Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.16.2 (PCP)
 3,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Blood conservation is gaining more and more interest because of the increasing risks involved in homologous blood transfusions. Acute normovolemic hemodilution (ANH) is becoming an established technique even in cardiac surgery patients. The "optimal" kind of volume replacement, however, is still controversial. Thus, this study was carried out to investigate the hemodynamic response of 6 different hydroxyethyl starch (HES) solutions as volume replacement. METHODS. In 60 patients undergoing elective aortocoronary bypass surgery, acute, preoperative hemodilution was performed (10 ml/kg) and HES with different concentrations, molecular weight, and substitution was infused according to a randomized sequence: 1. 6% HES 450,000/0.7; 2. 10% HES 200,000/0.5; 3. 3% HES 200,000/0.5%; 4. 6% HES 40,000/0.5; 5. 6% HES 200,000/0.5; 6. 6% HES 200,000/0.62. All patients were monitored using a new pulmonary artery catheter that allows measurement of the right ventricular ejection fraction (RVEF), right ventricular enddiastolic volume (RVEDV), and right ventricular end systolic volume (RVESV) in addition to standard hemodynamic parameters. RESULTS. Immediately after finishing ANH the typical hemodynamic changes of hemodilution (HD) were apparent (decrease in peripheral resistance and increase in cardiac index (CI]. All 6 solutions investigated were effective in hemodynamic stabilization (no changes in mean arterial pressure (MAP), filling pressures (PCP, RAP), or heart rate (HR]. Forty min after ANH, however (before beginning extracorporeal circulation (ECC], there were significant differences between the groups: in groups 3 and 4 the increase in CI had already disappeared, and SVI in group 3 was even lower than the baseline values (-8%). In the other groups, a higher CI level remained even 40 min after ANH, which was most pronounced in groups 2 (+40%) and 5 (+43%). Right ventricular performance was not changed by ANH (RVEF unchanged in all groups). Forty min after hemodilution RVEDVI (-8%) and RVESVI (-16%) decreased significantly only in group 4, whereas in the other groups these parameters were still elevated. The most pronounced positive fluid balance after the end of ECC was found in group 4 (+850 ml); in these patients paO2 decreased significantly (-150 mmHg). CONCLUSIONS. The guarantee of stable hemodynamic conditions is a prerequisite when performing ANH in coronary surgery patients. The different physiochemical attributes of various HES solutions seem to be important, thus influencing their hemodynamic response. In this study, low-concentration (3% HES 200/0.5) and low-molecular (6% HES 40/0.5) HES solutions were less effective in stabilizing hemodynamics until the beginning of ECC. Additionally, their negative influence on fluid balance during ECC, followed by a deterioration in pulmonary function led to the conclusion that other solutions are preferable; in particular, 10% HES seems to be of advantage in these situations.
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PMID:[The hemodynamic effects of various hydroxyethyl starch solutions in heart surgery patients]. 3185 74

We studied nine patients (56 +/- 7 years) with complete AV-block and permanent dual-chamber pacemaker (DDD) under different pacing modes: ventricle pacing (VVI) 70 bpm, DDD 106 +/- 4 bpm, rate adaptive pacing (VVI-FA) 108 +/- 3 bpm. Exercise was performed supine on the bicycle ergometer at 50 watts for 5 min at each setting. DDD-paced patients showed significantly higher mixed venous oxygen saturation, being 45 +/- 2% after the fourth minute, (VVI 38 +/- 2%, p less than 0.01 and VVI-FA paced patients 40 +/- 1%, p less than 0.01). Pressures were normal under DDD pacing during exercise (RAP 7 +/- 2 mm Hg; PCP 14 +/- 3 mm Hg) and showed further increase to abnormal levels during VVI (RAP 13 +/- 2 mm Hg, p less than 0.01; PCP 21 +/- 3 mm Hg, p less than 0.02) and VVI-FA pacing (RAP 10 +/- 2 mm Hg, p less than 0.05; PCP 20 +/- 3 mm Hg, p less than 0.01). Stroke volume increased from 71 +/- 5 ml to 105 +/- 7 ml during VVI and from 64 +/- 7 ml to 81 +/- 7 ml during DDD pacing. Stroke volume remained unchanged (69 +/- 5 ml) during VVI-FA pacing. The peak levels of ANP during and after exercise were significantly higher under VVI (951 +/- 248 pg/ml) than under DDD pacing (650 +/- 140 pg/ml, p less than 0.01) and were not different between DDD and VVI-FA pacing (677 +/- 97 pg/ml). These results show that VVI pacing effects a more pronounced increase of ANP level than other pacing modes. Under moderate exercise, rate-responsive pacing compared to VVI pacing showed no differences in mixed venous oxygen saturation and in atrial pressures. Only DDD pacing showed higher oxygen saturation and a normalization of atrial pressures when compared to other types of single chamber pacing.
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PMID:[Effect of AV synchronization and rate increase on hemodynamics and on atrial natriuretic peptide in patients with total AV block]. 214 4

A haemodynamic and M mode echocardiographic study of 57 patients hospitalised for chronic, symptomatic 2nd or 2rd degree AV block was carried out after 3 periods of pacing, each lasting 2 hours : 1) sequential AV pacing ( SAV ) with a 200 ms delay, considered as the mode of reference; 2) sequential ventriculo-atrial pacing ( SVA ) with the same sequential delay, recreating equivalent conditions of 1/1 ventriculo-atrial conduction (VAC); 3) ventricular pacing (V) recreating complete AV dissociation ( CAVD ). The pacing rate was the same for each patient (89 +/- 9/min). In comparison with SAV , SVA caused much worse haemodynamic changes than V : large increases in mean atrial pressures (+161% and +64% in RAP and PCP respectively); "canon" atrial A waves which were poorly tolerated (mean amplitude 14 mmHg and 18 mmHg on the RA and PCP waves respectively); in some cases, a large fall in blood pressure was observed due to the failure of systemic resistances to increase and compensate for the constant decrease in pump function (mean reduction of 23% of cardiac index; 29% of LV work index). These changes are much more pronounced in diseased than in healthy hearts, especially in the presence of mitral or tricuspid regurgitation. Echocardiography showed the main cause of these haemodynamic changes to be a reduction in ventricular filling with significant reductions in LV systolic and diastolic dimensions, changes in the mitral valve echos (reduction in the opening and closing velocities, delayed closure), probably related to a decrease in transvalvular blood flow, and decreased regional contractility of the interventricular septum. These observations justify an increase in the indications of modes of pacing maintaining permanent atrio-ventricular sequence (VVI pacing at slow rates; AAI pacing, DVI or DDD pacing in cases of abnormal AV conduction with VAC, especially in cases of sick sinus syndrome with permanent bradycardia). These modes of pacing are particularly beneficial when the electrical abnormality is associated with a decompensated cardiac lesion, or with decreased ventricular compliance or mitral regurgitation.
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PMID:[Hemodynamics and M mode echocardiography of the consequences of ventriculo-atrial conduction in the human]. 642 28

Haemodynamic and echocardiographic studies of isosorbide dinitrate were conducted in 12 patients (8 men and 4 women) with left ventricular failure consecutive to recent myocardial infarction. The groups: group I received 5 mg/h and group II 10 mg/h Risordan intravenously. After one hour treatment, group I patients showed a significant fall in both PAP (from 32.3 +/- 5.3 to 26.7 +/- 6.9 mmHg; p less than 0.01) and PCP (from 21.8 +/- 4.7 to 17.3 +/- 7.7 mmHg; p less than 0.05). These haemodynamic changes were amplified after a second hour of treatment: PAP fell to 24 +/- 7.9 mmHg (p less than 0.01) and PCP to 14.2 +/- 4.4 mmHg (p less than 0.001). RAP decreased from 7.2 +/- 5.1 to 3.5 +/- 5 (p less than 0.05). There were no changes in heart rate, systemic arterial pressure, peripheral resistance, cardiac index, forward stroke work nor, on echocardiography, in ventricular diameters, shortening fraction and VCF. After one hour treatment, group II patients showed a fall in PAP (from 30.5 +/- 4.7 to 21.7 +/- 3.5 mmHg; p less than 0.01), PCP (from 21.7 +/- 4.8 to 14.8 +/- 4.9 mmHg: p less than 0.001) and RAP (from 10.3 +/- 2.9 to 7.2 +/- 2; p less than 0.01). The systolic diameter of the left ventricle was reduced from 66.3 +/- 10.6 to 64.3 +/- 11.3 (p less than 0.01). After 4 hours, improvement in PAP and PCP was maintained; the other values remained stable. The effectiveness of Risordan i.v. in left ventricular failure consecutive to acute myocardial infarction is due to reduction of filling pressures in the left ventricule. With the 10 mg/h dose, as opposed to the 5 mg/h dose, the systemic arterial pressure and the double and triple products tend to be reduced, which suggests greater effectiveness.
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PMID:[Use of isosorbide dinitrate (Risordan) injection in left ventricular failure following acute myocardial infarction (author's transl)]. 711 Sep 69

To test the sensitivity and specificity of hemodynamic criteria for acute right ventricular infarction (RVI), two groups of patients with anatomically proved acute myocardial infarction and hemodynamic monitoring were studied. Group A included 22 patients acute RVI and group B, 38 with infarction confined to the left ventricle. In both groups, the closest relation between right atrial and pulmonary capillary pressures (RAP and PCP), as well as the presence of a severe noncompliant pattern (SNCP), were studied. A SNCP was defined as a y descent deeper than the x descent in RAP. RAP was equal to or higher than PCP in 10 patients from group A and in none from group B. In group B, a significant relation was found between RAP and PCP (r = 0.777, y = 0.43x + 0.18) (p less than 0.05), and the 95% confidence limits could be calculated. Above these limits, a closer relation between RAP and PCP was only found in patients with RVI. However, six patients with RVI showed an RAP/PCP relation within 95% confidence limits of group B (sensitivity 72.7%, specificity 100%). A SNCP was present in 12 patients with RVI and only in one without RVI (p less than 0.01) (sensitivity 54.5% and specificity 97.4%). When either criterion is present (close relation between RAP and PCP or SNCP), a high sensitivity (81.8%) and specificity (97.4%) can be achieved in the diagnosis of acute RVI.
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PMID:Sensitivity and specificity of hemodynamic criteria in the diagnosis of acute right ventricular infarction. 726 Dec 84