Functions of the Cardiovascular System
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2020
The left coronary artery arises from the posterior aortic sinus and supplies blood to the left ventricle and left atrium. The left main coronary divides into branches: The left anterior descending artery branches off the left coronary artery and supplies blood to the front of the left side of the heart. It passes along the anterior interventricular groove towards the apex, turns round the inferior border of the heart and anastomoses with the posterior interventricular artery.The circumflex artery branches off the left coronary artery and encircles the heart muscle around the left heart border to anastomose with the posterior interventricular artery. This artery supplies blood to the left atrium and the side and back of the left ventricle.
SBA Answers and Explanations
Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury in SBAs for the MRCS Part A, 2018
The heart is composed of cardiac muscle. This cardiac muscle receives the oxygen and nutrients that it requires to pump effectively through the coronary arteries. There are two principal coronary arteries: the right and the left. The right coronary originates from the anterior aortic sinus, whereas the left coronary artery originates from the left posterior aortic sinus. The left coronary artery divides into an anterior interventricular (or left anterior descending) artery and circumflex branches. The right coronary gives off the posterior interventricular (posterior descending) artery. The right coronary supplies the right atrium and part of the left atrium, the SA node in 60 per cent of cases, the right ventricle, the posterior part of the interventricular septum, and the AV node in 80 per cent of cases. The left coronary artery supplies the left atrium, left ventricle, anterior interventricular septum, SA node in 40 per cent of cases, and AV node in 20 per cent of cases.
The Cardiovascular System
Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard in Toxicologic Pathology, 2018
Nutritional blood supply to the heart is delivered by two major arteries: the right and left coronary arteries. These arteries arise from behind the left and right cusps of the aortic valve at the sinuses of Valsalva at the base of the aorta. The arteries tend to form a ring or crown as they encircle the base of heart in the AV or coronary groove. The left coronary artery gives rise to the left descending and left circumflex coronary arteries. The epicardial coronary arteries give rise to the intramural arteries that penetrate the myocardium. The arteries radiate over the entire heart, and in the subepicardium, give rise to perforating intramyocardial arteries that provide the nutritional blood supply to a rich capillary bed and within the capillary bed there are extensive anastomoses that often run parallel to the cardiac myocytes, and this is very evident on cross section where a 1:1 ratio of capillaries to cardiac myocytes can be seen (Maxie and Robinson 2007).
Giant right coronary artery aneurysm fistulising to the superior vena cava
Published in Acta Cardiologica, 2021
Luis E. Lezcano-Gort, Zineb Kounka, Imara Herrera-Denis, Benjamín Roque-Rodríguez, María V. Mogollón-Jiménez, Sergio Moyano-Calvente
A 78-year-old woman was referred to our service by her primary care physician with exertional chest pain, progressive dyspnoea, and a heart murmur. Her medical record was relevant for hypertension, dyslipidemia, and permanent atrial fibrillation. Physical examination revealed a loud continuous murmur at the left sternal border. On transthoracic echocardiography, unusual flow originating from the right sinus of Valsalva was noted, and confirmed with transesophageal echocardiography (Figure 1(A)). Coronary angiography showed normal left coronary artery, and selective catheterisation of the right coronary artery was not successful. However, this artery was filled from the left coronary artery. Aortography revealed a giant para-aortic aneurysm (Figure 1(B)). Oximetry showed increased oxygen saturation at the lower end of the superior vena cava, and the QP/QS ratio was calculated at 3.5:1. Computed tomography scan with 3D volume-rendering reconstruction showed a giant aneurysm (diameter 7 cm) arising from the proximal segment of the right coronary artery, and fistulising to the superior vena cava (Figure 1(C–E)). Surgical intervention successfully resected the aneurysm and closed the fistula (Figure 1(F)).
Platelet adhesion potential estimation in a normal and diseased coronary artery model: effects of shear stress magnitude versus shear stress history
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Coronary heart disease (CHD) claims the most lives in the United States annually and accounts for more than 50% of all cardiovascular associated deaths (Lloyd-Jones et al. 2010). It has previously been shown that biochemical and mechanical factors play a role in CHD development, including high plasma cholesterol and altered shear stress (Schwenke and Carew 1989b, Schwenke and Carew 1989a; Cunningham and Gotlieb 2005). The coronary arteries are common sites for altered shear stress due to the complex three dimensional geometry of the vessels (Dodge Jr. et al. 1992). Furthermore, the left coronary artery is a common site for atherosclerotic lesion growth, which alters the normal blood flow to such a significant extent that the flow becomes pathological. During most CHDs, not only are mechanical cues altered but biological cues can also be modified. One common observation due to these altered cues is that there is an increase in the adhesion between platelets and endothelial cells, two salient cells for CHD. Many groups have shown that endothelial cell and platelet functions, including adhesion, are altered under disturbed blood flow conditions (Chien 2008; Rubenstein and Yin 2010; Yin et al. 2011). However, these functional changes are generally not included in numerical models of cardiovascular diseases. Therefore, it is important to develop an accurate predictive model of platelet and endothelial cell functional changes in response to altered shear stress in the left coronary artery.
Left Main Coronary Artery Embolism after Transcatheter Aortic Valve Replacement: Insights from Multimodal Intracoronary Imagings
Published in Structural Heart, 2018
Yuki Katagiri, Kazumasa Yamasaki, Takashi Ueda, Manabu Misawa, Takashi Ota, Yoshinobu Onuma, Shigeru Saito, Seiji Yamazaki
Although cases of LMCA occlusion likely caused by a leaflet tissue during TAVR procedures have already been reported,1 this is the first documentation of the embolized mass by OCT. The OCT finding suggested a tissue could be a mixture of calcification and lipid, which can be regarded as a part of leaflet of aortic valve.2 Protection of left coronary artery in advance prompted a successful treatment without any hemodynamic disturbance. Such dislocated and mobile tissue may become present at any phase during the procedure (i.e. after insertion of the wire into the left ventricle, after pre-dilatation, or during implantation of the valve), a caution should be drawn in imaging findings during procedure.
Related Knowledge Centers
- Aorta
- Aortic Arch
- Aortic Valve
- Cardiac Muscle
- Coronary Arteries
- Heart Valve
- Left Anterior Descending Artery
- Circumflex Branch of Left Coronary Artery
- Coronary Catheterization
- Autopsy