Anatomical and functional evaluation of myocardial bridging on the left anterior descending artery by cardiovascular magnetic resonance imaging.

A myocardial muscle bridge spans a segment of a major epicardial coronary artery that is located in the myocardium. This anatomic configuration can be responsible for angina pectoris, arrhythmias or even death. The current reference standard for diagnosis is conventional x-ray coronary angiography showing systolic compression of an epicardial vessel and the typical angiographic "milking effect." We report the case of a patient with myocardial bridging on the left anterior descending artery, in whom a combination of noninvasive high resolution display of the coronary artery lumen, visualization of the myocardium and functional assessment of blood flow during dobutamine stimulation by cardiovascular magnetic resonance imaging was performed.     

Prospective determination of plasma imipenem concentrations in critically ill children

Plasma imipenem concentrations were measured in 19 critically ill children (median age, 0.8 year; range, 0.02 to 12.9 years). Wide interindividual variations (2 to 4x at peak and >10x at trough concentrations) resulted in unpredictable plasma levels in several children. To avoid subtherapeutic drug levels, we recommend treatment with at least 100 mg/kg of body weight/day of imipenem-cilastatin for critically ill children requiring such therapy.     

Shared networks for auditory and motor processing in professional pianists: evidence from fMRI conjunction

To investigate cortical auditory and motor coupling in professional musicians, we compared the functional magnetic resonance imaging (fMRI) activity of seven pianists to seven non-musicians utilizing a passive task paradigm established in a previous learning study. The tasks involved either passively listening to short piano melodies or pressing keys on a mute MRI-compliant piano keyboard. Both groups were matched with respect to age and gender, and did not exhibit any overt performance differences in the keypressing task. The professional pianists showed increased activity compared to the non-musicians in a distributed cortical network during both the acoustic and the mute motion-related task. A conjunction analysis revealed a distinct musicianship-specific network being co-activated during either task type, indicating areas involved in auditory-sensorimotor integration. This network is comprised of dorsolateral and inferior frontal cortex (including Broca's area), the superior temporal gyrus (Wernicke's area), the supramarginal gyrus, and supplementary motor and premotor areas.     

Selective pressure-regulated retroinfusion of fibroblast growth factor-2 into the coronary vein enhances regional myocardial blood flow and function in pigs with chronic myocardial ischemia

OBJECTIVES: We sought to improve regional myocardial delivery and subsequent collateral perfusion induced by basic fibroblast growth factor-2 (FGF-2) using selective pressure-regulated retroinfusion of coronary veins for delivery. This hypothesis was tested in a newly developed pig model with percutaneous induction of chronic ischemia. BACKGROUND: Selective pressure-regulated retroinfusion of coronary veins is a catheter-based procedure that has been shown to provide effective regional delivery of drugs and gene vectors into ischemic myocardium. METHODS: A high-grade stenosis with subsequent progression to total occlusion within 28 days was induced by implanting a reduction stent graft into the left anterior descending artery (LAD). After seven days, a 30-min retroinfusion (anterior cardiac vein) was performed with (n = 7) or without (n = 7) 150 microg FGF-2 and compared with a 30-min antegrade infusion of 150 microg FGF-2 into the LAD (n = 7). Sonomicrometry to assess regional myocardial function at rest and during pacing, and microspheres to assess regional myocardial blood flow, were performed 28 days after implantation of the reduction stent. RESULTS: Retroinfusion of FGF-2 compared favorably with controls and with antegrade infusion of FGF-2 with regard to regional myocardial function at rest (18.5 +/- 4.1% vs. 5.7 +/- 2.9% vs. 7.9 +/- 1.8%, respectively, p < 0.05) and during pacing. Regional myocardial blood flow was also higher in the LAD territory after retroinfusion of FGF-2 (1.07 +/- 0.14 vs. 0.66 +/- 0.07 vs. 0.72 +/- 0.17 ml x min(-1) x g(-1), p < 0.05). CONCLUSIONS: Selective pressure-regulated retroinfusion increased tissue binding of FGF-2 and enhanced functionally relevant collateral perfusion compared with antegrade intracoronary delivery in pigs with chronic myocardial ischemia.     

MicroRNA signatures in total peripheral blood as novel biomarkers for acute myocardial infarction

MicroRNAs (miRNAs) are important regulators of adaptive and maladaptive responses in cardiovascular diseases and hence are considered to be potential therapeutical targets. However, their role as novel biomarkers for the diagnosis of cardiovascular diseases still needs to be systematically evaluated. We assessed here for the first time whole-genome miRNA expression in peripheral total blood samples of patients with acute myocardial infarction (AMI). We identified 121 miRNAs, which are significantly dysregulated in AMI patients in comparison to healthy controls. Among these, miR-1291 and miR-663b show the highest sensitivity and specificity for the discrimination of cases from controls. Using a novel self-learning pattern recognition algorithm, we identified a unique signature of 20 miRNAs that predicts AMI with even higher power (specificity 96%, sensitivity 90%, and accuracy 93%). In addition, we show that miR-30c and miR-145 levels correlate with infarct sizes estimated by Troponin T release. The here presented study shows that single miRNAs and especially miRNA signatures derived from peripheral blood, could be valuable novel biomarkers for cardiovascular diseases.     

Is there an advantage in using homografts in patients with acute infective endocarditis of the aortic valve?

BACKGROUND AND AIM OF THE STUDY: Acute infective endocarditis is a surgical challenge, particularly when paravalvular abscesses and annular destruction are present. The choice of a homograft or mechanical valve prosthesis is an important issue in these patients. The study aim was to compare the outcome with homografts and mechanical valves in patients with acute infective endocarditis. METHODS: A total of 77 patients (mean age 49+/-9 years) operated on for acute endocarditis of the aortic valve was included in the study and analyzed retrospectively. The causative bacterium was isolated from blood cultures in 71 cases. Preoperatively, 21 patients required artificial ventilation and 24 had inotropic support due to hemodynamic instability. Aortic homografts were implanted in 43 patients, and mechanical valve prostheses in 34. The two patient groups were similar in terms of gender, age and preoperative inotropic support. In total, 31 patients (44%) had paravalvular abscesses, and a homograft was used significantly more often (77%, p <0.05) in these cases. Follow up examinations (clinical examination, ECG and transthoracic echocardiography) were performed six months postoperatively and continued on an annual basis. Endocarditis relapse was defined as persisting infection, whereas re-endocarditis indicated a new infection after an interval of at least six months. RESULTS: Perioperative mortality was 11.5% (5/43) in homograft patients. In the 38 survivors, follow up was complete and averaged 5.0+/-1.2 years. One patient had an endocarditis relapse three months after surgery. Re-endocarditis occurred in three patients after two or three years. One other patient had pseudoaneurysm formation without a need for intervention, and one had repeat aortic valve replacement due to dysfunction of the graft after four years. The other 33 patients had an uneventful follow up. Echocardiography revealed aortic insufficiency grade 1 in 12 cases (36%), with no progression during follow up. Perioperative mortality in mechanicat valve patients was 20.5% (n = 7) (p <0.05 versus homograft), and in those with paravalvular abscess, perioperative mortality was even higher than in homograft patients (4/7, 57.1% versus 3/24, 12.5%; p <0.05). When considering only patients without paravalvular abscess, there was no significant difference between groups (10.5% versus 12.5%). Three relapses occurred in mechanical valve patients (10.3%), but no endocarditis recurred during follow up. One late death (3.7%) occurred due to bleeding complicating long-term anticoagulation. CONCLUSION: The study results do not permit a general recommendation to be made for homograft use in patients with acute endocarditis. In cases with paravalvular abscesses, however, there was a trend towards improved outcome in the homograft group.