Subepicardial microischemia formation induced by epicardial application of endothelin-1

[Pneumonectomy for Non-small Cell Lung Cancer: Predictors of Operative Mortality and Survival]

外科手术是目前根治非小细胞肺癌（non-small cell lung cancer, NSCLC）的最有效方式。全肺切除作为一种术式被应用于临床中。对于中央型肺癌，袖式肺叶切除术因其术后肺功能丧失少、术后并发症及死亡率低逐渐取代全肺切除术成为主流。然而为保证肿瘤学效果，当其他术式无法完全切除时，全肺切除术式仍是必要的。全肺切除术后主要发生心肺并发症，充分了解全肺切除术后相关并发症能帮助临床医师及时做出诊断，并进一步采取相关措施降低术后并发症对患者的不良影响。充分了解预后相关危险因素可帮助临床医师提前采取措施尽可能规避风险，从而改善患者预后。

Acute subepicardial infarction associated with severe septic shock--insight in myocardial perfusion

Isolated infarctions of the subepicardial myocardium without changes in subendocardium are extremely rare. We present an autoptic case with an acute subepicardial infarction of the right- and left-ventricular myocardium. A 53-year-old male was admitted to hospital with acute upper abdominal pain. Clinical examination revealed an acute infero-lateral myocardial infarction. The patient succumbed to acute heart failure a few hours later. Autopsy revealed numerous pulmonary abscesses due to suppurative lobular pneumonia with consecutive pericardial effusion. Furthermore, we diagnosed an acute myocardial infarct encompassing the entire right and left ventricles but limited to the subepicardial myocardium only. Microscopically, we observed fibrin microemboli in the subepicardial microvessels. The existence of an isolated subepicardial myocardial infarct challenges our understanding of myocardial perfusion.

Congenital pericardial defect: report of two cases and literature review

The authors report two cases of congenital pericardial defect and emphasize the role of MRI as a diagnostic tool. A review of the development of the pericardium and of the various possible explanations dealing with these abnormalities is then presented. Finally, clinical data and diagnosis and therapeutic options are discussed.

Locally different role of atrial natriuretic peptide (ANP) in the pericardial fluid

Pericardial fluid (PF) contains several vasoactive agents in higher concentrations than venous plasma (VP). However, with human atrial natriuretic peptide (ANP) controversial data have been reported in earlier studies performed on a limited number of patients (less than 20). The present study was designed to characterize the ANP levels in human PF and cardiac tissues, and to ascertain whether myocardial ischemic state is a major factor in determining ANP production of the human heart. In a total of 316 consecutive patients undergoing open heart surgery ANP levels in VP, PF, atrial and ventricular tissues were measured by radioimmunoassay and analyzed by high-performance liquid chromatography (HPLC). The data are presented as median and 25th-75th percentiles. Our results showed ANP concentration [ANP] of PF significantly exceeded that of VP and [ANP] in the atrial tissue was significantly higher than in the ventricular tissue (p < 0.001). In patients without myocardial ischemia (valvular heart disease) [ANP] in the PF was 258.3 (189.9-342.5) pg/ml, in the VP 28.4 (11.7-57.6) pg/ml and 151.7 (78.4-447.6) ng/mg in the atrial, 0.4 (0.2-1.6) ng/mg in the ventricular tissue. The corresponding values for patients with coronary artery disease were 208.1 (153.8-318.9) pg/ml in the PF, 19.8 (9.4-27.9) pg/ml in the VP, 129.6 (66.5-455.0) ng/mg in the atrial and 1.0 (0.1-1.8) ng/mg in the ventricular tissue. The ventricular tissue levels correlated to the atrial tissue levels (r = 0.317; p < 0.05). Great difference (p < 0.001) was found in the atrial tissue levels between females [414.6 (119.7-734.4) ng/mg] and males [105.4 (65.3-204.2) ng/mg]. In HPLC analysis the majority of the pericardial fluid and tissue ir-ANP coeluted with human ANP [99-126]. In conclusion, [ANP] in PF of cardiosurgical patients is higher by an order of magnitude than in VP. Intrapericardial ANP may reflect the peptide concentration in the myocardial interstitium and may represent a paracrine regulatory mechanism, which seems independent of ANP-induced putative antiischemic influences.

High pericardial fluid levels of endothelin are not caused by altered neutral endopeptidase activity in cardiac patients

We have previously detected in cardiac patients severalfold higher levels of endothelin (ET) in the pericardial fluid (PF) than in the plasma (PL). We postulated that this is due to different activities of neutral endopeptidase (NEP) in the two compartments. With approval of the ethical committee and informed consent by 32 patients (18 men, 14 women, aged 62 +/- 2 years; NYHA II-IV), PF was taken during cardiac surgery. PL samples were obtained on the day of surgery before premedication. ET was measured by radioimmunoassay after extraction (SepPakC18). NEP activity was measured by a microplate-based kinetic enzyme assay over 120 min. PF ET (78 +/- 11 pg/ml) was significantly (p < 0.05) higher than PL ET (3.38 +/- 0.48 pg/ml). The PF/PL ratio was 38 +/- 14, range 7-200. PF ET was inversely related to the NYHA state of the patients, whereas a similar relation was not found with PL ET. PL and PF ET levels did not correlate. In HPLC, the total immunoreactive ET activity co-eluted with the human ET standard. PF NEP activity (2.26 +/- 0.12 U/l) was lower (p < 0.05) than PL NEP (3.62 +/- 0.22 U/I). PL NEP was not different from that of healthy controls (3.28 +/- 0.22 U/L; n = 50). No correlation was found between NEP in either compartment and the NYHA state of the patients. ET concentration and NEP activity did not correlate in PF or PL. We conclude that ET is extremely high in the PF of cardiac patients and that this is not caused by altered NEP activity.

Presence of immunoreactive endothelin-1 and atrial natriuretic peptide in human pericardial fluid

This study was undertaken to characterize endothelin-1 (ET-1) and atrial natriuretic peptide (ANP) concentrations in human pericardial fluid, blood plasma, right atrial appendage and papillary muscle by use of specific radioimmunoassays. In patients undergoing cardiac surgery (n=16) pericardial fluid mean immunoreactive (ir-) ET-1 and ir-ANP levels were 36-fold and 4-fold higher than corresponding plasma levels, respectively. In high performance liquid chromatography (HPLC) pericardial fluid ir-ET-1 was indistinguishable from human ET-1[1-21] and the majority of pericardial fluid ir-ANP coeluted with human ANP[99-126]. Atrial tissue ir-ET-1 and ir-ANP concentrations were 17-fold and 870-fold higher than in ventricular tissue. Our present study demonstrated for the first time the presence of ir-ET-1 in the pericardial fluid in humans. Human pericardial fluid contained far the highest concentrations of ET-1 among all biological fluids tested thus far. The functions of pericardial fluid ET-1 and ANP on cardiac performance and coronary vascular tone require further investigations.

Role of endogenous endothelin in myocardial and coronary endothelial injury after ischaemia and reperfusion in rats: studies with bosentan, a mixed ETA-ETB antagonist

1. Previous studies suggested that endothelin-1 (ET-1) may play a role in myocardial ischaemia and reperfusion. This study was designed to test the effect of a new nonpeptide antagonist of endothelin ETA and ETB receptors, bosentan, on myocardial infarct size, ventricular arrhythmias, and coronary endothelial dysfunction after ischaemia and reperfusion. 2. Anaesthetized male Wistar rats were subjected to 20 min ischaemia (left coronary artery occlusion) followed by 1 h (for the evaluation of coronary endothelial dysfunction) or 2 h (for the evaluation of infarct size) reperfusion, or 5 min ischaemia followed by 15 min reperfusion (for the evaluation of reperfusion arrhythmias). Vascular studies were performed on 1.5-2 mm coronary segments (internal diameter 250-300 microns) removed distal to the site of occlusion and mounted in wire myographs for isometric tension recording. Area at risk and infarct size were determined by Indian ink injection and triphenyl tetrazolium staining, using computerized analysis of enlarged sections after colour video acquisition. 3. Bosentan, administered at a dose which virtually abolished the pressor response to big ET-1 (3 mg kg-1, i.v. before ischaemia) did not affect heart rate, arterial pressure or the rate pressure product before ischaemia, during ischaemia and during reperfusion. Bosentan did not affect the incidence of reperfusion-induced ventricular fibrillation (controls: 86%, n = 14; bosentan: 93%, n = 15), and did not modify infarct size (% of area at risk: controls: 63 +/- 4, n = 10; bosentan: 60 +/- 6, n = 8). Ischaemia followed by reperfusion markedly reduced the endothelium-dependent relaxations to acetylcholine(maximal response: sham: 59 +/- 4%, n = 9; ischaemia-reperfusion: 26+/- 6%, n = 8; P<0.01), characteristic of reperfusion-induced endothelial dysfunction, and this dysfunction was not prevented by bosentan (maximal response to acetylcholine: 25 +/-5%, n = 9; P<0.01 vs sham; P = NS vs ischaemia/reperfusion).4. These experiments suggest that endogenous endothelin does not contribute to myocyte or coronary endothelial injury in this rat model of ischaemia and reperfusion.