…driven inflammatory disease of the arterial intima that serves as the fundamental pathophysiological substrate for acute coronary syndromes (ACS), including ST Elevation Myocardial Infarction (STEMI) …

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

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…

…sufficient contractile force to overcome the pressure in the aorta. The greater the pressure in the aorta, the greater the load on individual muscle fibers…

…the pressure in the aorta is increased) and aortic stenosis (in which the narrowing of the opened aortic valve orifice makes it difficult for blood…

…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…

…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…

…or subacute –lead to regional abnormalities in contractile function. The abnormalities affect the myocardial area supplied by the arteries distal to the occlusion or stenosis…

…low concentration of gap junctions in AV nodal cells), which allows for ventricular filling to complete prior to ventricular contraction. In contrast, contractile cells–and…

…differences in contractile function. Otherwise, the point of measurement may not be representative. Ventricular activation must be normal. For example, in the setting of left…

…from one contractile cell to another, starting in the endocardium and heading towards the epicardium. As evident from Figure 7 , the vector of the ventricular…

…excitability, and contractile function are all compromised by ATP depletion. Myocardial necrosis (infarction) commences within 20 minutes of circulatory collapse. The electrical phase: Defibrillate It…

…systolic function (contractile function) Several echocardiographic measurements are available to assess left ventricular systolic function. These methods elucidate slightly different aspects of systolic function and…

…conduction and contractile cells—must undergo rapid repolarization to ensure they are excitable when the next action potential occurs. If any component of the ventricular…

…contractile myocardium. When the contractile myocardium receives the action potential, it is activated and contracts. Figure 1 illustrates the sinus node and the components of…

…J point to the onset of the T wave. Because of the long duration of the plateau phase most contractile cells are in this phase…

…and infarction Myocardial ischemia: cellular changes, ECG signs and development of infarction Like all other cells in the human body, cardiac myocytes use ATP (adenosine…

…Vasopressors induce vasoconstriction and increase mean arterial pressure (MAP). Inotropes increase cardiac contractile force (contractility). Several endogenous and synthetic agents exist and are frequently combined…

…Vasopressors induce vasoconstriction and increase mean arterial pressure (MAP). Inotropes increase cardiac contractile force (contractility). Several endogenous and synthetic agents exist and are frequently combined…

…myocardial oxygen requirements, principally through increased heart rate and contractility. In the presence of a flow limiting coronary stenosis, supply cannot increase adequately. Ischaemia begins…

…This makes more calcium available to the contractile proteins which therefore produce stronger contractions. Lowering of the heart rate is due to increased Vagus nerve…

…conduction system allows for rapid spread of the depolarization to the contractile cells. Figure 3 illustrates the components of the conduction system and its temporal…

…excellent, with the vast majority of patients recovering completely after restoration of sinus rhythm (or any other rhythm with normal ventricular rate and activation). Recovery…

…other situations than does ventricular rhythm; idioventricular rhythm is primarily seen after reperfusion in an occluded coronary artery. It also occurs as side effect of…

…moderate ischemia may produce post ischemic stunning. In the absence of infarction, contractile recovery can occur rapidly after reperfusion, with recovery generally occurring within one…

…changes in contractile function, explains the varying ejection fraction. Ejection fraction and left ventricular volume Ejection fraction is also affected by left ventricular volume (size)…

…The action potential in the sinoatrial node and in contractile myocardial cells. Phase 4 of the action potential in the sinoatrial node is called "pacemaker…