The clinical anatomy of the conal artery

Rare origin of the sinoatrial node artery: an anatomic report and a brief review of the literature

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.

Right and Left Coronary and Conus Arteries Originating from Three Separate Ostia in the Right Valsalva Sinus in a Japanese Cadaver: A Case Study with Literature Review

A rare case of an anomalous location of the orifice of the coronary artery was found in a 99-year-old male cadaver undergoing routine dissection. The presence of the right coronary artery (RCA), left coronary artery (LCA), and conus artery (conus branch) originating from the right Valsalva sinus are the characteristic findings of this case. Then, the LCA passed through the aorta and the pulmonary artery. The LCA and RCA branches were normal. These findings are useful for future surgical procedures, including cardiac catheterization.

Prevalence and characteristics of coronary artery fistulas among 20 259 patients undergoing invasive coronary angiography

BACKGROUND

Coronary artery fistula (CAF) is a rare coronary anomaly. This study aimed to investigate the prevalence, clinical features, and imaging characteristics of CAF among patients undergoing coronary angiography (CAG).

METHOD

This was a retrospective study including 20 259 consecutive patients (12 458 were male) who underwent CAG at our institution from September 2018 to March 2023. Electronic angiography records were reviewed, and a total of 86 (0.42%) CAF patients were enrolled and analyzed.

RESULT

Of the 86 CAF patients, 42 (49%) were male. Thus, the prevalence of CAF for males and females was 0.34% and 0.56%, respectively. Arrhythmia, left ventricular (LV) hypertrophy, LV dilation, and LV systolic dysfunction were observed in 38, 25, 10 and 5 cases, respectively. Among the 86 CAF patients, a total of 117 CAFs were detected. 61 (71%) patients had a single CAF, and the remaining 25 (29%) patients had multiple CAFs. Of the 117 CAFs, the most common origins and terminations were the left anterior descending artery (n = 50) and the pulmonary artery (n = 73), respectively. The CAF diameters were greatly varied, ranging from unmeasurable to 7.8 mm, and 22 (18%) CAFs were larger than 3 mm.

CONCLUSION

In the present study, the prevalence of CAF was 0.42% with a female predilection. Arrhythmia, LV remodeling and dysfunction were common. Seventy-one percent of patients had a single CAF. The left anterior descending artery and the pulmonary artery were the most common origin and termination of CAFs, respectively. Most CAFs were small, and 18% of CAFs were larger than 3 mm.

Left Ventricular Summit-Concept, Anatomical Structure and Clinical Significance

The left ventricular summit (LVS) is a triangular area located at the most superior portion of the left epicardial ventricular region, surrounded by the two branches of the left coronary artery: the left anterior interventricular artery and the left circumflex artery. The triangle is bounded by the apex, septal and mitral margins and base. This review aims to provide a systematic and comprehensive anatomical description and proper terminology in the LVS region that may facilitate exchanging information among anatomists and electrophysiologists, increasing knowledge of this cardiac region. We postulate that the most dominant septal perforator (not the first septal perforator) should characterize the LVS definition. Abundant epicardial adipose tissue overlying the LVS myocardium may affect arrhythmogenic processes and electrophysiological procedures within the LVS region. The LVS is divided into two clinically significant regions: accessible and inaccessible areas. Rich arterial and venous coronary vasculature and a relatively dense network of cardiac autonomic nerve fibers are present within the LVS boundaries. Although the approach to the LVS may be challenging, it can be executed indirectly using the surrounding structures. Delivery of the proper radiofrequency energy to the arrhythmia source, avoiding coronary artery damage at the same time, may be a challenge. Therefore, coronary angiography or cardiac computed tomography imaging is strongly recommended before any procedure within the LVS region. Further research on LVS morphology and physiology should increase the safety and effectiveness of invasive electrophysiological procedures performed within this region of the human heart.

The clinical anatomy of high take-off coronary arteries

A number of criteria are used in the literature to describe high take-off coronary arteries, which can in part, explain the divide in the literature on the pathological significance of this anomaly. This study presents the anatomical variations of high take-off coronary arteries to draw attention to the possible clinical implications they may cause during angiography and other surgical procedures. The English Literature was searched to review high take-off coronary arteries. A high take-off coronary artery arising at least 1 cm in adults or 20% the depth of the sinus in children above the sinutubular junction, is considered of greater clinical relevance and was included in our meta-analysis. High take-off coronaries by other criteria was also included as part of the comprehensive review. Exclusion criteria were reports made in case studies or case reviews. The prevalence of high take-off coronary arteries in our study was 26 of 12,899 (0.202%). High take-off coronary arteries were found to originate up to 5 cm above the sinutubular junction. Right coronary arteries made up 84.46% of high take-off coronary arteries reported in the literature. Three (0.023%) cases that originated more than one centimeter above the sinutubular junction was associated with sudden cardiac death. This is a higher reported association than in studies that used other criteria for classification. It is important for clinicians to recognize the importance of correctly diagnosing high take-off coronary arteries in patients with coexisting cardiac morbidities so that suitable management plans can be developed.