From the Guidelines
The ostium of the coronary artery is a critical structure that requires careful evaluation, particularly in the context of anomalous aortic origin of the coronary artery (AAOCA), as its anatomy can significantly impact the risk of sudden cardiac death (SCD) 1. When assessing the ostium, it is essential to consider the anatomy of the coronary ostium and proximal coronary course, as features such as a slit-like or fish-mouth-shaped orifice, acute angle takeoff, intramural course, interarterial course, and hypoplasia of the proximal coronary artery can increase the risk of symptoms, ischemia, and SCD 1. The location of the ostium, whether it is the right coronary artery arising from the left sinus or the left coronary artery arising from the right cusp, also plays a crucial role in determining the risk of SCD, with the latter being more commonly associated with SCD 1. In addition to the anatomy of the ostium, other factors such as age, exercise, and symptoms can also impact the clinical importance of AAOCA and the risk of SCD 1. For example, autopsy series suggest that most patients with AAOCA die during or shortly after exercise, and that ischemia and myocardial fibrosis are common findings in these patients 1. Therefore, understanding the anatomy and clinical significance of the ostium is crucial for diagnosing and treating conditions affecting the coronary arteries and preventing SCD. Key points to consider when evaluating the ostium include:
- Anatomy of the coronary ostium and proximal coronary course
- Location of the ostium (right coronary artery arising from the left sinus or left coronary artery arising from the right cusp)
- Age and exercise habits of the patient
- Presence of symptoms such as chest pain or shortness of breath
- Use of imaging modalities such as echocardiography or MSCT to assess the ostium and proximal coronary artery 1.
From the Research
Ostium Definition and Location
- The ostium is the opening of a coronary artery, with the coronary sinus ostium being a key structure in cardiology 2, 3.
- The coronary sinus ostium is located in the right atrium and serves as the main cardiac vein, playing a crucial role in various cardiac procedures 3.
Anatomical Variations of the Coronary Sinus Ostium
- Studies have shown that there are considerable variations in the diameter of the coronary sinus ostium, with a mean craniocaudal diameter of 8.1 ± 1.51 mm and a mean transverse diameter of 7.67 ± 1.72 mm 3.
- The presence and morphology of the Thebesian valve, which covers the coronary sinus ostium, can also vary significantly, with some hearts having no valve or a remnant valve that covers less than 15% of the ostium 2, 3.
Clinical Importance of the Ostium
- The ostium is a critical structure in cardiology, and its anatomy can influence the haemodynamics of the coronary sinus area 2.
- Knowledge of the anatomical variations of the coronary sinus ostium is essential for overcoming potential difficulties in treating arrhythmias and in cardiosurgery, such as aortic valve replacement and reinsertion of coronary arteries 2, 4.
- Single ostium coronary artery is a rare coronary artery anomaly that can be associated with angina, arrhythmias, and possibly sudden death, making it a clinically important entity to rule out in patients presenting with chest pain 5.
Coronary Artery Ostium and Disease
- Coronary artery dilatation may be due to various aetiologies, including congenital anomalies, atherosclerotic coronary disease, and Kawasaki disease 6.
- Severe dilatation of the coronary artery ostium can be a complication of a sinus of Valsalva aneurysm, highlighting the importance of accurate diagnosis and treatment 6.