Imaging and Modeling of Myocardial Metabolism

Current imaging methods have focused on evaluation of myocardial anatomy and function. However, since myocardial metabolism and function are interrelated, metabolic myocardial imaging techniques, such as positron emission tomography, single photon emission tomography, and magnetic resonance spectroscopy present novel opportunities for probing myocardial pathology and developing new therapeutic approaches. Potential clinical applications of metabolic imaging include hypertensive and ischemic heart disease, heart failure, cardiac transplantation, as well as cardiomyopathies. Furthermore, response to therapeutic intervention can be monitored using metabolic imaging. Analysis of metabolic data in the past has been limited, focusing primarily on isolated metabolites. Models of myocardial metabolism, however, such as the oxygen transport and cellular energetics model and constraint-based metabolic network modeling, offer opportunities for evaluation interactions between greater numbers of metabolites in the heart. In this review, the roles of metabolic myocardial imaging and analysis of metabolic data using modeling methods for expanding our understanding of cardiac pathology are discussed

Report of a case of Streptococcus agalactiae mycotic aneurysm and review of the literature.

A unique case of mycotic aneurysm of the abdominal aorta caused by Streptococcus agalactiae in an afebrile patient presenting with abdominal pain is described. Although this bacterium is associated with a variety of infections in human beings, aortitis is uncommon. Chronic alcoholism and diabetes mellitus are the 2 major predisposing conditions for group B Streptococci infection and both were present in this case. The abdominal pain and elevated inflammatory markers in the absence of fever were elusive in presentation; however, the diagnosis of mycotic aneurysm was established by abdominal computed tomography scan. The patient was treated successfully by resection of the diseased aorta and aortic allograft replacement. Culture of the excised tissue grew Streptococcus agalactiae sensitive to penicillin G and (other commonly tested antibiotics) fluoroquinolones. A prolonged course of moxifloxacin (for 6 months) was administered due to the persistence of elevated inflammatory markers and was remarkably well tolerated. Sixteen months after stopping the antibiotics, the patient is doing well, and the control imaging studies are satisfactory