Effects of phenylephrine on the sublingual microcirculation during cardiopulmonary bypass.

BACKGROUND: The objective of the present study was to investigate sublingual microvascular blood flow and microcirculatory haemoglobin oxygen saturation (Smc(O(2))) during cardiopulmonary bypass (CPB) using constant systemic blood flow but different perfusion pressures achieved by phenylephrine administration. METHODS: Fifteen patients undergoing coronary artery bypass grafting were enrolled in this pilot study. Systemic haemodynamics, oxygen transport variables, arterial and mixed venous blood gas analysis, and microcirculatory variables were determined after initiation of general anaesthesia, during CPB (systemic blood flow=2.4 litre m(-2)), after increasing perfusion pressure by 20 mm Hg with a continuous infusion of phenylephrine, and after termination of phenylephrine infusion. RESULTS: CPB immediately resulted in a significant (P<0.05) decrease in systemic oxygen transport without alterations in sublingual microcirculatory blood flow and Smc(O(2)). Increasing perfusion pressure from 47 (SD 9) to 68 (7) mm Hg using phenylephrine=1.4 (1.0) microg kg(-1) min(-1) resulted in a significant decrease in sublingual small vessel blood flow (from median 2.5 to 1.8 arbitrary units) representing mostly capillary blood flow, but not in medium-sized vessels (median 3 to 2.8 arbitrary units). Concurrently, global tissue blood flow from 110 (54) to 197 (100) perfusion units and Smc(O(2)) increased from 72 (11)% to 84 (7)%, suggesting significant microcirculatory blood flow shunting in vessels with diameters >25 microm. CONCLUSIONS: Our data demonstrate that an increased perfusion pressure produced by phenylephrine at constant CPB flow may decrease microcirculatory blood flow in the sublingual mucosal microcirculation due to microvascular blood flow shunting.

Ongoing procedure development in robotically assisted totally endoscopic coronary artery bypass grafting (TECAB).

BACKGROUND: Totally endoscopic coronary artery bypass grafting (TECAB) using robotics requires stepwise introduction into a heart surgery program. It is the aim of this study to evaluate the state of procedure development after continued application of telemanipulation techniques in the clinical setting. We also sought to assess perioperative and intermediate term clinical results after robotically assisted CABG. PATIENTS AND METHODS: From June 2001 to March 2005, robotically assisted CABG using the daVinci system was carried out in 107 patients with single and multi-vessel coronary artery disease. The following procedures were performed: robotically assisted endoscopic left internal mammary artery (LIMA) harvesting and completion of the procedure as conventional CABG, MIDCAB, or OPCAB (n = 22), robotically assisted suturing of LIMA-to-LAD anastomoses during conventional CABG (n = 28), TECAB on the arrested heart using remote access perfusion (n = 48), TECAB on the beating heart using an endostabilizer (n = 8), takedown of adhesions (TECAB intended) (n = 1). RESULTS: Hospital mortality was 0% and cumulative risk adjusted mortality reached 1.6 lives saved versus EuroSCORE predictions. Undesirable surgical events (USE) such as conversion, on table revision, or postoperative revision procedures occurred in 34 out of 107 (32%) patients. Median ventilation time and ICU stay, however, were 11(0-278) hours and 21(11-389) hours, respectively. Cumulative 3 years survival was 100% and freedom from angina at 3 years was 97%. CONCLUSIONS: We conclude that despite being surgically challenging robotically assisted coronary artery surgery can be implemented with acceptable safety. TECAB procedures have reached a reproducible state. Perioperative mortality after robotically assisted CABG may be lower than predicted. Intermediate term clinical results are very satisfactory.

Polyneuropathies in critically ill patients: a prospective evaluation.

OBJECTIVE: To determine the incidence, severity and course of polyneuropathies in patients with sepsis or systemic inflammatory response syndrome combined with multiple organ failure. DESIGN: Prospective study. SETTING: Division of Intensive Care Medicine of the Department of Anesthesiology and Intensive Care and Intensive Care Unit of the Department of Neurology, University Hospital Innsbruck, Austria. PATIENTS: Twenty-two patients between 23 and 77 years old with sepsis or systemic inflammatory response syndrome combined with multiple organ failure fulfilling strict inclusion and exclusion criteria. INTERVENTIONS: Clinical neurologic examination and electro myography/nerve conduction velocity measurements during the stay on the Intensive Care Unit and 2-3 months later. MEASUREMENTS AND RESULTS: In 9 of the 22 patients signs of polyneuropathy were found at the initial clinical investigation and in 7 patients at the follow-up investigation. Electrophysiologic investigation revealed signs of polyneuropathy in 18 patients initially and in 11 patients 2-3 months later. CONCLUSION: In our patient population the frequency of the development of polyneuropathy was high (81.8%). Electrophysiologic investigation is superior to clinical neurologic examination in the detection of polyneuropathies.

Successful treatment of severe myocardial failure after postpartum haemorrhage with the use of an intra-aortic balloon pump.

We report a 29-year-old primigravid who developed cardiac failure following postpartum haemorrhage unresponsive to volume resuscitation and therapy with catecholamines and phosphodiesterase-inhibitors. Transoesophageal echocardiography (TEE) demonstrated left atrial and ventricular dilatation and global left ventricular hypokinesis. No elevation of serum MB-isoenzyme fraction was detected and other organ functions remained stable. Although emergency cardiac transplantation was considered in the presented patient, the institution of intra-aortic counterpulsation was decided on as a first treatment option. Intra-aortic balloon counter-pulsation rapidly improved cardiac function and led to weaning from pharmacological cardiac support within a few days. Mechanical circulatory assist devices can be life-saving in postpartum-haemorrhage-associated cardiac failure.

[Polyneuropathy in the critically ill patient--critical illness polyneuropathy]. / Die Polyneuropathie des kritisch kranken Patienten--critical illness polyneuropathy.

Polyneuropathy developing in critically ill patients ("critical illness polyneuropathy"--CIP) is diagnosed with increasing frequency in intensive care units. CIP is an axonal polyneuropathy leading to difficulties in weaning from artificial ventilation and symmetrical flaccid tetraparesis. Pathogenetically CIP is considered to be part of the multiple organ dysfunction syndrome (MODS) in the course of sepsis or systemic inflammatory response syndrome (SIRS). The incidence of CIP in septic patients with MODS ranges from 50% to 70%. Electroneurography (ENG) and electromyography (EMG) are essential diagnostic procedures. The mortality in patients with CIP is higher than in patients without CIP. Depending on the severity of CIP, recovery of neurological function in survivors is usually relatively good.

[Anaesthesia for cardiac catheterization in children]. / Anästhesie für Herzkatheteruntersuchungen bei Kindern.

Cardiac catheterization in children with congenital heart disease or in adults with completely or partially corrected cardiac defects, is a growing field of activity for anaesthesiologists. This requires not only the willingness for interdisciplinary co-operation, but also detailed knowledge about the pathophysiology of congenital heart diseases. In interventional paediatric cardiology significant innovations have occurred during recent years including stenting of a patent ductus arteriosus and of peripheral pulmonary artery stenosis. Furthermore, radiofrequency catheter ablation for recurrent tachyarrhythmia, or resynchronisation therapy with biventricular pacing in the setting of congestive heart failure, or implantation of cardioverter defibrillators are increasingly being employed which require anaesthesia support.

Electromechanical synchronization of the heterotopic and native heart by dual atrial stimulation following heart transplantation.

After heterotopic heart transplantation, a 59-year-old woman presented with remarkable symptoms of breathlessness and fatigue, despite excellent donor heart function. Asynchrony of donor and native heart provoked haemodynamic instability. Dual atrial pacemaker implantation lead to linkage and synchronization of atrial and ventricular contraction in both the donor and native heart with the faster organ executing the synchronization. Remarkable relief of symptoms has been evident during the long-term follow-up.

Effects of protamine and heparin can be detected and easily differentiated by modified thrombelastography (Rotem): an in vitro study.

BACKGROUND: Precise coagulation monitoring might help prevent heparin-protamine mismatch and thus decrease postoperative blood loss. We therefore measured coagulation time (CT) by modified thrombelastography (Rotem) as a possible differential monitor of the effects of heparin and protamine. METHODS: Undiluted and diluted blood samples from 26 healthy volunteers were spiked with increasing concentrations of heparin (0.1, 0.2, 0.4, 0.8 and 1 U ml(-1)). In addition, undiluted blood was spiked with protamine hydrochloride (0.1, 0.2, 0.4, 0.8 and 1.6 U ml(-1)), and we tested the effect of protamine on the reversal of heparin 0.4 U ml(-1). Heparin-containing samples were analysed using the heparin-sensitive INTEM test and the heparinase-containing HEPTEM test; protamine series were also analysed with the EXTEM test (tissue factor activation). RESULTS: CT by the INTEM test [CT-INTEM; median (min/max)] increased significantly and dose-dependently with increasing concentrations of heparin [control, 175 s (146/226); heparin, 1.0 U ml(-1) 1320 s (559/2100); P<0.001] and protamine [control, 172 s (150/255); protamine, 1.6 U ml(-1) 527 s (300/1345); P<0.0001]. Up to heparin concentrations of 0.4 U ml(-1), results were similar in undiluted and diluted blood samples. As expected, CT-HEPTEM remained within the normal range for all tested heparin concentrations (median 180-183 s), but increased similarly to CT-INTEM for increasing protamine concentrations. CONCLUSION: CT measurement using the Rotem technique appears to be a valuable tool for heparin-protamine management. For detection of heparin alone, protamine alone and the two combined, the ratio of CT-INTEM:CT-HEPTEM can be used to distinguish the effects of heparin excess (CT-INTEM:CT-HEPTEM>1) from those of protamine excess (CT-INTEM:CT-HEPTEM=1).

A pilot study of left tracheal pulse oximetry.

We tested the hypothesis that left tracheal pulse oximetry (SpO(2)) is more accurate than finger SpO(2) when compared with oxygen saturation from arterial blood samples (SaO(2)) in anesthetized patients with normal thoracic anatomy. We also tested the hypothesis that tracheal oximetry readings are primarily derived from the tracheal mucosa. We studied 20 hemodynamically stable, well oxygenated, anesthetized patients with normal anatomy (ASA physical status I-III, 18-80 yr old). A single-use pediatric pulse oximeter was attached to the left lateral surface of a tracheal tube cuff. Tracheal and finger SpO(2) (dominant index finger), and SaO(2) (nondominant radial artery) were taken with the intracuff pressure at 0-60 cm H(2)O. Tracheal SpO(2) was the same as SaO(2) at an intracuff pressure of 10-60 cm H(2)O, but was less when the intracuff pressure was zero (P<0.0001). Tracheal SpO(2) was higher than finger SpO(2) at an intracuff pressure of 10-60 cm H(2)O (all: P <0.001), but was lower when the intracuff pressure was zero (P< 0.0001). SaO(2) was always higher than finger SaO(2) (P<0.0001). Tracheal SpO(2) was lower at an intracuff pressure of zero (P< 0.0001), but was otherwise similar over the range of intracuff pressures. SaO(2) and finger SpO(2) did not vary with intracuff pressure. Tracheal SpO(2) agrees more closely with SaO(2) than finger SpO(2) at an intracuff pressure of 10-60 cm H(2)O (mean difference < 0.2%). We conclude that left tracheal SpO(2) is feasible and provides similar readings to arterial blood samples and more accurate readings than finger oximetry in hemodynamically stable, well oxygenated, anesthetized patients with normal thoracic anatomy. Tracheal oximetry readings are not primarily derived from the tracheal mucosa. The technique merits further evaluation.

The feasibility of transesophageal echocardiograph-guided right and left ventricular oximetry in hemodynamically stable patients undergoing coronary artery bypass grafting.

UNLABELLED: There are no techniques available for continuous noninvasive measurement of the oxygen saturation of blood flowing through the heart. We assessed the feasibility and accuracy of transesophageal echocardiograph (TEE)-guided left ventricular (SpO2 LV) and right ventricular (SpO2 RV) oximetry. Twenty hemodynamically stable, well-oxygenated anesthetized patients (ASA physical status III, aged 51-75 yr) undergoing coronary artery bypass grafting were studied. A TEE probe was modified by attaching a single-use pediatric reflectance pulse oximeter just proximal to the ultrasound transducer. The TEE probe was directed toward the LV by using the transgastric mid-short axis view or toward the RV by using the transgastric RV inflow view, in random order. Readings were taken every 30 s for 10 min during a hemodynamically stable period of anesthesia. Simultaneous blood samples were taken from the radial artery and pulmonary artery to determine arterial oxygen saturation (SaO2) and mixed venous oxygen saturation (SvO2), respectively. During SpO2 LV readings, simultaneous finger pulse oximetry (SpO2 finger) was also recorded. SpO2 LV was feasible in 20 of 20 patients, and SpO2 RV was feasible in 19 of 20 patients. The mean +/- SD (range) oxygen saturation for each method was the following: SpO2 LV, 98.7% +/- 0.6% (97%-100%); SaO2, 98.7% +/- 0.6% (96.6%-99.4%); SpO2 finger, 98.1% +/- 1.2% (97%-100%); SpO2 RV, 73.9% +/- 4.7% (64%-85%); and SvO2, 74.5% +/- 4.4% (66.8%-82.6%). SpO2 LV agreed closely with SaO2 (mean difference, 0.072%). SpO2 RV agreed closely with SvO2 (mean difference, 0.65%). SpO2 LV agreed more closely with SaO2 than finger oximetry (mean difference, -0.072 vs -0.692). TEE-guided SpO2 LV and SpO2 RV are feasible in hemodynamically stable anesthetized patients and provide similar readings to arterial and mixed venous blood samples. The technique merits further investigation. IMPLICATIONS: Transesophageal echocardiograph-guided left and right ventricular oximetry is feasible in hemodynamically stable anesthetized patients and provides similar readings to arterial and mixed venous blood samples.

A pilot study of pharyngeal pulse oximetry with the laryngeal mask airway: a comparison with finger oximetry and arterial saturation measurements in healthy anesthetized patients.

UNLABELLED: We compared pharyngeal SpO(2) by using the laryngeal mask airway (LMA) to finger SpO(2) and oxygen saturation from arterial blood samples (SaO(2)). We studied 20 hemodynamically stable, well oxygenated, anesthetized patients (ASA physical status I-III, aged 18-80 yr). A single-use pediatric pulse oximeter was attached to the back plate of a size 5 LMA. Pharyngeal and finger SpO(2) (dominant index finger) and SaO(2) (nondominant radial artery) were measured with the cuff volume at 0-40 mL in the neutral position. The intracuff pressure was then set at 60 cm H(2)O in the neutral position, and readings were taken with the head-neck flexed, extended, and rotated. SaO(2) was the same as pharyngeal SpO(2) at 20 and 30 mL cuff volume, but higher than pharyngeal SpO(2) at all other cuff volumes and head-neck positions (P < 0.04). SaO(2) was always higher than finger SpO(2) (P < 0.01). Pharyngeal SpO(2) was higher than finger SpO(2) at cuff volumes 10-40 mL and in the flexed and rotated head-neck positions (all: P < 0.007), but was lower at 0 cuff volume (P < 0.0001) and similar in the extended head-neck position. There was an increase in pharyngeal SpO(2) between 0 and 10 mL cuff volume (P < 0.0001), but no changes thereafter. Pharyngeal SpO(2) was similar in the flexed, rotated and extended head-neck positions. Pharyngeal SpO(2) agrees more closely with SaO(2) (mean difference < 0.7%) than finger SpO(2) (mean difference > 1.1%) at 10-40 mL cuff volume and in head-neck flexion. The standard error of limits was identical (0.09) for both finger SpO(2) and pharyngeal SpO(2) if data at 0 cuff volume are excluded. We conclude that pharyngeal SpO(2) with the LMA is feasible and generally provides more accurate readings than finger SpO(2) in hemodynamically stable, well oxygenated, anesthetized patients. IMPLICATIONS: Pharyngeal oximetry with the laryngeal mask airway is feasible and generally provides more accurate readings than finger oximetry in hemodynamically stable, well oxygenated, anesthetized patients.

Continuous positive airway pressure at 10 cm H(2)O during cardiopulmonary bypass improves postoperative gas exchange.

UNLABELLED: Postbypass pulmonary dysfunction including atelectasis and increased shunting is a common problem in the intensive care unit. Negative net fluid balance and continuous positive airway pressure (CPAP) have been used to reduce the adverse effects of cardiopulmonary bypass (CPB) on the lung. To determine whether CPAP at 10 cm H(2)O during CPB results in improved postoperative gas exchange in comparison with deflated lungs during CPB, we examined 14 patients scheduled for elective cardiac surgery. Seven patients received CPAP at 10 cm H(2)O during CPB, and in the other seven patients, the lungs were open to the atmosphere (control). Measurements were taken before and after CPB, after thoracic closure, and 4 h after CPB in the intensive care unit. CPAP at 10 cm H(2)O resulted in significantly more perfusion of lung areas with a normal ventilation/perfusion distribution (V(A)/Q) and significantly less shunt and low V(A)/Q perfusion 4 h after CPB in comparison with the control group. Consequently, arterial oxygen partial pressure was significantly higher and alveolar-arterial oxygen partial pressure difference was significantly smaller. We conclude that CPAP at 10 cm H(2)O during CPB is a simple maneuver that improves postoperative gas exchange. IMPLICATIONS: Inflation of the lungs at a pressure of 10 cm H(2)O as compared with leaving the lungs deflated during cardiopulmonary bypass was examined. Lung inflation during bypass resulted in significantly improved postoperative gas exchange.

[Cytomegalovirus infection after heart transplantation. Retrospective analysis of an antiviral CMV prevention]. / Cytomegalievirus-Infektion nach Herztransplantation. Retrospektive Analyse einer antiviralen CMV-Prophylaxe.

OBJECTIVE: Cytomegalovirus (CMV) infection is the most common viral infection in the early period after heart transplantation (HTX) and causes a significant morbidity and mortality. Although controversial, CMV is related to acute and chronic allograft rejection and to the development of graft vascular disease. It therefore plays an important role in the long-time outcome after solid organ transplantation. PATIENTS AND METHODS: 45 patients received a new heart between 1.1.97 and 31.12.1998. All of them were enrolled postoperatively in three-month antiviral prophylaxis (Cymevene). Only those patients were excluded from prophylaxis who were seronegative for CMV and received hearts from seronegative donors (n = 6). The pp65 antigenaemia assay and the murex hybrid capture CMV DNA assay on peripheral blood as well as the early antigen detection in the urine were used for CMV detection and also for monitoring. RESULTS: A total number of 580 assays were analysed (12.9 assays/patient). 561 tests (96.7%) were negative, 19 (3.3%) were positive. For CMV testing the pp65 antigenemia assay was used in 64.1%, the murex hybrid capture CMV DNA assay in 18.4% and the urine early antigen detection in 17.4%. Three patients (6.7%) developed viraemia during the first 3 postoperative months. Two patients (4.4%) suffered from CMV infection 8 and 9 months after heart transplantation and had to be treated with antiviral agents. Three patients (6.7%) died early after transplantation, but none had a CMV infection. CONCLUSION: Prevention of CMV disease was successful with three months of antiviral CMV prophylaxis after HTX. Asymptomatic viraemia during the prophylaxis period did not lead to tissue invasive disease. It is possible to carry out rapid CMV detection and CMV monitoring with the commercially available antigenaemia assays.

Effects of a leucocyte depleting arterial line filter on perioperative proteolytic enzyme and oxygen free radical release in patients undergoing aortocoronary bypass surgery.

BACKGROUND: Proteolytic enzymes and oxygen free radicals released from activated leucocytes contribute significantly to the organ dysfunction associated with cardiopulmonary bypass. Leucocyte depletion during extracorporeal circulation should reduce the release of these toxic compounds and thereby improve postbypass myocardial and pulmonary function. Recently, a leucocyte-specific arterial line filter to achieve leucocyte depletion during clinical perfusion has become commercially available. The aim of this study, therefore, was to evaluate the influence of the leucocyte depleting arterial line filter on proteolytic enzyme release, oxygen free radical release and postbypass pulmonary and myocardial function in patients undergoing bypass surgery. METHODS: Forty patients undergoing elective aortocoronary bypass surgery were included into this prospective, randomized clinical study, 20 in the leucocyte depletion (LG-6 group, leucocyte-specific arterial line filter) and 20 in the control group (AV-6 group, standard arterial line filter). White cell count, differential white cell count, plasma elastase concentration, plasma malondialdehyde concentration and C-reactive protein were determined before, twice during and immediately after cardiopulmonary bypass, at the end of surgery and 6 and 20 h thereafter. RESULTS: White cell count, differential white cell count, malondialdehyde and C-reactive protein were not significantly different between LG-6 and control patients. Plasma elastase concentrations were significantly (P < or = 0.03) higher during and immediately after extracorporeal circulation in LG-6 group patients. Need for inotropic support, arterial pO2 after extracorporeal circulation and perioperative CK MB mass and troponin I release were not different between the two groups of patients. CONCLUSION: The use of a leucocyte depleting arterial line filter is associated with an increased release of the proteolytic enzyme elastase, but does not reliably and consistently achieve effective leucocyte depletion during clinical perfusion. In contrast to previous studies, we could not demonstrate any significant difference in postbypass pulmonary or myocardial function between patients perfused with the leucocyte-specific arterial line filter and control patients. Our data do not support the routine use of a leucocyte depleting arterial line filter during clinical perfusion in patients undergoing elective aortocoronary bypass surgery.

[Comparative study of propofol emulsions for anesthesia in varicose vein operations]. / Vergleichende Untersuchung zweier Propofol-Emulsionen zur Anästhesie bei Varizenoperationen.

PURPOSE: It is commonly known that propofol-based anaesthesia is easily controlled and well tolerated. These advantages of propofol are partly offset by the comparably high costs of the anaesthetic. The present prospective randomised double-blind cross-over study compared two propofol emulsions with regard to their efficacy and drug safety. METHODS: 30 patients were included in this study. All patients underwent two propofol-based anaesthesias for leg vein surgery on both legs within 2-4 days. The patients were randomised in two treatment groups where Group A (n = 15) received the investigational drug for the 2nd anaesthesia and the control drug for the 1st anaesthesia. The order of drug application was reversed for Group B (n = 15). The propofol induction doses, the maintenance doses, and the side effect profiles were evaluated for the purpose of comparing the two propofol emulsions. RESULTS: The study showed no differences in the efficacy of the two propofol emulsions. Furthermore, the side effect profiles were almost identical and did not reveal any unknown side effects of propofol. CONCLUSIONS: The results clearly demonstrate that both propofol emulsions are comparably well suited for vascular surgery anaesthesia. This study demonstrates a methodological clinical approach to compare the same medication supplied by different manufacturers.

The impact of business cards on physician recognition after general anesthesia.

UNLABELLED: Despite their contribution to overall perioperative treatment of patients, anesthesiologists often remain in anonymity. We evaluated the impact of business cards on physician recognition after general anesthesia. Using a questionnaire, 441 patients were interviewed for recall of the anesthesiologist's name, the surgeon's name, and their overall satisfaction with anesthetic care 6 wk after undergoing surgery during general anesthesia. Of these patients, 155 had and 137 had not randomly received a business card during the preoperative visit, with another 149 patients serving as a control group. Business card recipients responded significantly more frequently than did nonrecipients or patients from the control group (65.8% vs 54.7% vs 53%), with recall of the anesthesiologist's name being significantly more frequent in the Business Card Recipient group (51.5% vs 14.3% vs 11.4%). Patient satisfaction with anesthetic care and recall of the surgeon's name were similar in all groups. The use of a simple tool such as a business card can indeed produce a measurable positive change in physician recognition on the part of the patient. IMPLICATIONS: Anesthesiologists often remain anonymous in everyday clinical practice. Handing a business card to the patient during the preoperative visit increased the postoperative recall of the anesthesiologist's name from 11% to 51%.

Exogenous neopterin causes cardiac contractile dysfunction in the isolated perfused rat heart.

Neopterin is known in humans as a sensitive marker for diseases associated with increased activity of the cellular immune system. Recent studies report neopterin also to exhibit distinct effects: neopterin induces inducible nitric oxide synthase expression in rat vascular smooth muscle cells and activates translocation of nuclear factor- kappa B. Neopterin may also induce oxidative stress causing apoptotic cell death, or superinduce tumor necrosis factor- alpha -mediated apoptosis. Observing these effects in cell cultures, we were interested in possible consequences of neopterin on cardiac function in the isolated perfused rat heart. The influence of neopterin in three different concentrations (10 micromol/l, 50 micromol/l, 100 micromol/l) on cardiac contractility parameters and coronary vascular resistance were studied in 67 male Sprague-Dawley rats using the temperature-controlled and pressure-constant Langendorff apparatus with retrograde perfusion of the aorta with a Krebs-Henseleit buffer. Treatment with 100 micromol/l neopterin resulted in a significant decrease in coronary flow and cardiac contractility. Coronary flow decreased from 15.2 to 9.5 ml/min (P=0.002), left ventricular pressure from 80 to 52 mmHg (P=0. 002), rate of pressure fall from 1605 to 923 mmHg/s (P=0.001) and rate of pressure rise from 2862 to 1709 mmHg/s (P=0.001). Concentrations lower than 100 micromol/l neopterin had no significant effect on cardiac function. Our study demonstrates a considerable influence of exogenous neopterin on cardiac performance in the Langendorff model of isolated perfused rat hearts. This has to be considered a potential pathogenic factor of cardiac disturbances in diseases in which high concentrations of neopterin are released due to immune activation. At present the exact mechanism remains unclear.