Research progress of red distribution width in atrial fibrillation / 中国综合临床

Red blood cell distribution width is an index reflecting the size heterogeneity of circulating red blood cells, which is usually used for diagnosis and treatment of blood system diseases.In recent years, more and more evidences show that the increase of red blood cell distribution width level is closely related to the occurrence, development and prognosis of cardiovascular diseases.We focused on the relationship between red blood cell distribution width and atrial fibrillation (AF) and its possible mechanism, in order to provide some reference value for the clinical treatment of AF.

Transmural mechanics at the infarcted myocardium of a dog model of acute myocardial infarction / 中国组织工程研究

BACKGROUND:Acute myocardial infarction with acute onset is dangerous, but the aided diagnosis for hyperacute disease mainly depends on electrocardiogram. The advantages of tissue Doppler strain imaging were utilized to help early diagnosis of acute myocardial infarction. OBJECTIVE:To observe left ventricular transmural peak radial strain and strain time-to-peak of subendocardiac muscle, midmyocardium and subepicardiac muscle using tissue Doppler strain imaging in dogs before and after acute myocardial infarction, and to assess its mechanical characteristics. METHODS:A total of 16 Beagle dog models of acute myocardial ischemia were established by ligating left anterior descending coronary artery. The two-dimensional apical short-axis views of the left ventricle in five complete cardiac cycles were acquired and stored in TDI-Q workstation before and after acute myocardial ischemia. Transmural peak radial strain and strain time-to-peak of segment, subendocardiac muscle, midmyocardium and subepicardiac muscle at infarct region and baseline were observed. RESULTS AND CONCLUSION:Peak radial strains at infarct and subendocardiac muscle, midmyocardium and subepicardiac muscle were decreased compared with the baseline (P0.05;r=0.218, P>0.05). Results indicated that after acute myocardial infarction, peak strain gradient disappeared at different layers at infarct region. Acute myocardial ischemia induces peak radial strain decrease at subendocardium, medium, subepicardium and strain time-to-peak at infarct region was significantly postponed, which reflected abnormal cardiac structure and dysfunction, resulted in uncoordinated cardiac motion and asynchronous heart movement. This may be an important mechanical mechanism triggering heart failure.