No abstract available.
Humans ; Infarction* ; Ventricular Remodeling*

Nitric Oxide Synthase ; Ventricular Remodeling

Autophagy ; Humans ; Myocytes, Cardiac ; Ventricular Remodeling

Cellular Senescence ; Heart ; Humans ; Ventricular Remodeling

There is considerable clinical and experimental evidence of the benefit of late reperfusion of infarct-related arteries, referred to as the open artery hypothesis, in patients with acute myocardial infarction who presented too late to salvage at-risk ischemic myocardium. In addition to myocardial salvage, reperfusion of the infarct-related artery prevents infarct expansion, reduces development of ventricular remodeling, and decreases ventricular arrhythmia. The Occluded Artery Trial recently answered a major question related to the open artery hypothesis in a high-risk, asymptomatic patient with an occluded infarct artery. In this review, clinical and experimental evidence of the benefit of the open artery hypothesis will be discussed.
Arrhythmias, Cardiac ; Arteries* ; Humans ; Myocardial Infarction ; Myocardium ; Reperfusion ; Ventricular Remodeling

Myocardial infarction (MI) is one of the leading causes of death in the world. With the improvement of clinical therapy, the mortality of acute MI has been significantly reduced. However, as for the long-term impact of MI on cardiac remodeling and cardiac function, there is no effective prevention and treatment measures. Erythropoietin (EPO), a glycoprotein cytokine essential to hematopoiesis, has anti-apoptotic and pro-angiogenetic effects. Studies have shown that EPO plays a protective role in cardiomyocytes in cardiovascular diseases, such as cardiac ischemia injury and heart failure. EPO has been demonstrated to protect ischemic myocardium and improve MI repair by promoting the activation of cardiac progenitor cells (CPCs). This study aimed to investigate whether EPO can promote MI repair by enhancing the activity of stem cell antigen 1 positive stem cells (Sca-1⁺ SCs). Darbepoetin alpha (a long-acting EPO analog, EPO_anlg) was injected into the border zone of MI in adult mice. Infarct size, cardiac remodeling and performance, cardiomyocyte apoptosis and microvessel density were measured. Lin^- Sca-1⁺ SCs were isolated from neonatal and adult mouse hearts by magnetic sorting technology, and were used to identify the colony forming ability and the effect of EPO, respectively. The results showed that, compared to MI alone, EPO_anlg reduced the infarct percentage, cardiomyocyte apoptosis ratio and left ventricular (LV) chamber dilatation, improved cardiac performance, and increased the numbers of coronary microvessels in vivo. In vitro, EPO increased the proliferation, migration and clone formation of Lin^- Sca-1⁺ SCs likely via the EPO receptor and downstream STAT-5/p38 MAPK signaling pathways. These results suggest that EPO participates in the repair process of MI by activating Sca-1⁺ SCs.
Animals ; Mice ; Ventricular Remodeling ; Erythropoietin ; Myocardial Infarction ; Heart ; Stem Cells

Connective Tissue Growth Factor ; Humans ; Myocardial Infarction ; physiopathology ; Ventricular Remodeling

Animals ; Medicine, Chinese Traditional ; methods ; Phytotherapy ; Ventricular Remodeling

Humans ; Myocardial Infarction ; physiopathology ; Ventricular Function, Left ; immunology ; Ventricular Remodeling ; immunology

OBJECTIVETo compare the results of echocardiographic evaluation of pressure overload-induced cardiac remodeling in mice using different ultrasound machines.

METHODSEighteen C57 BL/6 mice were randomly divided into the sham-operated and the transverse aortic constriction (TAC) groups (n=9). Eight weeks after the operation, the cardiac function of TAC group was evaluated using Siemens ultrasonic instrument with 15L8 probe and the differences between the awake and anesthetized states were compared. The heart rate, left ventricular (LV) dimensions, systolic and diastolic functions were measured in both sham-operated and TAC groups using the Siemens ultrasonic instrument and a high-resolution ultrasonic imaging system for small animals (Vevo 770).

RESULTSCompared with the mice in wakefulness, the anesthetized mice showed significantly decreased heart rate and LV fractional shortening (P<0.001) and markedly increased LV end diastolic diameter and LV end systolic diameter (P<0.05). Both machines sensitively detected the cardiac remodeling of TAC mice in comparison with the sham-operated group. Compared with Siemens machine, Vevo 770 provided a higher resolution of 2D and M mode echocardiography with clearer Doppler frequency image of the mitral valve flow for evaluation of the LV diastolic function.

CONCLUSIONBoth machines are suitable for evaluating cardiac remodeling induced by pressure overload independent of anesthesia, though anesthesia depresses cardiac function. Vevo 770 is optimal to evaluate LV diastolic function in mice.

Animals ; Echocardiography ; instrumentation ; Hypertrophy, Left Ventricular ; diagnostic imaging ; Male ; Mice ; Mice, Inbred C57BL ; Ventricular Remodeling ; physiology