Finally, it was concluded that the classic electrocardiographic criteria for left ventricular loading in case of arterial hypertension obtained a new meaning and should be assessed with consideration given to the subjects' age and in a comparison with hemodynamic characteristic.

Adolescent↗

Central hemodynamic responses to venous, aortal or portal infusion of live E. coli bacteria in the cat.

The central hemodynamic responses were studied in experimental sepsis in cats, following various routes of infusion of live E. coli bacteria. The aortic blood flow (ABF) was electromagnetically recorded. The pulmonary artery was cannulate for pressure recording. Platelet and white blood cell concentrations, PO2, PCO2, pH and oxygen saturation were measured at intervals. I.v. infusion of bacteria induced initially decreased ABF, systemic hypotension, pulmonary hypertension. Portal infusion evoked, on the other hand, increased ABF, but induced no significant change in systemic or pulmonary arterial blood pressures. Aortal infusion induced responses in between. The initial hemodynamic changes were followed by relative normalization after 5-10 min. Then, in all series, a progressive fall in ABF and systemic blood pressure were noticed. Within 5 min following bacterial infusion the platelet and white blood cell concentrations fell to 65 and 50%, respectively. In all series a moderate metabolic acidosis developed. Thus, the initial hemodynamic response following infusion of live E. coli was dependent on the route of infusion; intraportal infusion induced initially a more hyperdynamic state. The different initial central hemodynamic responses did not influence the subsequent development of a hypotensive shock state.

Animals↗

[Characteristics of central and regional hemodynamics in certain variants of the course of myocardial infarct].

In 96 patients with myocardial infarction the indices of central hemodynamics were studied by radiocardiography and the indices of regional circulation in the brain, lungs, liver, and distal parts of the extremity by rheoplethysmography. Peculiarities of regional and central hemodynamics depending on the clinical picture were revealed and the dynamics of the indices being studied were followed from the first to the 40th day of the disease. The authors discuss the mechanisms of the hemodynamic disorders and express their opinion on the expediency of the appropriate approaches to the treatment of patients depending on the hemodynamic changes revealed.

Adult↗

Hemodynamic changes induced by supraventricular tachycardia.

In nine patients (pts.) with recurrent SVT, we have performed a combined electrophysiological and hemodynamic study. Five pts. showed reciprocating nodal tachycardia and 4 pts. reentry tachycardia associated with WPW syndrome (2 with Kent bypass tract and 2 with James bypass tract). Hemodynamic parameters were recorded during sinus rhythm (SR), atrial (AP) and ventricular pacing (VP) and following the initiation of SVT. The arrhythmia was induced by rapid atrial pacing or with atrial or ventricular premature stimuli. Hemodynamic data were then compared. Our results point out a greater hemodynamic deterioration during SVT than during AP or sinus tachycardia at similar rates. We have often observed in SVT, and constantly in A-V nodal reentrant (AVN) cases, the appearance of giant waves in the right and left atrium. This finding confirms hypothesis of the primary role of the changes in atrioventricular contraction sequence during SVT, especially in AVN tachycardias, with subsequent reduction in stroke volume and cardiac output.

Adolescent↗

[Hemodynamic effects of dobutamine in patients with severe low-output heart failure (author's transl)].

We studied the hemodynamic effects of dobutamine in 10 patients with severe chronic heart failure due to congestive cardiomyopathy in 5, to ischemic heart disease in 4 and to hypertensive cardiomyopathy in 1. Dobutamine was injected during three periods of 30 min each alternated with equal periods of placebo at doses of 2,5-5 and 7,5 mcg/Kg/min respectively. The most favorable hemodynamic effects, obtained at an infusion rate of 5 mcg/Kg/min, was characterized by a significant inn 4 and to hypertensive cardiomyopathy in 1. Dobutamine was injected during three periods of 30 min each alternated with equal periods of placebo at doses of 2,5-5 and 7,5 mcg/Kg/min respectively. The most favorable hemodynamic effects, obtained at an infusion rate of 5 mcg/Kg/min, was characterized by a significant increase of the cardiac index and of the left ventricle stroke work index, accompanied by a significant decrease of the left ventricular filling pressure and of the systemic and pulmonary vascular resistance. The hemodynamic monitoring showed that the pharmacological effects of the drug subsided about 5-10 min after the interruption of infusion. At the infusion rate of 7,5 mcg/Kg/min we observed a significant increase of premature ventricular beats in 3 patients. We conclude that dobutamine at the dose of 5 mcg/Kg/min shows a powerfull positive inotropic action not accompanied by apparent side effects.

Adult↗

Hemodynamic responses to anesthetic induction with midazolam or diazepam in patients with ischemic heart disease.

Hemodynamic responses to induction of anesthesia with midazolam maleate and diazepam were compared in patients with ischemic heart disease. While breathing 100% oxygen, 10 patients (group M) received midazolam maleate, 0.2 mg/kg, and 10 patients (group D) received diazepam, 0.5 mg/kg. In addition, 10 patients (group MN) breathing 50% nitrous oxide in oxygen received midazolam, 0.2 mg/kg. Patients in group M had a small but statistically significant (p less than 0.05) decrease (vs awake control values) in systemic and pulmonary arterial blood pressure, pulmonary arterial occluded pressure, stroke index, and left and right ventricular stroke work indices. Patients in group D experienced statistically significant decreases in systemic blood pressure. The only statistically significant differences between groups M and D occurred 5 minutes followed drug administration: heart rates were higher and systemic pressures and left ventricular stroke work indices were lower following midazolam. Hemodynamic changes following midazolam and nitrous oxide were similar to those observed in patients given midazolam and 100% oxygen. Patients in all three groups responded to endotracheal intubation with transient increases in blood pressure, heart rate, and systemic vascular resistance, but the hemodynamic values spontaneously returned toward control levels within 2 to 5 minutes. Although differing somewhat, midazolam, like diazepam, provided rapid, hemodynamically stable induction of anesthesia in patients with ischemic heart disease.

Anesthetics↗

Dobutamine: a hemodynamic evaluation in human septic shock.

The hemodynamic effect of dobutamine infusion (DI) was studied in 19 patients with septic shock. DI resulted in hemodynamic improvement as indicated by a significant increase in cardiac index (+36%, p less than 0.001), stroke index (+15%, p less than 0.01), mean arterial pressure (+20%, p less than 0.01), and a significant decrease in aVDO2 (-27%, p less than 0.01). This hemodynamic improvement occurred concomitantly with a fall in both right and left filling pressures. Mean systemic arterial resistance remained unchanged with a scatter of individual responses depending on other factors, such as infusion rate, initial vascular resistance, and underlying hemodynamic setting. In patients mechanically ventilated, venous admixture in the lung (Qs/Qt) during DI increased significantly (+30%, p less than 0.001) and insignificantly reduced PaO2, but this adverse effect was not observed when PEEP was used in patients mechanically ventilated. It is concluded that dobutamine can be useful in management of septic shock, particularly when filling pressures are high because of fluid overload or cardiac failure.

Adult↗

Studies on heart failure in old age (Part II). Hemodynamic effects of propranolol and isoproterenol in elderly patients with heart failure.

Hemodynamic responses to propranolol and isoproterenol were examined in elderly patients with heart failure. The results obtained are as follows: 1. Patients with mild heart failure showed greater reduction than control group in heart rate and cardiac output after intravenous propranolol. These enhanced hemodynamic responses to propranolol would be the evidence of increased adrenergic activity even in mild heart failure. 2. Intravenous propranolol in the small dosage of 0.03 mg/kg showed only a negligible hemodynamic deterioration even in patients with heart failure. 3. Hemodynamic responses to beta-adrenergic stimulator, isoproterenol, were depressed in severe heart failure.

Aged↗

[Intracardiac hemodynamic characteristics in high-degree mitral stenosis and an assessment of the indications for its surgical treatment].

The data from the right cardiac catheterization, echocardiography M-type and radiocardiography were juxtaposed in 54 patients with "pure" or predominating severe mitral stenosis (MS)(mitral valvular opening under 1 cm2)--confirmed at operation, in the determination of their functional and hemodynamic characteristics. The patients were grouped into three groups depending on the degree of pulmonary--capillary pressure increase (PC)--greater than 2.666, greater than 3.999 and 4.132 kPa(greater than 20, greater than 30 and less than 31 mmHg). The first group covering 28 per cent of the patients with a mean PC--2,399 +/- 0.257 kPa = (18 +/- 1.93 mmHg) are of particular interest. A light to moderate increase of pulmonary arterial pressure, elevated TPVR, absence of right ventricular insufficiency with reduced M. V SI resp. were established in them. It was assessed as a group with hypovolemia and proper preoperation preparation but requiring attention as regards the eventual hypotension, intra- or post operation. The third group covers 22 per cent of the patients and is characterized with increased TPVR, high hypertension in pulmonary artery, elevated telediastolic pressure in right ventricle and normal or lightly increased MO, assessed as a group with an inadequate diuretic therapy pre-operatively. The second group is with typical hemodynamic characteristics of severe MS and includes 50 per cent of the patients. The analysis forces the conclusion, that for an adequate evaluation of hemodynamics and MS severity, the PC pressure is necessary to be always discussed in connection with blood volume and flow, as well as with the other hemodynamic indices, in order to avoid the omissions as regards MS operability.

Adult↗

Effects of acetylsalicylic acid on peripheral hemodynamics in patients with chronic heart failure treated with angiotensin-converting enzyme inhibitors.

Cyclooxygenase inhibitors may affect the hemodynamic status of patients with heart failure adversely and may also block the vasodilatory effects of angiotensin-converting enzyme (ACE) inhibitors in such patients. Relatively low doses of the cyclooxygenase inhibitor acetylsalicylic acid (ASA) are now used routinely in ischemic heart disease, the most important cause of heart failure. Therefore, we investigated the hemodynamic interaction between ASA and captopril in heart failure. In a randomized, cross-over study, 13 patients with congestive heart failure (CHF) who were already receiving maintenance treatment with an ACE inhibitor received a single dose of 25 mg captopril combined with 236 mg ASA or placebo. Peripheral blood flow was studied noninvasively by venous occlusion plethysmography of the calves. Liver blood flow was estimated from indocyanine green (ICG) clearance. Administration of captopril alone significantly decreased blood pressure (BP), and ICG clearance. Calf blood flow remained unchanged. However, after arterial occlusion, hyperemic calf blood flow persisted for longer. Captopril alone did not significantly change the plasma levels of the vasodilating prostaglandins PGI2 and PGE2 or the vasoconstricting thromboxane A2 (TXA2). In contrast, captopril combined with ASA reduced the plasma levels of these vasoactive substances, with significant decreases in PGE2 and TXA2 as compared with captopril alone, yet the hemodynamic alterations after captopril plus ASA were similar to those observed after captopril alone. A single antithrombotic dose of ASA (236 mg) in 13 patients with CHF [New York Heart Association (NYHA) class II-IV] undergoing chronic treatment with ACE inhibitors had no discernible effect on hemodynamic status.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Interrelationships between systemic hemodynamics, urinary sodium excretion, and renin-angiotensin system in cirrhosis.

We studied the interrelationships between systemic hemodynamics, sodium excretion and the renin-angiotensin system in 28 nonazotemic cirrhotic patients on a sodium restricted diet. Renal hemodynamics were also assessed. The patients were divided into three groups. Group A comprised 9 patients without ascites or edema; group B comprised 8 patients with ascites and relatively high sodium excretion (41.9 +/- 12.9 mmol/day); and group C comprised 11 patients with ascites and very low sodium excretion (4.8 +/- 12.9 mmol/day). There were no significant differences in urine flow, glomerular filtration rate or effective renal plasma flow between the three groups of patients, although renin and aldosterone levels were significantly increased in group C. Groups A and B did not differ in hemodynamic parameters and no differences were found between the three groups in heart rate or in plasma volume. Group C, however, showed significantly higher cardiac index and lower arterial pressure and systemic vascular resistance. Plasma volume was inversely related to systemic vascular resistance, and natriuresis correlated significantly with both cardiac index (inversely) and systemic vascular resistance (directly). In addition, renin and aldosterone levels were inversely correlated with both mean arterial pressure and systemic vascular resistance. The systemic hemodynamic disturbances in nonazotemic cirrhotics is paralleled by the impairment in sodium homeostasis, suggesting that the decrease in systemic vascular resistance is the primary event leading to hypotension, high cardiac output and the activation of the renin-angiotensin system in these patients.

Adult↗

[The effect of radon baths at Khmel'nik health resort on the central hemodynamic indices, on thyroid function and on adrenal glucocorticoid function in hypertension patients].

As many as 63 patients with stage I, II hypertensive disease were examined. Characteristics of central hemodynamics were studied by means of tetrapolar thoracic rheography, the content of thyroid-stimulating hormone, thyroxin, triiodothyranine, hydrocortisone were determined by radioimmunologic method. All investigations were done before and after the patients having radon baths. Hypotensive effect of radon baths in hyperkinetic type hemodynamics was manifested by a significant drop in cardiac index and increase in specific peripheral resistance. In hypokinetic type hemodynamics there was a significant fall in average hemodynamic pressure, and improvement of the arteriole patency. The levels of thyroxin and hydrocortisone have raised significantly. The Khmel'nik health resort radon baths have hypotensive effect in HD patients, enhance the function of the thyroid gland and glucocorticoid function of the adrenals.

Adrenal Glands↗

[Intramuscular and oral clonidine in premedication of the heart surgery patient: hemodynamic effects and interaction with high-dose fentanyl induction].

OBJECTIVE: The aim of the study was to evaluate the efficacy of oral and i.m. clonidine as premedication in reducing the requirements of fentanyl for induction and to analyze its effects on the hemodynamics of patients with ischemic heart disease. SETTING: University Hospital. MATERIALS AND METHODS: The authors considered 30 patients (27 male and 3 female) undergoing CABG. Patients were premedicated 60-90 min before induction of anesthesia and were randomly distributed in three groups: Group A: oral diazepam 0.1 mg x kg -1; Group B: oral diazepam 0.1 mg x k-1 + oral clonidine 5 micrograms x kg-1; Group C: oral oral diazepam 0.1 mg kg-1 + i.m. clonidine 4 micrograms x kg-1. Induction of anesthesia was realized with fentanyl at speed of 500 mcg x min-1 until loss of consciousness was reached (no answer to three consecutive questions). MEASUREMENT: Hemodynamic data were recorded at TO(baseline), T1(induction of anesthesia), T2(3 min after intubation), T3(3 min. after skin incision). Results were analyzed by utilizing the average comparison Student "t" test and paired "t" test. A value of p < 0.05 was regarded as statistically significant. MAIN RESULTS: In groups B and C the inductive dose of fentanyl was much lower (p < 0.001) compared to control group (B = 19.23 +/- 3.57 micrograms x kg-1; C = 19.92 +/- 4.15 micrograms x kg-1; A = 28.39 +/- 6.4 micrograms x kg-1). This difference remained statistically significant (p < 0.001) also at T2 and T3 (T1: A = 42.79 +/- 3.21 mcg x kg-1; B = 29.07 +/- 6.18 micrograms x kg-1; C = 29.84 +/- 5.46 micrograms x kg-1; T2: A = 57.28 +/- 5.32 micrograms x kg-1; B = 43.22 +/- 3.87 micrograms x kg-1; C = 43.48 +/- 4.25 micrograms x kg-1). Considering the hemodynamic data, we report the heart rate in group B increased at T2 (p < 0.01), and systolic artery pressure raised in groups A (p < 0.05) and C (p < 0.01) at T2. Compared to baseline cardiac index showed a decrement at T3 in all groups of patients (p < 0.05). Systemic vascular resistance increased in all groups at T3 compared to baseline (p < 0.05). CONCLUSIONS: Clonidine proved to be useful to reduce narcotic requirements and to provide hemodynamic stability.

Administration, Oral↗

Hemodynamic effects of 0.375% versus 0.25% bupivacaine during cervical epidural anesthesia for hand surgery.

BACKGROUND AND OBJECTIVES: Cervical epidural anesthesia with 0.375% or 0.25% bupivacaine plus fentanyl is a reliable technique for surgical restoration of digital motion-after tourniquet release and rehabilitation. The study was designed to assess the hemodynamic effects of this technique in 11 ASA 1 patients. METHODS: The epidural catheter was introduced at the C7-T1 interspace on the day of operation. The volume of 0.375% bupivacaine necessary to block the brachial dermatomes was determined. The day after (day 1), every patient received epidurally the determined volume of 0.375% bupivacaine plus 1 microgram/kg fentanyl (group A). On day 2 the same volume of 0.25% bupivacaine plus 1 microgram/kg fentanyl (group B) was injected. For each patient one or several pairs of injection (A + B) were performed in relation with duration of rehabilitation. Cardiac index, stroke volume index, end diastolic index, ejection fraction, and systemic vascular resistance were studied by thoracic electrical bioimpedance. These parameters, mean arterial pressure and heart rate were recorded before and after injection. Sensory level was assessed by loss of cold sensation. RESULTS: Nineteen paired injections were performed. Mean volume of bupivacaine was 7.1 +/- 2 mL. The caudad sensory level was lower in group A: T7 (T3-L1) versus T6 (T2-T11) in group B. Hemodynamic variables were not different between the 2 groups. Mean arterial pressure cardiac index, heart rate, stroke volume index, and ejection fracture decreased slightly as end diastolic index remained unchanged and systemic vascular resistance increased slightly. No correlation was found between hemodynamic changes and spread of analgesia. CONCLUSIONS: Hemodynamic effects, in ASA 1 patients, are moderate and not dependent on the studied concentration of bupivacaine, indicating that a similar degree of sympathetic block is achieved with 0.375% and 0.25% bupivacaine.

Adult↗