This study indicates that fibrin glue increases cell transplant survival, decreases infarct size, and increases blood flow to ischemic myocardium. Therefore, fibrin glue may have potential as a biomaterial scaffold to improve cellular cardiomyoplasty treat and MIs.

Current efforts in cardiac tissue engineering center around the use of scaffolds that deliver cells to the epicardial surface. In this study, we examined the effects of fibrin glue as an injectable scaffold and wall support in ischemic myocardium. The left coronary artery of rats was occluded for 17 min, followed by reperfusion. Echocardiography was performed 8 days after infarction. One to 2 days later, either 0.5% bovine serum albumin (BSA) in phosphate-buffered saline, fibrin glue alone, skeletal myoblasts alone, or skeletal myoblasts in fibrin glue were injected into the ischemic left ventricle. Echocardiography was again performed 5 weeks after injection. The animals were then sacrificed and the hearts were fresh frozen and sectioned for histology and immunohistochemistry. Both the fractional shortening (FS) and infarct wall thickness of the BSA group decreased significantly after 5 weeks (p = 0.0005 and 0.02, respectively). In contrast, both measurements for the fibrin glue group, cells group, and cells in fibrin glue group did not change significantly (FS: p = 0.18, 0.89, and 0.19, respectively; wall thickness: p = 0.40, 0.44, 0.43, respectively). Fibrin glue is capable of preserving infarct wall thickness and cardiac function after a myocardial infarction in rats and may be useful as a biomaterial scaffold for myocardial cell transplantation.

LAA closure with the LARIAT device can be performed effectively with acceptably low access complications and periprocedural adverse events in this observational study.

Skeletal muscle consists of parallel bundles of myotubes formed by the fusion of myoblasts. We fabricated nanofibrous and micropatterned polymers as cell culture substrates to guide the morphogenesis of muscular tissue. The nanoscale and microscale topographic features regulate cell and cytoskeleton alignment, myotube assembly, myotube striation, and myoblast proliferation. This bottom-up approach from nanoscale to tissue level demonstrates the potential of nanofibrous polymers for engineering the assembly of cell and tissue structure.

For nearly a decade, researchers have investigated the possibility of cell transplantation for cardiac repair. More recently, the emerging fields of tissue engineering and biomaterials have begun to provide potential treatments. Tissue engineering approaches are designed to repair lost or damaged tissue through the use of growth factors, cellular transplantation, and biomaterial scaffolds. There are currently 3 biomaterial approaches for the treatment of myocardial infarction (MI). The first involves polymeric left ventricular restraints in the prevention of heart failure. The second utilizes in vitro engineered cardiac tissue, which is subsequently implanted in vivo. The final approach entails injecting cells and/or a scaffold into the myocardium to create in situ engineered cardiac tissue. This review gives an overview of the current progress in the growing field of biomaterials for the treatment of MI.

Myocardial infarct size measurement in the mouse chronic infarction model: comparison of area-and length-based approaches. J Appl Physiol 102: 2104 -2111, 2007. First published March 8, 2007; doi:10.1152/japplphysiol.00033.2007.-Efficacy of potential treatments for myocardial infarction (MI) is commonly assessed by histological measurement of infarct size in rodent models. In experiments involving an acute MI setting, measurement of the infarcted area in tissue sections of the left ventricle is a standard approach to determine infarct size. This approach has also been used in the chronic infarct setting to measure infarct area several weeks post-MI. We tested the hypothesis that, because wall thinning is known to occur in the chronic setting, the area measurement approach would be less appropriate. We compared infarct measurements in tissue sections based on 1) infarct area, 2) epicardial and endocardial infarct arc lengths, and 3) midline infarct arc length. Infarct sizes from all three measurement approaches correlated significantly with left ventricular ejection fraction and wall motion abnormality. However, the infarct size values derived from the area measurement approach were significantly smaller than those from the other two measurement approaches, and the range of values obtained was compressed 0.4-fold. The midline method allowed detection of the expected size differences between infarcts of variable severity resulting from proximal vs. distal ligation of the coronary artery. Segmental infarct size was correlated with segmental wall motion abnormality. We conclude that both area-and length-based measurements can be used to determine relative infarct size over a wide range of severity, although the area-based measurements are substantially more compressed due to wall thinning, and that the estimation of infarct midlines is a simple, reliable approach to infarct size assessment. cardiac remodeling; area-based measurement; length-based measurement; histology RODENT MODELS OF MYOCARDIAL infarction (MI) have been frequently used to elucidate the pathophysiological and molecular mechanisms of cardiac remodeling after the onset of MI (5,7,18,19,23,24). In recent years, the delivery of potentially therapeutic genes and the implantation of stem cells have attracted much interest and have been evaluated with the use of rat or mouse MI models (2,4,9,12,14,21,22). In many published studies exploring these potential therapies, success has commonly been evaluated by determination of infarct size, as well as by functional and other histological parameters. In experiments involving an acute MI setting, infarct size is typically based on histological measurement of the area of the infarcted region in tissue sections of the left ventricle (LV) (13,16,20,26). In contrast, histological measurement of the arc length of the infarct scar has been commonly used in a chronic MI setting (8,14,18,19). Although it is well known that there is progressive thinning of the infarcted wall with reduction in the volume of the infarcted...

Radiofrequency catheter ablation is an effective treatment for idiopathic ventricular tachycardia. The site of origin of tachycardia is best identified using pace mapping. Significant complications can occur and should be considered in the risk/benefit analysis for each patient.

1) Analyses of surface P wave configuration proved to be reasonably good in differentiating right atrial from left atrial tachycardia foci. 2) Leads II, III and aVF were helpful in providing clues for differentiating superior from inferior foci.