Transcoronary pacing : Reliability during myocardial ischemia and after implantation of a coronary stent.

BACKGROUND: Transcoronary pacing is a useful therapeutic option for the treatment of unheralded bradycardias in the setting of percutaneous coronary interventions (PCI). OBJECTIVES: In the present study, we investigated the influence of stent implantation and transient myocardial ischemia on the feasibility of transcoronary pacing in a porcine model. METHODS: 7 adult pigs underwent a percutaneous coronary intervention with implantation of a coronary stent under general anaesthesia in an animal catheterization laboratory. Transcoronary pacing was established by using a standard guidewire isolated with an angioplasty balloon positioned in the periphery of the right coronary artery serving as the cathode. As the indifferent anode, a skin patch electrode at the back of the animal was used. The reliability of transcoronary pacing was assessed by measurement of threshold and impedance data and the magnitude of the epicardial electrogram at baseline, after implantation of a coronary stent and finally during myocardial ischemia. RESULTS: Effective transcoronary pacing could be demonstrated in all cases with the standard unipolar transcoronary pacing setup yielding a low pacing threshold at baseline of 1.3 ± 0.8 V with an impedance of 283 ± 67 Ω. Implantation of a coronary stent did not influence the pacing threshold (1.0 ± 0.4 V) and impedance (262 ± 63 Ω). Acute myocardial ischemia lead to a significant but clinically nonrelevant increase of the pacing threshold to 2.0 ± 0.6 V and a drop in pacing impedance (137 ± 39 Ω). CONCLUSIONS: Transcoronary pacing in the animal model is not affected by implantation of a coronary stent in the same vessel used for pacing. Despite a significant increase in pacing threshold, the transcoronary pacing approach is reliable in acute myocardial ischemia during a percutaneous coronary intervention.

Vasopressors for acute myocardial infarction complicated by cardiogenic shock.

Several international evidence-based guidelines reveal the lack of evidence on the treatment of patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) for all recommended therapies. We included 6 studies with 842 eligible patients and one ongoing study. Three different adrenergic agents (norepinephrine, dopamine, epinephrine), vasopressin and the NOS inhibitor tilarginine were compared in 4 different combinations. On the small basis of all available evidence we can state that there is no evidence to use tilarginene, some evidence to avoid dopamine due to increased rates of arrhythmias, but some evidence, which suggests to prefer norepinephrine in comparison to epinephrine as vasopressor.

The double guidewire approach for transcoronary pacing in a porcine model.

BACKGROUND: Transcoronary pacing is used for treatment of unheralded bradycardias in the setting of percutaneous coronary interventions (PCI). OBJECTIVES: In the present study we introduced a new concept - the double guidewire approach - for transcoronary pacing in a porcine model. METHODS: Transcoronary pacing was applied in 16 adult pigs under general anaesthesia in an animal catheterization laboratory. A special guidewire with electrical insulation by PTFE coating except for the distal part of the guidewire was positioned in the periphery of a coronary artery serving as the cathode. As the indifferent anode, an additional standard floppy tip guidewire was advanced into the proximal part of the same coronary vessel. The efficacy of double guidewire transcoronary pacing was assessed by measurement of threshold and impedance data and the magnitude of the epicardial electrogram compared with unipolar transcoronary pacing using a standard cutaneous patch electrode as indifferent anode. RESULTS: Transcoronary pacing was effective in all cases. Pacing thresholds obtained with the double guidewire technique (1.5 ± 0.9 V) were similar to those obtained by standard unipolar transcoronary pacing with a cutaneous patch electrode (1.2 ± 0.7 V) and unipolar transvenous pacing against the same cutaneous patch electrode (1.5 ± 1.0 V). Bipolar transvenous pacing yielded the lowest pacing threshold at 0.8 ± 0.4 V. CONCLUSIONS: Transcoronary pacing in the animal model with the novel "double guidewire approach" is a simple and effective pacing technique with comparable pacing thresholds obtained by standard unipolar transcoronary and transvenous pacing.

Predictive value of outcome scores in patients suffering from cardiogenic shock complicating AMI: APACHE II, APACHE III, Elebute-Stoner, SOFA, and SAPS II.

BACKGROUND: Scoring systems in critical care patients are essential for prediction of outcome and for evaluation of therapy. In this study we determined the value of the APACHE II, APACHE III, Elebute-Stoner, SOFA, and SAPS II scoring systems in the prediction of mortality in patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI). MATERIAL AND METHODS: In this prospective, observational study, patients who were admitted to the ICU with CS complicating AMI were consecutively included. Data for the APACHE II, APACHE III, Elebute-Stoner, SOFA, and SAPS II scores were recorded on admission and during the following 96 h. Receiver operating characteristic curve analyses and the area under the curve (AUC) were used to estimate the predictive ability (mortality) of the scoring systems on admission and the maximum value. RESULTS: Mortality among the 41 patients included in this study was 44 %. On admission, the mean APACHE II (p = 0.035), APACHE III (p = 0.003), SAPS II (p = 0.001), and SOFA (p = 0.042) scores were significantly higher in nonsurvivors than in survivors. At maximum score, APACHE II (p = 0.009), APACHE III (p < 0.001), and SAPS II (p < 0.001) appeared to have higher significance. On admission, the discrimination for APACHE III was 0.786, for SAPS II 0.790, and for APACHE II 0.691. The maximum-score AUC for APACHE II was 0.726, for APACHE III 0.827, and for SAPS II 0.832. Elebute-Stoner and SOFA did not yield valuable results at maximum score or, in the case of Elebute-Stoner, on admission. CONCLUSION: These results suggest that at the time of diagnosis and at maximum value, the SAPS II, APACHE III, and APACHE II scores may be useful in predicting a high probability of survival of patients with CS complicating AMI.

Acute myocardial infarction and cardiogenic shock: prognostic impact of cytokines: INF-γ, TNF-α, MIP-1ß, G-CSF, and MCP-1ß.

BACKGROUND: The IABP SHOCK trial was designed as a morbidity-based randomized controlled trial to determine the effect of intraaortic balloon pulsation (IABP) in patients with infarct-related cardiogenic shock (CS). The primary endpoint was the change in the APACHE II score over a 4-day period. The prospective hypothesis was that adding IABP therapy to "standard care" would reduce CS-triggered multiorgan dysfunction syndrome (MODS). The primary endpoint showed no difference between conventionally managed cardiogenic shock patients and those with additional IABP support. In an inflammatory marker substudy, we analyzed the prognostic value of the cytokines interferon-γ (INF-γ), tumor necrosis factor-α (TNF-α), macrophage inflammatory protein-1ß (MIP-1ß), granulocyte-colony stimulating factor (G-CSF), and monocyte chemoattractant protein-1ß (MCP-1ß). We also investigated the influence of IABP support, age, and gender on cytokine levels. DESIGN: The inflammatory marker substudy of the prospective, randomized, controlled, open label IABP SHOCK Trial (ClinicalTrials.gov ID NCT00469248). MATERIALS AND METHODS: A prospective, randomized, single-center study in a 12-bed intensive care unit at a university hospital was performed. A total of 40 consecutive patients were enrolled. The observational period was 96 h. RESULTS: The investigated cytokines showed a significant contribution in the prediction of mortality. Initial (on admission) and maximal cytokine levels during the observational period showed a similar predictive power. Patients with elevated levels of pro- and antiinflammatory cytokines had a higher risk of dying. The maximal level measured over the observation period in the hospital was also suited to identify the survivors. Close correlations between maximal cytokine levels resulted in the choice of only one independent marker (MIP-1ß) into the multivariate model (OR 1.024, 95% CI 1.005-1.043). Initial cytokine levels were also suitable to predict the survivors; the risk of death significantly increases with increasing IFN-γ level (OR 1.119, 95% CI 1.005-1.246). Cytokine levels were not affected by the presence of IABP support. Age (< 75 or > 75 years) and gender did not have a clinically relevant effect on INF-γ, TNF-α, MIP-1ß, G-CSF, and MCP-1 in CS patients. CONCLUSION: The inflammatory response in patients with myocardial infarction complicated by CS, as reflected by the inflammatory markers INF-γ, TNF-α, MIP-1ß, G-CSF, and MCP-1ß, have been shown to be of prognostic value in estimating clinical outcome.

Resting energy expenditure in obese children aged 4 to 15 years: measured versus predicted data.

AIM: To measure the relationship of resting energy expenditure (REE) and body composition, and to compare REE data calculated from anthropometric parameters using published equations with measurements obtained by indirect calorimetry (IC) in a population of obese paediatric patients. METHODS: The study included 82 healthy obese paediatric subjects (49 boys, 33 girls; body mass index 29.6 +/- 5.0 kg/m , age 1 1.4 +/- 2.6 y, weight 72.4 +/- 20.9 kg, height 155 +/- 14 cm). REE was measured by IC, body composition was determined by dual energy X-ray absorptiometry (DXA). Bootstrap analysis was performed to validate the step-down linear regression analysis results. RESULTS: Lean body mass (LBM) and weight were identified as the most significant determinants of REE. LBM was the best single predictor (r = 0.78; p < 0.001) for REE. Regression equations are given in the text. Prediction of REE on the basis of published anthropometric formulas was strongly dependent from the equation used. Some equations tend to underestimate REE in the population studied with a considerable systematic error. CONCLUSION: In the present paper we show that (1) the published equations to predict REE in obese subjects yield scattered data and some are even biased by a systematic error, and that (2) the inclusion of DXA-derived LBM improves accuracy and precision of predicted REE in boys and girls aged from 4 to 10 y and in boys from 11 to 15 y.

Co-localization of neurophysin- and enkephalin-like immunoreactivity in cat pituitary.

Enkephalin and neurophysin immunoreactivity have been co-localized in terminals of frozen-dried cat posterior pituitary, using two methods of immunocytochemistry--the protein A-gold procedure and the PAP method. Absorption controls show reduced staining in all cases. Intermediate lobe cells are negative using the enkephalin and neurophysin antisera, but with alpha-MSH antiserum, posterior lobe terminals are negative and intermediate lobe cells are positive. The data are compatible with the hypothesis that inhibition of release of oxytocin and vasopressin by the pituitary opioid system is accomplished by an autoregulatory mechanism in which the release of enkephalin with oxytocin or vasopressin serves to inhibit release of the neurohormones.