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The various courses of the sinoatrial nodal artery (SANa) as seen from a superior view. (A) Retrocaval course; (B) Pericaval course; (C) Precaval course. LA, Left Atrium; RA, Right Atrium; SVC, Superior Vena Cava; Ao, Aorta; P, Pulmonary Trunk; RCA, Right Coronary Artery; LCA, Left Coronary Artery; LCX, Left Circumflex Artery; LAD, Left Anterior Descending Artery; SANa, Sinoatrial Nodal Artery.
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Background and objective:
The sinoatrial nodal artery (SANa) is a highly variable vessel which supplies blood to the sinoatrial node (SAN). Due to its variability and susceptibility to iatrogenic injury, our study aimed to assess the anatomy of the SANa and determine the prevalence of its anatomical variations.
Study design:
An extensive search...
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Citations
... Coronary anatomical variations may characterise this increased occurrence. Despite most patients having sinoatrial and atrioventricular nodal arteries originating from the RCA, coronary arterial dominance may affect their origin, with some arising from the left circulation [6]. Such anatomical variance can expose these vessels to high doses of ACh and subsequent bradyarrhythmias. ...
... The sinoatrial node is located in the wall of the right atrium, in the upper part of the sulcus terminalis at the junction of the superior vena cava and the right atrium, and functions as the pacemaker of the heart (Futami et al. 2003;Kawashima and Sasaki 2003;Standring 2021). The sinoatrial node artery (SANa), an artery whose origin, number, size, and course are reported to be variable, irrigates, among other cardiac structures, the sinoatrial node (Boulemden et al. 2019;Esrailian et al. 2023;Nerantzis et al. 2021;Ortale et al. 2006;Pejković et al. 2008;Shimotakahara et al. 2014;Vikse et al. 2016). As a result, it is clinically relevant, in addition to being anatomically significant, given that it is used as a landmark for the identification of the sinoatrial node (Kawashima and Sasaki 2003;Standring 2021;Vikse et al. 2016). ...
... The sinoatrial node artery (SANa), an artery whose origin, number, size, and course are reported to be variable, irrigates, among other cardiac structures, the sinoatrial node (Boulemden et al. 2019;Esrailian et al. 2023;Nerantzis et al. 2021;Ortale et al. 2006;Pejković et al. 2008;Shimotakahara et al. 2014;Vikse et al. 2016). As a result, it is clinically relevant, in addition to being anatomically significant, given that it is used as a landmark for the identification of the sinoatrial node (Kawashima and Sasaki 2003;Standring 2021;Vikse et al. 2016). In a meta-analysis study published in 2016, Vikse and collaborators concluded that the SANa is more commonly a single vessel, originating from the right coronary artery (RCA), and following more frequently a retrocaval route (Vikse et al. 2016). ...
... As a result, it is clinically relevant, in addition to being anatomically significant, given that it is used as a landmark for the identification of the sinoatrial node (Kawashima and Sasaki 2003;Standring 2021;Vikse et al. 2016). In a meta-analysis study published in 2016, Vikse and collaborators concluded that the SANa is more commonly a single vessel, originating from the right coronary artery (RCA), and following more frequently a retrocaval route (Vikse et al. 2016). When the SANa emerges from the RCA, it tends to arise from its proximal segment (Hutchinson 1978;Sow et al. 1996;Vikse et al. 2016). ...
Several studies reported anatomical variations in the sinoatrial node artery (SANa). Here, we report a rare variation in the origin of the SANa on a human adult male cadaver. During dissection, we identified the SANa originating from a large atrial branch of the right coronary artery (RCA). This branch originates at the level of the inferior border of the heart and courses upwards. The initial part of this vessel is tortuous, and then it follows a straight path parallel to the RCA along the anterior surface of the right atrium. After this part, the artery curves posteriorly and to the left until it reaches the lower border of the right auricle, where it closely approaches the RCA. Finally, the artery runs posteriorly and to the right to follow a course along the medial wall of the right auricle and right atrium to reach a location close to the region of the junction of the superior vena cava and right atrium, where it follows its path buried in the myocardium. After perforating the myocardium, this vessel gives rise to branches that are distributed to both atria in addition to the SANa. The SANa runs to the sinoatrial node in a precaval (anterior to the superior vena cava) course. We also tried to characterize the vessels radiologically. The knowledge of the anatomical variations of the SANa is of the utmost importance for cardiologists and heart surgeons to better understand cardiac disease and accurately plan and execute cardiac interventions and surgical procedures.
... 15 • Origin of the sinoatrial nodal artery: The SANa was seen mostly found to originate from the RCA with a pooled prevalence of 68.0% followed by its origin from the LCx with a pooled prevalence of 22.1%, followed by origin of the artery from the LCA with a pooled prevalence of 2.7%. 15 Other types of rare origin of the SANa such as from the aorta or the bronchial artery were equally rare with a pooled prevalence of 0.3%. When a double origin of the SANa which was rare, when present, the artery most commonly originated from the RCA and LCx with a pooled prevalence of 2.0%. ...
... • Course of the sinoatrial nodal artery: With a pooled prevalence of 47.1%, the retrocaval course of the SANa was the most common course of the artery, followed by the precaval and pericaval courses with a pooled prevalence of 38.9 and 14.0%, respectively. 15 The course of the SANa originating from the LCA or LCx, the retrocaval course of the SANa was also the most common course of the artery with a pooled prevalence of 46.5%. On the contrary, analysis on few other studies reporting the course of the SANa originating from the RCA found the precaval course to be the most common course of the SANa with a pooled prevalence of 43.1%. ...
... On the contrary, analysis on few other studies reporting the course of the SANa originating from the RCA found the precaval course to be the most common course of the SANa with a pooled prevalence of 43.1%. 15 ...
... Given that diastolic dysfunction is associated with increased risk of severe exacerbations, it is possible that impaired left ventricular perfusion increases diastolic dysfunction and increases exacerbation risk (10). Interestingly, the LCx perfuses the sinoatrial (SA) node in up to 25% of individuals (11). ...
Introduction:
In 2019, BLOCK-COPD (Beta-Blockers for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease) evaluated the effect of metoprolol on exacerbation risk and mortality in a COPD population without indications for beta-blocker use. We hypothesized that an imaging metric of coronary artery disease (CAD), the coronary artery calcium (CAC) score, would predict exacerbation risk and identify a differential response to metoprolol treatment.
Methods:
The study population includes participants in BLOCK-COPD from multiple study sites. Participants underwent clinically indicated thoracic CT scan ± 12 months from enrollment. The Weston scoring system quantified CAC. Adjusted Cox proportional hazards models evaluated for associations between CAC and time to exacerbation.
Results:
Data included 109 participants. The mean CAC score was 5.1±3.7, and 92 participants (84%) had CAC scores greater than 0. Over a median (IQR) follow-up time of 350 (280 to 352) days, there were 61 mild exacerbations and 19 severe/very severe exacerbations. No associations were found between exacerbations of any severity and CAC>0 or total CAC. Associations were observed between total CAC and CAC>0 in the LCx and time to exacerbation of any severity (aHR=1.39, CI: 1.08-1.79, p=0.01) and (aHR=1.96, 95% CI: 1.04-3.70, p= 0.04), respectively.
Conclusions:
CAD is a prevalent comorbidity in COPD accounting for significant mortality. Our study confirms high prevalence of CAD using the CAC score; however, we did not discover an association between CAC and exacerbation risk. We did find novel associations between CAC in the LCX and exacerbation risk which warrant further investigation in larger cohorts.
... The sinoatrial node artery (SANa), an artery whose origin, number, size and course are reported to be variable, irrigates, among other cardiac structures, the sinoatrial node. As a result, it is clinically relevant, in addition to being anatomically signi cant, given that it is used as a landmark for the identi cation of the sinoatrial node [4,14,17]. In a meta-analysis study published in 2016, Vikse and collaborators concluded that the SANa is more commonly a single vessel, originating from the right coronary artery (RCA), and follows more frequently a retrocaval route [17]. ...
... As a result, it is clinically relevant, in addition to being anatomically signi cant, given that it is used as a landmark for the identi cation of the sinoatrial node [4,14,17]. In a meta-analysis study published in 2016, Vikse and collaborators concluded that the SANa is more commonly a single vessel, originating from the right coronary artery (RCA), and follows more frequently a retrocaval route [17]. When the SANa emerges from the RCA, it tends to arise from its proximal segment [3,13,17]. ...
... In a meta-analysis study published in 2016, Vikse and collaborators concluded that the SANa is more commonly a single vessel, originating from the right coronary artery (RCA), and follows more frequently a retrocaval route [17]. When the SANa emerges from the RCA, it tends to arise from its proximal segment [3,13,17]. Nevertheless, there are studies reporting an uncommon origin of the SANa from the more distal part of the RCA [2,3,5,7]. An adequate understanding of the normal vascular anatomy and the anatomical variations is vital in several medical specialties so as to accurately perform both a broad range of diagnoses and innumerous medical procedures [7,[12][13][14]17]. ...
Purpose
Several previous studies reported variations in the origin and course of the sinoatrial nodal artery (SANa). In the present report, we describe a rare variation in the origin, course and relations of the SANa.
Methods
The case herein described was found during a routine dissection performed on a formalin-embalmed human adult male cadaver (82 years old).
Results
During the dissection, we identified the SANa originating from the right coronary artery (RCA) at the level of the inferior border (acute margin) of the heart and coursing upward. The initial part of this vessel is tortuous, and then it follows a straight path parallel to the RCA along the anterior surface of the right atrium. After this part, the artery curves posteriorly and to the left until it reaches the lower border of the right auricle, where it closely approaches the RCA. Finally, the artery runs posteriorly and to the right to follow a course along the medial wall of the right auricle and right atrium to reach a location close to the region of the junction of the superior vena cava and right atrium where it follows its path buried in the myocardium. We also characterized the artery radiologically through the injection of a contrast medium into the RCA and in the SANa.
Conclusion
The knowledge of the anatomical variations of the SANa is of the utmost importance for cardiologists and heart surgeons in order to better understand cardiac disease and accurately plan and execute cardiac interventions and surgical procedures.
... Generally, it is possible for either the LCA or the RCA to be dominant, in the sense of giving off the SA nodal artery. Most of the time the right coronary artery is dominant in man (Vikse et al. 2016). The left coronary artery is dominant in the chinchilla, while the sinoatrial nodal artery (SA) is a branch of the right coronary artery. ...
The pattern of normal coronary vascularization in a mammalian heart includes the presence of both right and left coronary arteries. According to the literature data, the presence of single major coronary arteries is mainly related to cardiac abnormalities. Previously it has been reported that the right coronary artery is absent in the coronary vascularization of the heart in the chinchilla. Our research was carried out on thirty chinchillas (Chinchilla laniger Molina). The coronary vessels were filled with colored latex to render them visible. The examinations were supplemented additionally with the use of microcomputed tomography with arterial contrast. Our study demonstrates its undoubtedly presence of the right coronary artery. In all subjects the right coronary artery was present, as was the left coronary artery. Two types of right coronary artery were found. Our results indicate that the normal pattern of coronary vascularization of heart in chinchilla includes both the right and left coronary arteries. An open question remains the presence of single coronary artery is a normal pattern of cardiac arterial vascularization in chinchilla.
... 2 Similarly, the arterial supply to the SN is also varied but typically involves a branch from the right coronary artery in more than half of individuals, the left circumflex in a third, and uncommon branching from the aorta and bronchial arteries in the remainder ( Figure 1). 3,4 As the authors emphasize, regardless of the sinoatrial pattern of origin, most variants involve a course at the atriocaval and aortocaval junction regions, which is the location targeted when the right superior ganglion is ablated. ...
... Although the sinoatrial (SA) node is not anatomically adjacent to the roof of the interatrial septum, the sinoatrial nodal artery (SNA) can be close to this structure due to variations in the course of it. In a meta-analysis conducted by Vikse et al., [2] 68% of SNA originated from the right coronary artery (RCA), and there was a single SNA in 95.5%. In the light of the current data, while the mitral valve is explored, SNA may be damaged due to its course, and rhythm disturbances may occur in the postoperative period. ...
... The origin of SNA was identified from images for each patient considering the variations as described previously. [2] The images of 24 patients could not be achieved. In 17 patients, the origin of the dominant SNA could not be determined. ...
Background: This study aims to investigate the effect of atriotomy approaches applied in mitral valve surgery and variations of the sinoatrial nodal artery on postoperative arrhythmias and the need for a temporary or permanent pacemaker.
Methods: Data of 241 patients (108 males, 133 females, mean age: 53.7±12.3 years; range, 18 to 82 years) who underwent isolated mitral valve surgery with a median sternotomy between January 2009 and December 2019 were retrospectively analyzed. The patients were divided into three groups according to the surgical approach for mitral valve exploration as left atriotomy (n=47), transseptal (n=131), and superior transseptal (n=63). By scanning the hospital records, the origin of the sinoatrial nodal artery was determined in the coronary angiography images obtained before surgery. Postoperative rhythm changes were analyzed based on electrocardiography and telemetry recordings.
Results: Temporary pacing was required in 31 (49.2%) patients in the superior transseptal group, 40 (30.5%) patients in the transseptal group, and 12 (25.5%) patients in the left atriotomy group, indicating a statistically significantly higher rate in the superior transseptal group (p=0.013). Permanent pacemaker implantation was required in only one patient (superior transseptal), indicating no significant difference among the groups. The first-degree atrioventricular block was seen in 28 (44.4%) patients in the superior transseptal group, 42 (32.1%) patients in the transseptal group, and 13 (27.7%) patients in the left atriotomy group (p=0.130). The PR interval in the postoperative period was longer in the superior transseptal group than in the left atriotomy group in patients with the sinoatrial nodal artery originating from the right coronary artery (p=0.049). No significant difference was observed among the surgical approaches regarding the PR interval in patients with the sinoatrial nodal artery originating from the left circumflex coronary artery after surgery.
Conclusion: We believe that the choice of atriotomy in isolated mitral valve surgery and sinoatrial nodal artery variations do not affect permanent arrhythmia alone. Still, the superior transseptal approach causes the electrical conduction to slow down temporarily more than the left atriotomy and transseptal method.
... In this article, we introduced the CATAM rubric and used it to critically appraise a recently published anatomical MA (Kacprzyk et al., 2020). There have been other anatomical MAs recently published (Aldabe et al., 2019;Bellier et al., 2020;Berthaume & Bull, 2021;Cheruiyot et al., 2021;Dreher et al., 2018;Graves et al., 2017;Harvie et al., 2019;Koziej et al., 2020;Morelli et al., 2019;Nallikuzhy et al., 2018;Roberts et al., 2021;Sirico et al., 2019;Solewski et al., 2021;Stefura et al., 2018;Vikse et al., 2016aVikse et al., , 2016bWhitley et al., 2020;Yammine, 2013Yammine, , 2014bYammine, , 2014cYammine, , 2014dYammine et al., 2015;Yurasakpong et al., 2021). We believe that the running paper that we used is an exemplary anatomical MA (Kacprzyk et al., 2020). ...
The hallmark of evidence‐based medicine is the meta‐analysis (MA). For much of its rich history, the field of anatomy has been dominated by descriptive, cadaveric studies. In the last two decades, quantitative measurements and statistical analyses have frequently accompanied such studies. These studies have directly led to the publication of anatomical MAs, which have ushered in the exciting field of evidence‐based anatomy. Although critical appraisal tools exist for clinical MAs, none of them are specifically tailored for anatomical MAs. Therefore, the purpose of this article is to provide a framework by which clinical anatomists and others can critically appraise anatomical MAs using the Critical Appraisal Tool for Anatomical Meta‐analysis (CATAM). Using a running example from a recently published MA, we show how to use the CATAM rubric in a step‐by‐step fashion. Each scored section of the CATAM rubric is summated into a total score (maximum 50 points). This score is then referenced to a conversion chart, which assigns a qualitative value to the MA in a range from “very good” to “poor.” Future studies can investigate the interrater reliability of the instrument, and possibly subject the CATAM rubric to a Delphi panel. As anatomical MAs become more commonplace at surgical grand rounds and journal clubs in academic medical centers throughout the world, we hope that the CATAM rubric can help facilitate meaningful discussions about the quality and clinical relevance of anatomical MAs.
... Deoxygenated blood exits the SAN tissue via venules and specialized Thebesian veins where blood directly enters the right atrial lumen 32 . In humans, the SAN artery has multiple anatomical variations 33 and damage to this artery can be pro-arrhythmogenic 34 . Despite the high metabolic demand of the SAN, a detailed understanding of the vascular network that supports the node for aerobic respiration is limited. ...
The cardiac cycle starts when an action potential is produced by pacemaking cells in the sino-atrial node. This cycle is repeated approximately 100,000 times in humans and 1 million times in mice per day, imposing a monumental metabolic demand on the heart, requiring efficient blood supply via the coronary vasculature to maintain cardiac function. Although the ventricular coronary circulation has been extensively studied, the relationship between vascularization and cellular pacemaking modalities in the sino-atrial node is poorly understood. Here, we tested the hypothesis that the organization of the sino-atrial node micro-vasculature varies regionally, reflecting local myocyte firing properties. We show that vessel densities are higher in the superior versus inferior sino-atrial node. Accordingly, sino-atrial node myocytes are closer to vessels in the superior versus inferior regions. Superior and inferior sino-atrial node myocytes produce stochastic subthreshold voltage fluctuations and action potentials. However, the intrinsic action potential firing rate of sino-atrial node myocytes is higher in the superior versus inferior node. Our data support a model in which the micro-vascular densities vary regionally within the sino-atrial node to match the electrical and Ca2+ dynamics of nearby myocytes, effectively determining the dominant pacemaking site within the node. In this model, the high vascular density in the superior sino-atrial node places myocytes with metabolically demanding, high frequency action potentials near vessels. The lower vascularization and electrical activity of inferior sino-atrial node myocytes could limit these cells to function to support sino-atrial node periodicity with sporadic voltage fluctuations via a stochastic resonance mechanism.
