Coupling of the Left Ventricle with the Systemic Circulation
Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos in McDonald's Blood Flow in Arteries, 2022
The function of the left ventricle is to pump blood, so that the tissues of the body may be perfused with nutrients according to their need. Whereas blood flow through the tissues is continuous, or nearly so, the heart’s output is intermittent. The arterial system links the left ventricle to the capillary circulation (Figure 12.1) and thus subserves two functions: first, as a low-resistance conduit and second, as a cushion (or buffer) to flow pulsations at its input (O'Rourke, 1982a, 1982b, 2009a; Taylor, 1967, 1969, 1973). Efficiency of the arterial system is apparent in the tiny mean pressure gradient (normally 1.0 to 3.0 mmHg) over a meter or more between central and peripheral arteries (Pauca et al., 1992) and in the relatively small amount of extra energy (normally around 10 percent of total external work) dissipated in the arterial tree on account of flow pulsations (O'Rourke, 1968; Nichols et al., 1977a; Kelly and Fitchett, 1992) (see Chapter 11). However, both conduit and cushioning functions can be affected by disease—the former by narrowing (and atrophy) of small arteries and arterioles (Laragh and Brenner, 1995) and the latter predominantly by stiffening of the aorta and elastic arteries (Chirinos et al., 2019).
The history of circulation
Dinker B. Rai in Mechanical Function of the Atrial Diastole, 2022
The anatomical structure of the heart was defined by Aristotle and the rest of the stalwarts who followed him continued his teachings. Aristotle defined the heart as hard flesh not easily injured and composed of hard and tense muscular fibers. That definition surpassed all the others. Definitely only two chambers of the heart, the right and left ventricles, corresponded to that description of the heart with the exception of the auricle of the atrium, which appears to be an appendage of the ventricle. The remainder of the atrium did not even come close to it and was never considered to be a functional part of the heart. Sir William Harvey did not devote any importance to the atrial chambers in his theory of the explanation of the motion of blood in the body. He concentrated his efforts solely on the ventricular chambers. He thought of the atria as a storage house for blood. Up to the end of Galen's era, all anatomists believed that the arteries and veins were end vessels and diffused into the tissues.
Thoracic Trauma
Ian Greaves, Keith Porter, Jeff Garner in Trauma Care Manual, 2021
The heart is divided into a right and left side, each with an atrium and a ventricle. The atria act as reservoirs for venous blood, with a small pumping action to assist ventricular filling. The ventricles are the major pumping chambers, delivering blood to the low-pressure pulmonary (right ventricle) and high-pressure systemic (left ventricle) circulations. The cardiac output is the product of the amount of blood ejected from the left ventricle with each beat, multiplied by the heart rate. It is normally about 5 L/min. The heart is surrounded by a double layer of pericardium analogous to the pleurae of the lungs except that the outer fibrous pericardium is unyielding and any collection of pericardial fluid will reduce ventricular filling and decrease cardiac output. This is termed pericardial tamponade.
Effects of cardiac growth on electrical dyssynchrony in the single ventricle patient
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
O. Z. Tikenoğulları, M. Peirlinck, H. Chubb, A. M. Dubin, E. Kuhl, A. L. Marsden
Hypoplastic left heart syndrome (HLHS) is a severe congenital cardiac defect where the left ventricle is underdeveloped and the systemic outflow tract is obstructed (Noonan and Nadas 1958). HLHS occurs in 1.8 of 10,000 live births and represents 3.8% of all patients suffering from congenital heart disease (Ferencz et al. 1985). Without intervention, HLHS is uniformly fatal. Having drastically improved over the past four decades, the current treatment for HLHS – and other functional single right ventricle lesions – involves a series of two (hybrid approach) or three (traditional approach) palliative surgical procedures that establish the Fontan circulation (Fontan and Baudet 1971). In the resulting physiology, the right ventricle is established as the sole ventricular pumping chamber that propels blood through both the systemic and the pulmonary circulations and the venous return is routed directly to the pulmonary arteries. Regardless of the approach, longitudinal data from birth show that only two thirds of the patients born with HLHS today may hope to reach adulthood (Ohye et al. 2016).
Monochorionic Twin Discordance for Horseshoe Lung and Tricuspid Atresia
Published in Fetal and Pediatric Pathology, 2022
Marina Sousa Gomes, José Monterroso, Otília Brandão, Carla Ramalho
Another important aspect to consider in this case is the association between horseshoe lung and tricuspid atresia. In general, the prognosis of horseshoe lung depends on the degree of pulmonary hypoplasia and the severity of associated cardiovascular malformations. Associations between atrioventricular septal defects, tetralogy of Fallot, coarctation of the aorta, patent ductus arteriosus, double inlet left ventricle, persistent left superior cava, and horseshoe lung have been described [3, 4]. In our fetus, the pulmonary horseshoe malformation coexisted with tricuspid atresia, an association not previously described. Tricuspid atresia has no right atrioventricular connection. The prognisis depends on the degree of right ventricle hypoplasia. In this case, there was no ventricular septal defect and the inlet portion of the right ventricle was absent. Consequently, there was a functionally univentricular heart.
Abdominal Ischemia-Reperfusion Induced Cardiac Dysfunction Can Be Prevented by MitoTEMPO
Published in Journal of Investigative Surgery, 2022
Ahmet Akkoca, Murat Cenk Celen, Seckin Tuncer, Nizamettin Dalkilic
In this study, papillary muscles were isolated from the left ventricle of the rat heart for isometric contraction recordings and histological examinations. Under anesthesia, the animals’ rib cages were opened by sternotomy, and hearts were rapidly removed and moved into fresh Krebs solution; having 135 mM NaCl, 5 mM KCl, 2.5 mM CaCl2, 1 mM MgSO4.7H2O, 1 mM NaH2PO4.2H2O, 15 mM NaHCO3, 11 mM glucose, pH adjusted to 7.40, gassed with 95% O2 + 5% CO2 mixture (All chemicals were purchased from Sigma-Aldrich, Germany). In this solution, the hearts were fixed from the right ventricle by a small steel pin in the position visible from the dorsal region, and both atria are separated from the hearts by microsurgical scissors. An incision was made from the level of the atrioventricular valve to the apex on the ventricular wall, and the ventricle was opened to make the papillary muscles visible. Finally, the papillary muscles were isolated by cutting off the connection with the ventricular tissue.
Related Knowledge Centers
- Aorta
- Blood Pressure
- Interventricular Septum
- Pulmonary Circulation
- Atrium
- Lung
- Circulatory System
- Heart
- Blood
- Intraventricular Block