…aorta. Afterload affects myocardial muscle fibers during systole and diastole. Afterload is a function of the following three variables: Aortic resistance (pressure). Left ventricular volume…

Echocardiography Structure and contractile function of myocardial fibers The left ventricular wall can be subdivided into several layers. These layers are similar to those seen…

…The orientation of myocardial muscle fibers results in longitudinal, radial and circumferential shortening (contraction). Traditional methods for investigating left ventricular function — e.g ejection fraction…

…of them are easy to use and require very little calculation. Sensitivity and specificity vary markedly, as discussed in detail in the articles on left…

…severe left ventricular (LV) dysfunction, accounting for approximately 80% of cases. Other causes include acute mechanical complications—particularly ventricular septal defect (VSD) and papillary muscle…

…and the development of myocardial fibrosis. Contractile dysfunction further aggravates the regurgitation (the regurgitation volume increases). Mechanically, wall stress (the load on individual muscle fibers)…

…ventricles. When the contractile myocardium receives the action potential, it is activated and contracts. Figure 1 illustrates the relevant components of the conduction system, the…

…as follows: Sympathetic activity causes constriction of the veins, which increases the venous return to the heart. Contracting muscles function as a pump that propels…

…degradation. Histologically, a vulnerable plaque is defined by a fibrous cap thickness of less than 65 μm, heavy macrophage infiltration, sparse smooth muscle c

…injury. Mechanisms of troponin release Troponin I and troponin T are components of the myocardial contractile apparatus and are expressed predominantly in cardiac muscle. Troponin…