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Biomedical subjects

Anton J M Wagenmakers

Publications and source records attributed to Anton J M Wagenmakers.

At least 19 recordsLinked to original sources
PubMed2007

Preferential uptake of dietary Fatty acids in adipose tissue and muscle in the postprandial period.

Despite consistent evidence that abnormalities of fatty acid delivery and storage underlie the metabolic defects of insulin resistance, physiological pathways by which fat is stored in adipose tissue and skeletal muscle are not clear. We used a combination of stable isotope labeling and arteriovenous difference measurements to elucidate pathways of postprandial fat deposition in adipose tissue and skeletal muscle in healthy humans. A test meal containing [U-(13)C]palmitate was combined with intravenous infusion of [(2)H(2)]palmitate to label plasma fatty acids and VLDL-triglyceride. Both dietary (chylomicron) and VLDL-triglyceride were cleared across adipose tissue and muscle, though with greater fractional extraction of the chylomicron-triglyceride. In adipose tissue there was significant uptake of plasma nonesterified fatty acids (NEFAs) in the postprandial but not the fasting state. However, this was minor in comparison with chylomicron-triglyceride fatty acids. We modeled the fate of fatty acids released by lipoprotein lipase (LPL). There was clear preferential uptake of these fatty acids compared with plasma NEFAs. In muscle, there was unexpected evidence for release of LPL-derived fatty acids into the plasma. With this integrative physiological approach, we have revealed hidden complexities in pathways of fatty acid uptake in adipose tissue and skeletal muscle.

Abdomen↗
PubMed2006

Age-related morphological changes in skeletal muscle cells of acid alpha-glucosidase knockout mice.

Glycogen storage disease type II (GSDII), caused by a genetic defect in acid alpha-glucosidase (AGLU), leads to a decline in muscle contractility caused by both muscle wasting and a decrease in muscle quality, i.e., force generated per unit muscle mass. A previous study has shown that loss of muscle mass can only explain one-third of the decrease in contractile performance. Here we report on changes in the intramyocellular structural organization in a mouse knockout model (AGLU(-/-) mice) as a possible cause for the decline in muscle quality. Swollen, glycogen-filled lysosomes and centrally localized cores with cellular debris partially contribute to the decline in muscle quality. Altered localization and deposition of cytoskeletal proteins desmin and titin may reflect adaptive mechanisms at the age of 13 months, but a decline in quality at 20 months of age. The early deposition of lipofuscin in AGLU-deficient myocytes (13 months) is most likely a reflection of enhanced oxidative stress, which may also affect muscle quality. These collective findings, on the one hand, may explain the decrease in tissue quality and, on the other, may represent markers for efficacy of therapeutic interventions to restore muscle function in patients suffering from GSDII.

Aging↗
PubMed2006

Integration of the metabolic and cardiovascular effects of exercise.

Most of the essays in this volume have adopted a reductionist approach and have focused on the biochemistry either in skeletal muscle or in the vascular wall. There is however a complex interaction between the biochemistry in the endothelium of the microvascular wall, the vascular smooth muscle and the skeletal muscle fibres involving signalling pathways in the three tissues and an intense exchange of signal molecules between them. In the present essay an integrative overview is given of this complex metabolic interaction and the impairments in it that lead to type 2 diabetes and cardiovascular disease.A reduced nitric oxide production by the (micro)vascular endothelium is identified as the key event and is reversible by regular exercise and a reduced calorie intake. The chapter also contains a description of the complex metabolic network controlled by the inducible transcription factor nuclear factor-kappaB, that is activated in more advanced stages of the chronic diseases, and either leads to repair of the microvascular wall or to irreversible damage and the severe complications of end stage cardiovascular disease and type 2 diabetes.

Atherosclerosis↗
PubMed2006

Co-ingestion of protein and leucine stimulates muscle protein synthesis rates to the same extent in young and elderly lean men.

BACKGROUND: The progressive loss of skeletal muscle mass with aging is attributed to a disruption in the regulation of skeletal muscle protein turnover. OBJECTIVE: We investigated the effects on whole-body protein balance and mixed-muscle protein synthesis rates of the ingestion of carbohydrate with or without protein and free leucine after simulated activities of daily living. DESIGN: Eight elderly (75 +/- 1 y) and 8 young (20 +/- 1 y) lean men were randomly assigned to 2 crossover experiments in which they consumed either carbohydrate (CHO) or carbohydrate plus protein and free leucine (CHO+Pro+Leu) after performing 30 min of standardized activities of daily living. Primed, continuous infusions with L-[ring-13C6]phenylalanine and L-[ring-2H2]tyrosine were applied, and blood and muscle samples were collected to assess whole-body protein turnover and the protein fractional synthetic rate in the vastus lateralis muscle over a 6-h period. RESULTS: Whole-body phenylalanine and tyrosine flux were significantly higher in the young than in the elderly men (P < 0.01). Protein balance was negative in the CHO experiment but positive in the CHO+Pro+Leu experiment in both groups. Mixed-muscle protein synthesis rates were significantly greater in the CHO+Pro+Leu than in the CHO experiment in both the young (0.082 +/- 0.005%/h and 0.060 +/- 0.005%/h, respectively; P < 0.01) and the elderly (0.072 +/- 0.006%/h and 0.043 +/- 0.003%/h, respectively; P < 0.01) subjects, with no significant differences between groups. CONCLUSIONS: Co-ingestion of protein and leucine with carbohydrate after activities of daily living improves whole-body protein balance, and the increase in muscle protein synthesis rates is not significantly different between lean young and elderly men.

Activities of Daily Living↗
PubMed2005

Inhibition of adipose tissue lipolysis increases intramuscular lipid and glycogen use in vivo in humans.

This study investigates the consequences of inhibition of adipose tissue lipolysis on skeletal muscle substrate use. Ten subjects were studied at rest and during exercise and subsequent recovery under normal, fasting conditions (control trial, CON) and following administration of a nicotinic acid analog (low plasma free fatty acid trial, LFA). Continuous [U-13C]palmitate and [6,6-2H2]glucose infusions were applied to quantify plasma free fatty acid (FFA) and glucose oxidation rates and to estimate intramuscular triacylglycerol (IMTG) and glycogen use. Muscle biopsies were collected to measure 1) fiber type-specific IMTG content; 2) allosteric regulators of hormone-sensitive lipase (HSL), glycogen phosphorylase, and pyruvate dehydrogenase; and 3) the phosphorylation status of HSL at Ser563 and Ser565. Administration of a nicotinic acid analog (acipimox) substantially reduced plasma FFA rate of appearance and subsequent plasma FFA concentrations (P < 0.0001). At rest, this substantially reduced plasma FFA oxidation rates, which was compensated by an increase in the estimated IMTG use (P < 0.05). During exercise, the progressive increase in FFA rate of appearance, uptake, and oxidation was prevented in the LFA trial and matched by greater IMTG and glycogen use. Differential phosphorylation of HSL or relief of its allosteric inhibition by long-chain fatty acyl-CoA could not explain the increase in muscle TG use, but there was evidence to support the contention that regulation may reside at the level of the glucose-fatty acid cycle. This study confirms the hypothesis that plasma FFA availability regulates both intramuscular lipid and glycogen use in vivo in humans.

Adipose Tissue↗
PubMed2005

Age-related decline in muscle strength and power output in acid 1-4 alpha-glucosidase knockout mice.

A hallmark of glycogen storage disease type II, caused by defective alpha-glucosidase (AGLU) activity, is a progressive decline in muscle performance. The objective of this study was to determine the relative contribution to this decline in muscle performance of (1) decline in muscle mass; (2) decline in muscle protein content per unit mass; and (3) accumulation of glycogen. To this end, isometric torque and power in AGLU(-/-) mice at 7, 13, and 20 months were assessed in situ. Power (approximately 24 mW) and torque (approximately 2.45 Nmm) did not change with age in control animals, but declined significantly in AGLU(-/-) mice, in the three age groups. No decline in protein content per unit muscle mass was observed. Muscle atrophy explained one third of the decline in muscle performance; the remaining part was attributed to a decrease in muscle quality--a decrease in mechanical performance per unit muscle mass. Mechanical effects of glycogen inclusions could not fully explain this decrease. Additional factors must therefore play a role.

Aging↗
PubMed2005

Co-ingestion of a protein hydrolysate and amino acid mixture with carbohydrate improves plasma glucose disposal in patients with type 2 diabetes.

BACKGROUND: Although insulin secretion after carbohydrate ingestion is severely impaired in patients with type 2 diabetes, amino acid and protein co-ingestion can substantially increase plasma insulin responses. OBJECTIVE: We investigated insulin responses and the subsequent plasma glucose disposal rates after the ingestion of carbohydrate alone (CHO) or with a protein hydrolysate and amino acid mixture (CHO+PRO) in patients with a long-term diagnosis of type 2 diabetes. DESIGN: Ten type 2 diabetic patients [mean (+/-SEM) age: 62 +/- 2 y; body mass index (kg/m(2)): 27 +/- 1] and 9 healthy control subjects (age: 58 +/- 1 y; body mass index: 27 +/- 1) participated in 2 trials in which the plasma insulin response was measured after the ingestion of 0.7 g carbohydrate . kg(-1) . h(-1) with or without 0.35 g . kg(-1) . h(-1) of a mixture that contained a protein hydrolysate, leucine, and phenylalanine. Continuous infusions with [6,6-(2)H(2)]glucose were then given to investigate plasma glucose disposal. RESULTS: Plasma insulin responses were higher by 299 +/- 64% and 132 +/- 63% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The subsequent plasma glucose responses were reduced by 28 +/- 6% and 33 +/- 3% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The reduced plasma glucose response in the diabetic patients was attributed to a 13 +/- 3% increase in glucose disposal (P < 0.01). CONCLUSIONS: The combined ingestion of carbohydrate with a protein hydrolysate and amino acid mixture significantly increases de novo insulin production in patients with a long-term diagnosis of type 2 diabetes. The increased insulin response stimulates plasma glucose disposal and reduces postprandial glucose concentrations.

Blood Glucose↗
PubMed2004

Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects.

The present study was designed to determine postexercise muscle protein synthesis and whole body protein balance following the combined ingestion of carbohydrate with or without protein and/or free leucine. Eight male subjects were randomly assigned to three trials in which they consumed drinks containing either carbohydrate (CHO), carbohydrate and protein (CHO+PRO), or carbohydrate, protein, and free leucine (CHO+PRO+Leu) following 45 min of resistance exercise. A primed, continuous infusion of L-[ring-13C6]phenylalanine was applied, with blood samples and muscle biopsies collected to assess fractional synthetic rate (FSR) in the vastus lateralis muscle as well as whole body protein turnover during 6 h of postexercise recovery. Plasma insulin response was higher in the CHO+PRO+Leu compared with the CHO and CHO+PRO trials (+240 +/- 19% and +77 +/- 11%, respectively, P < 0.05). Whole body protein breakdown rates were lower, and whole body protein synthesis rates were higher, in the CHO+PRO and CHO+PRO+Leu trials compared with the CHO trial (P < 0.05). Addition of leucine in the CHO+PRO+Leu trial resulted in a lower protein oxidation rate compared with the CHO+PRO trial. Protein balance was negative during recovery in the CHO trial but positive in the CHO+PRO and CHO+PRO+Leu trials. In the CHO+PRO+Leu trial, whole body net protein balance was significantly greater compared with values observed in the CHO+PRO and CHO trials (P < 0.05). Mixed muscle FSR, measured over a 6-h period of postexercise recovery, was significantly greater in the CHO+PRO+Leu trial compared with the CHO trial (0.095 +/- 0.006 vs. 0.061 +/- 0.008%/h, respectively, P < 0.05), with intermediate values observed in the CHO+PRO trial (0.0820 +/- 0.0104%/h). We conclude that coingestion of protein and leucine stimulates muscle protein synthesis and optimizes whole body protein balance compared with the intake of carbohydrate only.

Adult↗
PubMed2004

Combined ingestion of protein and carbohydrate improves protein balance during ultra-endurance exercise.

The aims of this study were to compare different tracer methods to assess whole body protein turnover during 6 h of prolonged endurance exercise when carbohydrate was ingested throughout the exercise period and to investigate whether addition of protein can improve protein balance. Eight endurance-trained athletes were studied on two different occasions at rest (4 h), during 6 h of exercise at 50% of maximal O2 uptake (in sequential order: 2.5 h of cycling, 1 h of running, and 2.5 h of cycling), and during subsequent recovery (4 h). Subjects ingested carbohydrate (CHO trial; 0.7 g CHO.kg(-1.)h(-1)) or carbohydrate/protein beverages (CHO + PRO trial; 0.7 g CHO.kg(-1).h(-1) and 0.25 g PRO.kg(-1).h(-1)) at 30-min intervals during the entire study. Whole body protein metabolism was determined by infusion of L-[1-13C]leucine, L-[2H5]phenylalanine, and [15N2]urea tracers with sampling of blood and expired breath. Leucine oxidation increased from rest to exercise [27 +/- 2.5 vs. 74 +/- 8.8 (CHO) and 85 +/- 9.5 vs. 200 +/- 16.3 mg protein.kg(-1).h(-1) (CHO + PRO), P < 0.05], whereas phenylalanine oxidation and urea production did not increase with exercise. Whole body protein balance during exercise with carbohydrate ingestion was negative (-74 +/- 8.8, -17 +/- 1.1, and -72 +/- 5.7 mg protein.kg(-1).h(-1)) when L-[1-13C]leucine, L-[2H5]phenylalanine, and [15N2]urea, respectively, were used as tracers. Addition of protein to the carbohydrate drinks resulted in a positive or less-negative protein balance (-32 +/- 16.3, 165 +/- 4.6, and 151 +/- 13.4 mg protein.kg(-1).h(-1)) when L-[1-13C]leucine, L-[2H5]phenylalanine, and [15N2]urea, respectively, were used as tracers. We conclude that, even during 6 h of exhaustive exercise in trained athletes using carbohydrate supplements, net protein oxidation does not increase compared with the resting state and/or postexercise recovery. Combined ingestion of protein and carbohydrate improves net protein balance at rest as well as during exercise and postexercise recovery.

Adult↗
PubMed2004

Creatine supplementation increases glycogen storage but not GLUT-4 expression in human skeletal muscle.

It has been speculated that creatine supplementation affects muscle glucose metabolism in humans by increasing muscle glycogen storage and up-regulating GLUT-4 protein expression. In the present study, we assessed the effects of creatine loading and prolonged supplementation on muscle glycogen storage and GLUT-4 mRNA and protein content in humans. A total of 20 subjects participated in a 6-week supplementation period during which creatine or a placebo was ingested. Muscle biopsies were taken before and after 5 days of creatine loading (20 g.day(-1)) and after 6 weeks of continued supplementation (2 g.day(-1)). Fasting plasma insulin concentrations, muscle creatine, glycogen and GLUT-4 protein content as well as GLUT-4, glycogen synthase-1 (GS-1) and glycogenin-1 (Gln-1) mRNA expression were determined. Creatine loading significantly increased total creatine, free creatine and creatine phosphate content with a concomitant 18 +/- 5% increase in muscle glycogen content (P<0.05). The subsequent use of a 2 g.day(-1) maintenance dose for 37 days did not maintain total creatine, creatine phosphate and glycogen content at the elevated levels. The initial increase in muscle glycogen accumulation could not be explained by an increase in fasting plasma insulin concentration, muscle GLUT-4 mRNA and/or protein content. In addition, neither muscle GS-1 nor Gln-1 mRNA expression was affected. We conclude that creatine ingestion itself stimulates muscle glycogen storage, but does not affect muscle GLUT-4 expression.

Adenosine Triphosphate↗
PubMed2003

Intramyocellular lipids form an important substrate source during moderate intensity exercise in endurance-trained males in a fasted state.

Both stable isotope methodology and fluorescence microscopy were applied to define the use of intramuscular triglyceride (IMTG) stores as a substrate source during exercise on a whole-body as well as on a fibre type-specific intramyocellular level in trained male cyclists. Following an overnight fast, eight subjects were studied at rest, during 120 min of moderate intensity exercise (60 % maximal oxygen uptake capacity (VO2,max)) and 120 min of post-exercise recovery. Continuous infusions of [U-13C]palmitate and [6,6-2H2]glucose were administered at rest and during subsequent exercise to quantify whole-body plasma free fatty acid (FFA) and glucose oxidation rates and the contribution of other fat sources (sum of muscle- plus lipoprotein-derived TG) and muscle glycogen to total energy expenditure. Fibre type-specific intramyocellular lipid content was determined in muscle biopsy samples collected before, immediately after and 2 h after exercise. At rest, fat oxidation provided 66 +/- 5 % of total energy expenditure, with FFA and other fat sources contributing 48 +/- 6 and 17 +/- 3 %, respectively. FFA oxidation rates increased during exercise, and correlated well with the change in plasma FFA concentrations. Both the use of other fat sources and muscle glycogen declined with the duration of exercise, whereas plasma glucose production and utilisation increased (P < 0.001). On average, FFA, other fat sources, plasma glucose and muscle glycogen contributed 28 +/- 3, 15 +/- 2, 12 +/- 1 and 45 +/- 4 % to total energy expenditure during exercise, respectively. Fluorescence microscopy revealed a 62 +/- 7 % net decline in muscle lipid content following exercise in the type I fibres only, with no subsequent change during recovery. We conclude that IMTG stores form an important substrate source during moderate intensity exercise in endurance-trained male athletes following an overnight fast, with the oxidation rate of muscle- plus lipoprotein-derived TG being decreased with the duration of exercise.

Acetates↗
PubMed2003

Influence of prolonged endurance cycling and recovery diet on intramuscular triglyceride content in trained males.

Intramuscular triglycerides (IMTG) are assumed to form an important substrate source during prolonged endurance exercise in trained males. This study investigated the effects of endurance exercise and recovery diet on IMTG content in vastus lateralis muscle. Nine male cyclists were provided with a standardized diet for 3 days, after which they performed a 3-h exercise trial at a 55% maximum workload. Before and immediately after exercise and after 24 and 48 h of recovery, magnetic resonance spectroscopy (MRS) was performed to quantitate IMTG content. Muscle biopsies were taken after 48 h of recovery to determine IMTG content by using quantitative fluorescence microscopy. The entire procedure was performed two times; in one trial, a normal diet containing 39% energy (En%) as fat was provided (NF) and in the other a typical carbohydrate-rich athlete's diet (LF: 24 En% fat) was provided. During exercise, IMTG content decreased by 21.4 +/- 3.1%. During recovery, IMTG content increased significantly in the NF trial only, reaching preexercise levels within 48 h. In accord with MRS, fluorescence microscopy showed significantly higher IMTG content in the NF compared with the LF trial, with differences restricted to the type I muscle fibers (2.1 +/- 0.2 vs. 1.4 +/- 0.2% area lipid staining, respectively). In conclusion, IMTG content in the vastus lateralis muscle declines significantly during prolonged endurance exercise in male cyclists. When a normal diet is used, IMTG contents are subsequently repleted within 48 h of postexercise recovery. In contrast, IMTG repletion is impaired substantially when a typical, carbohydrate-rich athlete's diet is used. Data obtained by quantitative fluorescence microscopy correspond well with MRS results, implying that both are valid methods to quantify IMTG content.

Adult↗
PubMed2003

The use of the [1,2-13C]acetate recovery factor in metabolic research.

To provide guidelines on the correct application of the acetate recovery factor in metabolic research, we investigated the influence of exercise intensity and infusion protocol on [1,2-(13)C]acetate label recovery during exercise. Eight cyclists were studied during [1,2-(13)C]acetate infusion for 1 h at rest followed by three 30-min stages of cycling exercise at a workload of 40, 55 and 75% maximal workload ( W(max)), respectively (protocol 1). Four cyclists were subsequently studied following [1,2-(13)C]acetate infusion in three separate trials while cycling at the same workloads but in the absence of any pre-exercise infusion period (protocol 2). Finally, we observed the cyclists during [1,2-(13)C]acetate infusion at a 40% W(max) workload after 4 h of pre-exercise infusion (protocol 3). Acetate recovery increased from 13.7 (0.4)%, after 1 h of rest, to a plateau value of 75.1 (2), 91.2 (0.7) and 101 (2)% during exercise at 40, 55 and 75% W(max) workloads, respectively. In protocol 2, without prior infusion time, fractional label recovery was substantially lower at each separate workload. In contrast, when applying an extensive pre-exercise infusion period of 4 h, acetate recovery rates were substantially increased compared to the values observed in protocols 1 and 2 during exercise at a 40% W(max) workload. In conclusion, in contrast to resting conditions, acetate recovery reaches a plateau value during exercise. Though this plateau value is repeatedly used to correct for label recovery in various exercise studies, our data clearly show that acetate label recovery during exercise not only depends on the exercise intensity but also on the applied infusion protocol. Therefore, theoretical acetate recovery factors taken from previous literature are not generally applicable.

Acetates↗
PubMed2003

Lysosomal dysfunction in muscle with special reference to glycogen storage disease type II.

The importance of proper lysosomal activity in cell and tissue homeostasis is underlined by "experiments of nature", i.e. genetic defects in one of the at least 40 lysosomal enzymes/proteins present in the human cell. The complete lack of 1-4 alpha-glucosidase (glycogen storage disease type II (GSD II) or Pompe disease) is life-threatening. Patients suffering from GSD II commonly die before the age of 2 years because of cardiorespiratory insufficiency. Striated muscle cells appear to be particularly vulnerable in GSD II. The high cytoplasmic glycogen content in muscle cells most likely gives rise to a high rate of glycogen engulfment by the lysosomes. The polysaccharides become subsequently trapped in these organelles when 1-4 alpha-glucosidase activity is absent. During the course of the disease, muscle wasting occurs. It is hypothesised that the gradual loss of muscle mass is caused by a combination of disuse atrophy and lipofuscine-mediated apoptosis of myocytes. Moreover, we hypothesise that in the remaining skeletal muscle cells, longitudinal transmission of force is hampered by swollen lysosomes, clustering of non-contractile material and focal regions with degraded contractile proteins, which results in muscle weakness.

Animals↗
PubMed2003

Effects of creatine loading and prolonged creatine supplementation on body composition, fuel selection, sprint and endurance performance in humans.

Most research on creatine has focused on short-term creatine loading and its effect on high-intensity performance capacity. Some studies have investigated the effect of prolonged creatine use during strength training. However, studies on the effects of prolonged creatine supplementation are lacking. In the present study, we have assessed the effects of both creatine loading and prolonged supplementation on muscle creatine content, body composition, muscle and whole-body oxidative capacity, substrate utilization during submaximal exercise, and on repeated supramaximal sprint, as well as endurance-type time-trial performance on a cycle ergometer. Twenty subjects ingested creatine or a placebo during a 5-day loading period (20 g.day(-1)) after which supplementation was continued for up to 6 weeks (2 g.day(-1)). Creatine loading increased muscle free creatine, creatine phosphate (CrP) and total creatine content ( P <0.05). The subsequent use of a 2 g.day(-1) maintenance dose, as suggested by an American College of Sports Medicine Roundtable, resulted in a decline in both the elevated CrP and total creatine content and maintenance of the free creatine concentration. Both short- and long-term creatine supplementation improved performance during repeated supramaximal sprints on a cycle ergometer. However, whole-body and muscle oxidative capacity, substrate utilization and time-trial performance were not affected. The increase in body mass following creatine loading was maintained after 6 weeks of continued supplementation and accounted for by a corresponding increase in fat-free mass. This study provides definite evidence that prolonged creatine supplementation in humans does not increase muscle or whole-body oxidative capacity and, as such, does not influence substrate utilization or performance during endurance cycling exercise. In addition, our findings suggest that prolonged creatine ingestion induces an increase in fat-free mass.

Adenosine Triphosphate↗
PubMed2003

Coronary sinus catheter placement: assessment of placement criteria and cardiac complications.

STUDY OBJECTIVES: To evaluate the placement and complications of a coronary sinus (CS) catheter in human subjects. DESIGN: Sixty-two CS catheters inserted in patients scheduled for coronary artery bypass graft surgery (CABG). SETTING: University hospital, anesthesia and cardiothoracic surgery departments. PATIENTS: Sixty-two patients without valvular or concomitant diseases undergoing CABG. INTERVENTIONS: CS fluoroscopy, measurements of CS flow, CS oxygen saturation, and CS distal tip pressure before incision, after incision, 20 min after aortic cross-clamp release (X-off), 50 min after X-off, 2 h after X-off, 4 h after X-off, and 6 h after X-off. RESULTS: In 57 patients (92%), we achieved successful CS catheter placement. In five patients (8%), CS catheter positioning was not possible. Of the 57 CS catheters placed, dislocation occurred during the operation in six patients (11%) and postoperatively in three patients (6%). Cardiac complications of CS catheter placement occurred in nine patients (15%). Four patients (6%) acquired hemopericardium. Three of these patients had a small hematoma in the right ventricle. In two other patients, contrast medium appeared in the right ventricular wall during catheterization. No hemodynamic signs of these complications were detected clinically. Irregular heart rhythm was observed in only three patients. CS blood oxygen saturation ranged from 40 to 60%. CS flow amounted to 3% of cardiac output. Variations in CS flow paralleled changes in cardiac output. CONCLUSIONS: A CS catheter is a useful tool for clinical human cardiac research; however, the placement of a CS catheter can cause minor myocardial damage in > 10% of patients. Importantly, this damage may not be clinically evident, but only observed after thoracotomy. CS oxygen saturation, CS flow, distal tip pressure, and fluoroscopy are reliable tools to assess a safe and correct positioning of the CS catheter.

Adult↗