Antonio Maria Calafiore

Effect of ischaemia-reperfusion on glutathione peroxidase, glutathione reductase and glutathione transferase activities in human heart protected by hypothermic cardioplegia.

The activities of glutathione peroxidase (GSH-px), glutathione reductase (GSSG-rx) and glutathione transferase (GST) were measured in myocardial specimens obtained from right atria of patients subjected to different period of ischaemic arrest (aortic clamping ranging from 10 min to 90 min) followed by 60 min. of reperfusion, during open heart surgery 41-90 min. period of aortic clamping induced a significant increase of GSH-px activity with both H2O2 (p less than 0.05) and cumene hydroperoxide (p less than 0.025) as substrates when compared with baseline levels. Aortic clamping and reperfusion, however did not significantly change the myocardial activities of glutathione transferase and glutathione reductase. It is suggested that the increase of GSH-px in ischaemic-reperfused human hearts may render the myocardium less susceptible to oxidative attack particularly during the reoxygenation period when the level of active oxygen species is greatly elevated.

Glutathione-related enzyme activities and lipoperoxide levels in human internal mammary artery and ascending aorta. Relations with serum lipids.

The relation among glutathione-related enzyme activities, thiobarbituric acid-reactive substances of the human aorta and internal mammary artery, and serum lipids was studied in 40 male patients undergoing coronary revascularization. Glutathione peroxidase and glutathione reductase activities were significantly higher in the internal mammary artery, whereas glutathione transferase activity was elevated in the aortic wall. Moreover, non-selenium-dependent glutathione peroxidase activity was detectable only in the aorta. The levels of thiobarbituric acid-reactive substances were significantly higher in the aorta. A positive correlation was found among the activity of glutathione peroxidase, glutathione reductase, and thiobarbituric acid-reactive substances in the internal mammary artery and total cholesterol, low density lipoprotein cholesterol, and triglycerides. In the aortic wall, a positive correlation among the activity of glutathione peroxidase, glutathione transferase, thiobarbituric acid-reactive substances, and the previously mentioned serum lipids was evident. In contrast, high density lipoprotein cholesterol was inversely related to enzymatic activities and thiobarbituric acid-reactive substances in both the internal mammary artery and aorta. In conclusion, significant differences in the levels of glutathione-related enzyme activities and thiobarbituric acid-reactive substances in the internal mammary artery and aorta were found, suggesting a different ability of the two tissues to counteract oxidative stress: the glutathione-related antioxidant properties and the level of lipid peroxidation in the arterial tissue seem to be specifically influenced by serum lipids.

Minimally Invasive Coronary Artery Bypass Grafting on the Beating Heart: The European Experience

The prospect of grafting the internal mammary artery (IMA) to the left anterior descending (LAD) artery via a thoracotomy without the aid of cardiopulmonary bypass (CPB) was first explored by Kolessov in 1967 (1), and further applied by Favaloro (2), Garrett (3), Trapp (4), and others. The early wave of enthusiasm for this technique soon wavered with the widespread availability of CPB and cardioplegia, which allowed for a motionless and bloodless operative field. The unequivocal and widespread success of conventional coronary artery bypass grafting (CABG) limited the use of unsupported bypass grafting. Two developments in the early 1990s revived the technique of myocardial revascularization without CPB: (1) the emergence of minimally invasive technology applicable to the chest, and (2) the promising results of “pumpless” bypass grafting reported by a number of authors (5–7). In our opinion, the definition of minimally invasive cardiac surgery encompasses all approaches that avoid cardiopulmonary bypass, regardless of mode of surgical access

Right Ventricle and Functional Tricuspid Regurgitation: An Unpredictable Interaction

The tricuspid valve (TV) lies in between the right atrium and the right ventricle (RV), consisting of annulus, leaflets, chords and papillary muscles. The RV appears triangular-shaped in a lateral viewed and crescent-shaped in a cross-section one. In normal conditions, the septum is concave toward the left ventricle (LV) in both systole and diastole and the RV volume is larger than the LV volume, Although its mass is one-third of the LV. The strict relationship between the tricuspid valve apparatus and the RV underlies the physiological mechanism of TV functioning, so, the RV plays an important role in case of functional tricuspid regurgitation (FTR). Nevertheless the systematic assessment of RV is still not performed mainly due to lack of standardization. Hence, new echocardiographic guidelines have been recently proposed to standardized the RV assessment using trans-thoracic 2D echocardiography. Three-D-echocardiography and magnetic resonance imaging (MRI) are more useful to measure volumes and ejection fraction; in particular, MRI is able to provide a tissue evaluation. Today, surgical strategies are directed mainly to the annulus with fluctuating results, because FTR in not due only to the annulus but also to the RV that is difficult to assess, being its evolution unpredictable and complicated by the interaction with LV.

Mitral Prosthesis Insertion for Functional Mitral Regurgitation: Indications and Results

Mitral regurgitation (MR) is the most frequent valvulopathy in the general population (up to 9.3% in the elderly). The main pathogenesis is “functional” and this is a negative prognostic factor for both survival or occurrence of heart failure. Hence, the presence of moderate or more functional MR has to be always treated. There is general agreement that overreductive mitral annuloplasty. Nevertheless, the evolution of MR after surgical correction is not always favorable. In patients with high grade of papillary muscles displacement, mitral prosthesis insertion should be preferable to mitral repair, taking in account the preservation of the mitral apparatus. In conclusion, the surgical treatment of functional MR has to be tailored in order to offer the best option for every single patient

Activity of Glutathione-Related Enzymes in Ischemia and Reperfusion Injury

Myocardial ischemic injury is caused by severe impairment of the coronary blood supply usually produced by thrombosis or other acute alterations of coronary atherosclerotic plaques. Intense investigation has led to considerable insight into the pathobiology of myocardial ischemic injury.1,2

Multislice Spiral Computed Tomography–Assisted Vein Graft Stenting

A 73-year-old woman presented with angina pectoris 2 years after bypass surgery with left internal mammary artery to left anterior descending coronary artery and a saphenous vein graft (SVG) to the obtuse marginal branch (OM) and the posterior descending artery (PDA). On admission, the chest radiograph showed an enlarged mediastinum; no pleural effusion was present. An ECG-gated multislice spiral computed tomography (MSCT) was performed. Axial (Figure 1A) and 3D volume–rendered (Figure 1B) images showed a subacute …