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Emmeran Gams

Publications and source records attributed to Emmeran Gams.

28 records · Page 2Linked to original sources
PubMed2005

Anticoagulation during extracorporeal circulation under conditions of an ongoing systemic inflammatory response syndrome: effects of heparin.

OBJECTIVE: Open-heart surgery with cardiopulmonary bypass (CPB) causes changes in haemostasis. Artificial surfaces are bioincompatible and, thus, may initiate a reaction similar to an acute inflammation. In some patients, this 'postperfusion syndrome' (PPS), which includes changes in haemostasis, is the beginning of a systemic inflammatory response syndrome (SIRS). However, it is not clear whether the changes in coagulation represent a consequence or a main cause of the inflammatory reaction. Thus, the aim of our study was to investigate the cascade of coagulation and the effects of heparin under special circumstances of an ongoing SIRS. METHODS: In a prospective evaluation using standardized operative procedures with CPB, we compared Group A (control group with normal postoperative course, n =20) with Group B (patients with postoperative SIRS, n =12). At six time points beginning before and ending two days after surgery, we measured platelet counts, leucocyte counts and plasma levels of fibrinogen, factor XII and antithrombin III (ATIII), in addition to standard coagulation tests (PTT, TT and ACT). Furthermore, we determined parameters of inflammation, such as C-reactive protein, PCT, IL-6, IL-8, IL-10 and TNF-alpha. RESULTS: In Group B (SIRS), we found a reduced anticoagulation during CPB with significantly lower values for PTT (60+/-7 versus 160+/-11 s), ACT (270+/-33 versus 532+/-44 s) TT (40+/-3 versus 150+/-15 s) compared to the control Group A. Simultaneously, we found a significant increase of factor XII in the SIRS group (191+/-16 versus 10+/-2%). There were no significant differences concerning the preoperative ATIII levels and the intraoperative dosage of heparin; the intraoperative decrease of fibrinogen, ATIII and platelets was comparable in both groups. Furthermore, we could see that significant changes of inflammatory parameters in the SIRS group (increasing levels of TNF-alpha, Il-6, IL-8 and IL-10) occurred at least 30 min after the observed reduction of anticoagulatory effect. CONCLUSIONS: With our results, it could be demonstrated that the development of inflammatory complications after CPB is correlated to a significantly reduced intraoperative effect of heparin. As this reduction of anticoagulation significantly preceded the changes of inflammatory parameters in SIRS patients, we think that a hypercoagulatory state, especially in cases of ongoing inflammation, is an additional trigger of SIRS.

Aged↗
PubMed2004

[Protective effects of a delta-opioid-receptor agonist and an oxygen radical scavenger on postischemic hearts].

BACKGROUND AND PURPOSE: The cardioprotective effects of delta-opioid receptor agonists is mediated-at least in part-via oxygen radicals. Mannitol that is used in cardiac surgery because of its osmotic properties exerts its beneficial effects on stunned myocardium via scavenging hydroxyl radicals. The effects of a delta-opioid receptor agonist (D-Ala2-D-Leu5-Enkephalin [DADLE]), the radical scavenger mannitol and their combination on postischemic dysfunction in rabbit hearts were investigated. METHODS: Isolated, blood-perfused rabbit hearts were subjected to a 20-min global, normothermic, no-flow ischemia that was followed by a 60-min reperfusion. Systolic and diastolic ventricular function as well as coronary blood flow (CBF) were assessed. The hearts were assigned to one of four groups: 1. placebo (n = 6); 2. DADLE (n = 8; 430 nM); 3. mannitol (n = 7; 8.6 mM); 4. DADLE + mannitol (n = 7). RESULTS: Ischemic contracture in the DADLE and the mannitol group was significantly smaller compared with the placebo group. Contracture was smallest in the DADLE + mannitol group. The postischemic function in the placebo group was drastically reduced (p < 0.05), while it was best preserved in the DADLE + mannitol group. CBF and MVO(2) were changed similarly in all groups (n. s.). The external efficiency was significantly higher in the groups with DADLE and/or mannitol than in the placebo group. Both DADLE and mannitol exhibit cardioprotective properties. Combination of both substances exerts an additive, positive effect on the ischemic contracture. Noteworthy, the protective effects of DADLE during reperfusion were not antagonized by the oxygen radical scavenger mannitol. On the other hand, DADLE + mannitol did not augment the protective effects of the single substances during reperfusion, except for the isovolumic LVP(max). CONCLUSION: Both substances improve the postischemic systolic and diastolic function and the relation between cardiac work and oxygen needed for this work. Thus, both substances offer promising properties in the clinic.

Analgesics, Opioid↗
PubMed2004

Coronary flow reserve in hypertrophic obstructive cardiomyopathy assessed by intracoronary Doppler catheter.

BACKGROUND: In spite of progress in diagnosis and treatment, hypertrophic obstructive cardiomyopathy (HOCM) remains a serious medical problem. Among many issues, the pathophysiology of the coronary circulation in HOCM has not yet been fully examined. AIM: To assess coronary flow reserve in HOCM. METHODS: The study group consisted of 15 patients (6 males, 9 females, mean age 51+/-15 years) with typical echocardiographic signs of HOCM and without stenosis of the coronary arteries. Using an intracoronary Doppler catheter, the average peak velocity and the absolute coronary flow reserve were determined in the proximal, medial and distal parts of the left anterior descending (LAD) and the circumflex coronary artery (Cx) following administration of papaverine, substance P, and during pacing. The coronary square plane was calculated angiographically after substance P injection. The retrograde coronary flow and the relationship between the increase of the coronary square plane and the coronary flow reserve were also examined. RESULTS: Under pharmacological stimulation, higher values of the average peak velocity were observed compared to pacing. A retrograde flow was observed in 8 of 10 patients in the LAD and in 3 of 8 patients in the Cx. The coronary flow reserve was higher under pharmacological stress than during pacing. No relationship was found between the increase of the coronary square plane and the coronary flow reserve. CONCLUSIONS: No decrease in the coronary flow reserve was observed in our patients with HOCM which, however, does not exclude the possibility of ischaemia based on subordinate vessels and microcirculation changes. In the majority of patients a retrograde flow was detected.

Adult↗
PubMed2003

Norepinephrine-induced delayed cardioprotection against stunning is at the expense of a higher postischemic arrhythmia rate.

OBJECTIVE: alpha(1)-adrenoceptor activation confers myocardial protection from ischemic injury. We tested whether norepinephrine mediates delayed cardioprotection against stunning and whether this alters postischemic arrhythmias. METHODS: New Zealand White rabbits were assigned to three groups: Control-group (n=7): no drugs. Norepinephrine-group (n=7): 75 microg norepinephrine/kg bodyweight (bw). Norepinephrine/prazosin-group (n=7):75 microg norepinephrine and 15 microg prazosin/kg bw. After 24 h, hearts were excised, perfused with buffer and subjected to 20 min of ischemia followed by 120 min of reperfusion. RESULTS: (a) Developed pressures (dP) (P(syst)-P(diast)) at the end of reperfusion: C: 51.2+/-5.0%, NE: 71.7+/-5.1% (p<0.05 vs. C), NEP: 50.7+/-5.0%. (b) Ventricular extra beats (vebs) were detected throughout the experiments. C: 0.41+/-0.15 vebs/min, NE: 1.06+/-0.18 vebs/min (p<0.05 vs. C), NEP: 1.17+/-0.3 vebs/min. CONCLUSION: Norepinephrine confers delayed preconditioning against myocardial stunning via an alpha(1)-adrenoceptor mediated pathway. Norepinephrine-mediated preconditioning involves a beneficial effect towards stunning, but at the expense of a higher rate of postischemic ventricular arrhythmia.

Adrenergic alpha-Agonists↗
PubMed2003

Effects of direct mechanical ventricular assistance on regional myocardial function in an animal model of acute heart failure.

Direct mechanical ventricular assistance (DMVA) improves hemodynamics in failing hearts without complications associated with a blood/device interface. Epicardial Doppler displacement transducers provide exact measurements of tissue displacement and regional myocardial function (RMF). An in vivo porcine model of acute heart failure was used to examine the effects of DMVA on RMF, which have not been reported before. In 8 anesthetized pigs cardiac output (CO), left ventricular pressure (LVP), aortic blood pressure (BP), systolic contractility (dp/dt max), and systolic wall thickening fraction (WT%) were measured. A multichamber pump system (IMPS) surrounding the left ventricle was implanted and the measurements were repeated. Then acute heart failure was induced by beta-blockade, resulting in a decline of all measured parameters to more than 30% compared to baseline values. In the further course of the experiment, repeated measurements were taken at several intervals with and without DMVA by the implanted device. The IMPS implantation caused no significant hemodynamic changes. Under conditions of acute heart failure DMVA improved LVP (46 +/- 7 to 81 +/- 9 mm Hg), dp/dt max (532 +/- 207 to 744 +/- 361 mm Hg/s), CO (1.5 +/- 0.1 to 1.9 +/- 0.5 L/min) and WT% (19 +/- 7% to 32 +/- 8%). Left ventricular myocardium not directly assisted by external pressure application showed improved regional myocardial function during DMVA. We conclude that DMVA is capable of improving hemodynamics due to extrinsic compression. It also enhances the remaining myocardial function of the failing heart, which might lead to myocardial recovery. These synergistic effects are considered responsible for the high efficiency shown by the IMPS in previous investigations.

Acute Disease↗
PubMed2002

[The isolated rabbit heart: comparison between five different modifications].

BACKGROUND: The isolated heart as an experimental model has been firmly established for more than 100 years. MATERIAL AND METHODS: In this study, five modifications are compared: 1. modified Langendorff apparatus (LA) with modified Krebs-Henseleit (KH) solution a) not containing bovine serum albumin (BSA; n = 13) and b) containing BSA (n = 16), 2. LA with KH solution containing BSH and bovine erythrocytes (n = 14), 3. LA with support rabbit (n = 6), and 4. "working heart" preparation with KH solution, BSA and bovine erythrocytes (n = 16). In the latter modification, no balloon was inserted into the left ventricular cavity, i. e., systemic and coronary circuits were not separated from each other. After completion of the preparation and 20-min stabilization, hemodynamic and metabolic data were assessed while the hearts were contracting in the ejecting mode. Thereafter, protocols for different studies were performed that are not presented here. However, the stability of the modifications within their individual protocols is reported. RESULTS: The results suggest that hearts perfused with KH solution are well suited for short protocols. In spite of the additional costs and time, blood perfusion is required for long-lasting protocols or if changes in coronary flow are to be investigated. CONCLUSIONS: The working heart exhibits both the best function and stability at a relatively low experimental expenditure. Yet, it is not suited for studies where perfusion pressure needs to be changed independent of arterial pressure.

Animals↗
PubMed2002

Preconditioning: myocardial function and energetics during coronary hypoperfusion and reperfusion.

BACKGROUND: Ischemic preconditioning (IP) is gaining more acceptance as a protective method in beating heart surgery. Yet it remains controversial whether preconditioning can attenuate myocardial dysfunction during reperfusion after severe coronary hypoperfusion. We examined this issue and also the issue of whether this protection is mediated by adenosine A1 receptors. METHODS: In isolated, blood-perfused rabbit hearts, the effects of IP (3 minutes of no flow ischemia and 8 minutes of reperfusion) during 30 minutes of coronary hypoperfusion and 60 minutes of reperfusion were investigated. In two groups (n = 8 each) with and without (control group) preconditioning, ventricular function was assessed by load-insensitive measures: slope of the end-systolic pressure-volume relation (Emax), slope of the stroke work/end-diastolic volume relation (Mw), and end-diastolic pressure-volume relation. External efficiency was calculated, and contractile efficiency was assessed using the reciprocal of the myocardial oxygen consumption-pressure-volume area relationship. To investigate the possible role of adenosine, the adenosine A1 receptor antagonist DPCPX (2.5 micromol/L) was administered before preconditioning in a third group (n = 7). RESULTS: The effects of hypoperfusion on systolic function, diastolic function (dP/dtmin, end-diastolic pressure-volume relation), external efficiency, and contractile efficiency were similar in both the IP and control groups. Lactate efflux was significantly reduced after preconditioning (p = 0.02). During reperfusion, recovery of systolic function and coronary flow were significantly improved in the IP group compared with controls: aortic flow, 85% versus 63% (p = 0.01); dP/dtmax, 91% versus 67% (p = 0.001); pressure-volume area, 97% versus 68% (p = 0.01); Emax, 74% versus 62% (p = 0.03); and Mw, 94% versus 84% (p = 0.04). Release of creatine kinase was reduced in the IP group, 9.6 +/- 1.3 U x 5 min(-1) x 100 g(-1) wet weight, versus controls, 12.7 +/- 2.7 U x 5 min(-1) x 100 g(-1) wet weight (p = 0.04). During reperfusion, contractile efficiency (p = 0.03) and external efficiency (p = 0.02) recovered better in preconditioned than in untreated hearts. Recovery was less pronounced in the DPCPX group compared with the IP group (p, not significant). CONCLUSIONS: The results, derived from load-insensitive measures, confirm that IP provides protection after episodes of severe hypoperfusion by attenuating systolic dysfunction without improving diastolic dysfunction and reduces the severity of anaerobic metabolism as well as ischemic injury. Contractile efficiency and external efficiency both indicate improved energetics after IP (oxygen utilization by the contractile apparatus). The protective effect, at least in part, is mediated by adenosine A1 receptors.

Animals↗
PubMed2002

Flow cytometry analysis of platelet cyclooxygenase-2 expression: induction of platelet cyclooxygenase-2 in patients undergoing coronary artery bypass grafting.

There are conflicting reports about the expression of cyclooxygenase (COX)-2 in human platelets. The present study describes a flow cytometric method for the measurement of platelet COX. Both COX-1 and COX-2 were shown to be expressed in platelets from patients undergoing a coronary artery bypass graft. There was a significant increase in COX-2 expression at day 5 as compared with pre-surgery values (mean fluorescence 12.31 +/- 0.88 versus 9.15 +/- 0.88; means +/- SEM, n = 7, P < 0.05), whereas COX-1 levels did not change (13.45 +/- 1.11 versus 12.38 +/- 1.41; n = 7, P > 0.05).

Aspirin↗
PubMedDate not supplied

Resting pulmonary ventilation in sports scuba divers.

It should be investigated whether the traditional dependency between respiratory and systemic measures is preserved during scuba diving, and whether the diving experience would affect respiration. Additionally, respiration data were analyzed for gender differences (118 sports divers). Respiratory variables were assessed at poolside and during diving in the pool. The respiration pattern at poolside was significantly different from the pattern during diving, where respiration rate (RR) decreased (11.8 +/- 3.8 vs. 7.8 +/- 2.9 min(-1); -34%) and tidal volume increased (1.1 +/- 0.5 vs. 1.6 +/- 0.6 L; +45%). This produced a decrease in respiratory minute volume (RMV) from 12.4 +/- 4.7 to 11.2 +/- 3.8 L/min (-10%). Respiratory Minute Volume and vital capacity correlated at poolside. This physiologic correlation was lost while diving. Instead, RMV and number of dives (= diver's experience) correlated negatively. Because RMV at both poolside and during diving correlates with RR, an increased RMV in diving beginners can be estimated via RR. Thus, close observation of RR could help improve safety during a regular dive, avoiding hazardous hyperventilation. Female divers, irrespective of body height and weight, need less air during diving.

Adolescent↗