Mass General Hospital

Left Main Coronary Artery Arising From the Right Sinus of Valsalva
Ahmed El-Sherief, MD, Richard R. Liberthson, MD, Waleed Ahmed, MD, Carlos A. Rojas, MD, Brian B. Ghoshhajra, MD, MBA, Wilfred S. Mamuya, MD, PhD

Clinical History
A 52-year old man with a history of an atypical chest-pain syndrome underwent coronary angiography, which revealed that his left main coronary artery (LM) arose from the right coronary sinus. He was subsequently referred to the MGH Adult Congenital Heart Service for further evaluation, and an ECG-gated coronary CTA was performed to further delineate his congenital coronary anomaly, and to help guide management.

Figure A: 5mm volume rendered sagittal oblique image demonstrates moderate narrowing of the proximal left lower lobe (LLL) pulmonary artery (PA).
Figure 1
Figure B: 5mm volume rendered sagittal oblique image after percutaneous treatment demonstrates interval expansion of the proximal LLL PA with a patent stent.
Figure 2

(Click on images to enlarge)

Figure 1: Transaxial 5.0 mm maximum intensity projection (MIP) demonstrating that the LM arises from the right coronary cusp with a separate ostium from the RCA, and passes within the myocardium below the pulmonary valve.

Figure 2: Sagittal 1.5 mm MIP demonstrating that the LM (red circle) passes intramuscularly below the level of the pulmonic valve.

Cardiac CTA confirmed that his LM arose from his right coronary cusp, and had a separate ostium from the right coronary artery (RCA). The LM had a short sub-pulmonic course with an intramuscular course, with subsequent emergence  in the proximal anterior interventricular groove to give rise to the left anterior descending artery (LAD) and left circumflex coronary artery.

Congenital coronary artery anomalies are uncommon. Ectopic origin of a coronary artery from the contra-lateral sinus of Valsalva may have important clinical manifestations; most notably exertional sudden cardiac death, particularly in young adults 1, 2, 3. Ectopic origin of a left coronary artery from the right sinus of Valsalva (RSOV) has been particularly noteworthy for its association with sudden cardic death, yet not all patients with this anatomical pattern die suddenly 3.

It is not yet established whether the subgroup of patients with ectopic left coronary artery origin form the RSOV in whom the LM courses within septal musculature as opposed to taking an epicardial course are at a lower risk of sudden cardiac death 3, 4. Our 52 year-old patient, who led a prior physically active lifestyle and has an intramuscular LM course well demonstrated by CTA, is an example of a long-term survivor.

Distinguishing between an inter-arterial course and a myocardial course can be difficult on conventional angiography, and coronary CTA is emerging as the gold-standard in elucidating the origin, the size, the course, and the presence or absence of proximal anatomical or functional obstruction of congenital coronary anomalies 4.  Further observations of these sub-groups of patients by CTA will clarify if indeed there is a differential risk of sudden cardiac death, and the knowledge may have important implications for clinical and management decisions.

1. Liberthson RR, Dinsmore RE, Bharti S, et al. Aberrant coronary artery origin from the aorta. Diagnosis and clinical significance. Circulation. 1974;50:774-779
2. Cheitlin MD, De Castro CM, McAllister HA. Sudden death as a complication of anomalous left coronary origin from the anterior sinus of Valsalva, A not-so-minor congenital anomaly. Circulation. 1974;50:780-787
3. Liberthson, R. Congenital anomalies of the coronary arteries -in -  Diagnosis and management of adult congenital heart disease; 2003: Chapter 48; pg  425-431; Gatzoulis MA, Webb GD and Daubeney PEF, Editors
4. Dodd JD, Ferencik M, Liberthson RR, Cury RC, Hoffmann U, Brady TJ, Abbara S. Congenital Anomalies of Coronary Artery Origin in Adults:64-MDCT Appearance. Am J Roentgenol. 2007 Feb;188 (2):W138-4

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Suhny Abbara, MD
MGH Department of Radiology
Wilfred Mamuya, MD, PhD
MGH Department of Cardiology