…to the sequence of activation of the ventricular myocardium. The ventricles should be depolarized (activated) by impulses spreading through the left and right bundle branch…

…Hypertrophy manifests on the ECG as increased amplitudes of the QRS complexes. The explanation is straightforward: myocardial muscle mass is increased and therefore it generates…

…80% of cases. Other causes include acute mechanical complications—particularly ventricular septal defect (VSD) and papillary muscle rupture with acute severe mitral regurgitation—predominant right…

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…

…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…

…g ejection fraction (EF), fractional sorting (FS), etc — do not elucidate regional variations in contractile function, or the effectiveness of longitudinal, radial, and circumferential contraction…

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

…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)…

…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…