Anatomy of the sinoatrial nodal branch in Korean population: imaging with MDCT

Prevalence of anatomic variants in coronary arteries of Japanese Black cattle

Coronary artery anomalies that can cause sudden cardiac death have been described in some mammals. However, few studies have investigated coronary anomalies and coronary artery branching patterns in cattle. Therefore, understanding of bovine coronary arteries is incomplete. The aim of this study was to clarify anatomic variants in coronary arteries of Japanese Black cattle. The gross anatomy of the coronary arteries was examined in the hearts of 100 cattle. A total of 14 of 100 hearts exhibited confirmed coronary anomalies in the left main trunk. These 14 hearts were classified into 5 types potentially associated with cardiac ischemia. Regarding the coronary branches, the subsinuosal interventricular branch originated from the left circumflex branch (LCX) in 98 hearts and from the right coronary artery in 2 hearts. The origin of the sinoatrial nodal branch was classified into 3 types. In 99 hearts, the atrioventricular nodal branch originated from the LCX at the heart crux. This study characterized the prevalence of coronary anomalies, branching patterns of coronary arteries, and coronary artery anatomic variants in Japanese Black cattle.

Anatomical Variations in the Sinoatrial Nodal Artery: A Meta-Analysis and Clinical Considerations

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 of major electronic databases was performed to identify all articles reporting anatomical data on the SANa. No lower date limit or language restrictions were applied. Anatomical data regarding the artery were extracted and pooled into a meta-analysis.

RESULTS

Sixty-six studies (n = 21455 hearts) were included in the meta-analysis. The SANa usually arose as a single vessel with a pooled prevalence of 95.5% (95%CI:93.6-96.9). Duplication and triplication of the artery were also observed with pooled prevalence of 4.3% (95%CI:2.8-6.0) and 0.3% (95%CI:0-0.7), respectively. The most common origin of the SANa was from the right coronary artery (RCA), found in 68.0% (95%CI:55.6-68.9) of cases, followed by origin from the left circumflex artery, and origin from the left coronary artery with pooled prevalence of 22.1% (95%CI:15.0-26.2) and 2.7 (95%CI:0.7-5.2), respectively. A retrocaval course of the SANa was the most common course of the artery with a pooled prevalence of 47.1% (95%CI:36.0-55.5). The pooled prevalence of an S-shaped SANa was 7.6% (95%CI:2.9-14.1).

CONCLUSIONS

The SANa is most commonly reported as a single vessel, originating from the RCA, and taking a retrocaval course to reach the SAN. Knowledge of high risk anatomical variants of the SANa, such as an S-shaped artery, must be taken into account by surgeons to prevent iatrogenic injuries. Specifically, interventional or cardiosurgical procedures, such as the Cox maze procedure for atrial fibrillation, open heart surgeries through the right atrium or intraoperative cross-clamping or dissection procedures during mitral valve surgery using the septal approach can all potentiate the risk for injury in the setting of high-risk morphological variants of the SANa.