Fundamentals of cardiac electrophysiology
Ever D. Grech in Practical Interventional Cardiology, 2017
The coronary sinus extends from the inferior right atrial (RA) septum along the inferior mitral annulus. It has a muscular coat in its proximal course and transitions to the great cardiac vein that continues laterally and superiorly that is marked on the endovascular surface by the valve of Vieussen.6 The great cardiac vein lies alongside the left circumflex artery and continues to become the anterior interventricular vein that runs parallel to the left anterior descending coronary artery. Lateral left ventricular (LV) branches join the coronary sinus at various levels and are potential targets for placement of pacing leads for LV epicardial pacing. The middle cardiac vein is a proximal branch of the coronary sinus that runs in the posterior interventricular grove, parallel to the posterior descending coronary artery. Ablation of some posterior septal accessory pathways is possible from within this branch but runs the risk of inadvertent thermal damage to adjacent branches of the right coronary artery.
Coronary Circulation
Lara Wijayasiri, Kate McCombe, Paul Hatton, David Bogod in The Primary FRCA Structured Oral Examination Study Guide 1, 2017
Describe the coronary circulation. The arterial blood supply to the heart comes from the right coronary artery (RCA) and the left coronary artery (LCA), which arise from the anterior and posterior aortic sinuses respectively.The RCA supplies the right atrium, right ventricle, sinoatrial node and, in 90% of people, also the atrioventricular node.The LCA divides into the left anterior descending (LAD) artery and the left circumflex (LCx) artery and supplies the left atrium, left ventricle and most of the interventricular septum.In 30% of the population the LCA and RCA supply equal proportions of blood while in 50% the RCA is the dominant vessel.Venous drainage occurs predominantly via the coronary sinus. This receives blood from the great cardiac vein (draining the anterior aspect of the heart) and the middle cardiac vein (draining the posterior aspect of the heart). In addition, there are other vessels that drain directly into the heart chambers including the thebesian veins, which contribute towards true shunt.
Specialization in individual circulations
Neil Herring, David J. Paterson in Levick's Introduction to Cardiovascular Physiology, 2018
About 95% of the coronary venous blood returns through the coronary sinus, which runs in the posterior AV groove and receives blood from the great cardiac vein (anteriorly), posterior lateral cardiac veins and middle cardiac vein (from the inferior interventricular groove) and then drains into the right atrium (Figure 1.4). Posterior lateral cardiac veins and branches of the middle cardiac vein are common sites for placement of left ventricular pacing leads of cardiac resynchronization pacemakers and defibrillators (see Chapter 18.5). The rest drains into the cardiac chambers through the anterior coronar y and Thebesian veins. Some Thebesian veins drain into the left side of the heart, contributing to the slight deoxygenation of arterial blood (saturation ~97%). The coronary circulation is the shortest in the body, with a mean transit time of only 6-8 s in a resting human.
Coronary Sinus Defect, Premature Restriction of Foramen Ovale and Cysto-Colic Peritoneal Band
Published in Fetal and Pediatric Pathology, 2023
The coronary sinus is the most constant feature of the cardiac venous system [16–18], and of all of the branches of the coronary venous system, the great cardiac and middle cardiac vein [19] and posterior cardiac veins are the ones present most consistently [17]. Many of the these major cardiac veins anastomose and two rather constant venous anastomotic rings have been described [17]. The larger and more constant anastomotic ring (90%) connects the ends of the middle and great cardiac veins and the less constant (70%) ring connects the ends of the posterior and left marginal veins with a branch of the middle cardiac vein [17]. All the major veins also receive inconstant albeit innumerable, smaller branches, which contribute to an anastomotic network of veins in the epicardium [17]. Without the persistent left superior vena cava and left hypoplastic heart and in the absence of coronary sinus, it is tempting to speculate that the direct drainage of the major cardiac veins and their anastomotic channels into the left heart may have contributed to hemodynamic forces potentiating the closure of the foreman ovale (Fig. 2).
Coronary sinus ostial atresia with persistent left superior vena cava on cardiac computed tomography
Published in Acta Cardiologica, 2021
Shu Yoshihara, Taku Yaegashi, Masaki Matsunaga, Masaaki Naito
A 61-year-old man who had a history of hypertrophic cardiomyopathy with atrial tachyarrhythmia was referred for cardiac computed tomography (CCT) before scheduled electrophysiology studies. CCT showed coronary sinus (CS) atresia of the right atrial ostium in the crux cordis area which communicated with a persistent left superior vena cava (PLSVC; Figure 1(A,B,E)). The right SVC drained normally into the right atrium (RA; Figure 2(A,B)). In addition, two aberrant veins were found. First, tortuous vessels of 3 mm in diameter arose from the CS at separate points, then joined together and terminated into the left atrium (LA) (Figure 1(A,C,E) arrowheads). Second, a vessel of 2 mm in diameter arose from the middle cardiac vein (MCV), coursed in the right atrioventricular groove along the right coronary artery, and terminated into the inferior side of the RA (Figure 1(D,E) arrows). Atresia of the CS ostium with a PLSVC was diagnosed. Other congenital cardiac anomalies were not found.
Diagnosis and treatment of the rare procedural complication of malpositioned pacing leads in the left heart: a single center experience
Published in Scandinavian Cardiovascular Journal, 2022
Rasmus Borgquist, Maiwand Farouq, Hanna Markstad, Johan Brandt, David Mörtsell, Steen Jensen, Uzma Chaudhry, Lingwei Wang
In order for a lead to end up in the left side of the heart, it must either be introduced directly into the arterial circulation or pass from the venous to the arterial side through the atrial or ventricular septum or exit the right atrium into the CS. Risk factors for MPL include abnormal thoracic anatomy, underlying congenital heart disease, and operator inexperience (<100 implants) [1]. With experience, implanters are usually able to distinguish aberrant lead courses on fluoroscopy during the primary implant. Placing the RV lead in the middle cardiac vein is probably not uncommon in patients with a large CS ostium, but can easily be recognized by checking the position using fluoroscopy in a left anterior oblique (LAO) or left lateral projection, and observing the lead movement pattern (absence of tricuspid valve dislocation of the lead). The most common lead course to the inside of the LV is through a PFO or a small ASD. This may be more difficult to diagnose during implant, but again, fluoroscopy in the LAO or left lateral projection will reveal a more posterior leftward-oriented lead location.
Related Knowledge Centers
- Great Cardiac Vein
- Ventricle
- Heart
- Posterior Interventricular Sulcus
- Coronary Sinus