Accuracy of echocardiographic area-length method in chronic myocardial infarction: comparison with cardiac CT in pigs

Background: We evaluated echocardiographic area-length methods to measure left ventricle (LV) volumes and ejection fraction (EF) in parasternal short axis views in comparison with cardiac computed tomography (CT) in pigs with chronic myocardial infarction (MI).Methods: Male farm pigs with surgical occlusion of the left anterior descending coronary artery (n = 9) or sham operation (n = 5) had transthoracic echocardiography and cardiac-CT 3 months after surgery. We measured length of the LV in parasternal long axis view, and both systolic and diastolic LV areas in parasternal short axis views at the level of mitral valve, papillary muscles and apex. Volumes and EF of the LV were calculated using Simpson's method of discs (tri-plane area) or Cylinder-hemiellipsoid method (single plane area).Results: The pigs with coronary occlusion had anterior MI scars and reduced EF (average EF 42 +/- 10%) by CT. Measurements of LV volumes and EF were reproducible by echocardiography. Compared with CT, end-diastolic volume (EDV) measured by echocardiography showed good correlation and agreement using either Simpson's method (r = 0.90; mean difference -2, 95% CI -47 to 43 mL) or Cylinder-hemiellipsoid method (r = 0.94; mean difference 3, 95% CI -44 to 49 mL). Furthermore, End-systolic volume (ESV) measured by echocardiography showed also good correlation and agreement using either Simpson's method (r = 0.94; mean difference 12 ml, 95% CI: -16 to 40) or Cylinder-hemiellipsoid method (r = 0.97; mean difference: 13 ml, 95% CI: -8 to 33). EF was underestimated using either Simpson's method (r = 0.78; mean difference -6, 95% CI -11 to 1%) or Cylinder-hemiellipsoid method (r = 0.74; mean difference -4, 95% CI-10 to 2%).Conclusion: Our results indicate that measurement of LV volumes may be accurate, but EF is underestimated using either three or single parasternal short axis planes by echocardiography in a large animal model of chronic MI

Systemic Dosing of Thymosin Beta 4 before and after Ischemia Does Not Attenuate Global Myocardial Ischemia-Reperfusion Injury in Pigs

The use of cardiopulmonary bypass (CPB) and aortic cross-clamping causes myocardial ischemia-reperfusion injury (I-RI) and can lead to reduced postoperative cardiac function. We investigated whether this injury could be attenuated by thymosin beta 4 (TB4), a peptide which has showed cardioprotective effects. Pigs received either TB4 or vehicle and underwent CPB and aortic cross-clamping for 60 min with cold intermittent blood-cardioplegia and were then followed for 30 h. Myocardial function and blood flow was studied by cardiac magnetic resonance and PET imaging. Tissue and plasma samples were analyzed to determine the amount of cardiomyocyte necrosis and apoptosis as well as pharmacokinetics of the peptide. In vitro studies were performed to assess its influence on blood coagulation and vasomotor tone. Serum levels of the peptide were increased after administration compared to control samples. TB4 did not decrease the amount of cell death. Cardiac function and global myocardial blood flow was similar between the study groups. At high doses a vasoconstrictor effect on mesentery arteries and a vasodilator effect on coronary arteries was observed and blood clot firmness was reduced when tested in the presence of an antiplatelet agent. Despite promising results in previous trials the cardioprotective effect of TB4 was not demonstrated in this model for global myocardial I-RI

Azole interactions with multidrug therapy in pediatric oncology

Patients with cancer receive multidrug therapy. Antineoplastic agents and supportive care drugs are often administered together, leading to potential drug-drug interactions. These interactions may have significant clinical implications in terms of toxicity or a decrease in the efficacy of the treatment administered. Here, we focus on the role of azoles and their main pharmacokinetic interactions with the principal classes of drugs used in pediatric oncology. The co-administration of azoles and antineoplastic agents, corticosteroids, immunosuppressants, antacids, antiemetics, antiepileptic drugs and analgesics was investigated, and a practical guide on the management of these drugs when administered together is provided