Figure 1
Volume rendering
Monocoronary system from non-coronary cusp
SectionCardiovascular
Case TypeAnatomy and Functional Imaging
AuthorsDr. Nicolas Bossu, Dr. Rolf Symons, Prof. Dr. Steven Dymarkowski
Connected authors
51 years, female
Clinical History
The patient was referred by the GP to the ED for thoracic pain irradiating to the left arm.
There were multiple cardiovascular risk factors (arterial hypertension, hypercholesterolaemia, 7 pack-years, positive family history).
A clinical question: Stenosis?
There were multiple cardiovascular risk factors (arterial hypertension, hypercholesterolaemia, 7 pack-years, positive family history).
A clinical question: Stenosis?
Imaging Findings
Rare congenital variant: mono coronary originating from the non-coronary cusp.
The left anterior descending coronary artery (LAD) courses from the right atrioventricular (AV) groove anterior of the pulmonary trunk to the anterior interventricular groove (prepulmonic course).
The left circumflex coronary artery (LCx) courses posterior to the aorta from the right AV groove to the left AV groove (retro-aortic course).
No interatrial "malignant" course. No acute angle takeoff, slitlike orifice nor an intramural segment. No significant coronary stenosis.
The left anterior descending coronary artery (LAD) courses from the right atrioventricular (AV) groove anterior of the pulmonary trunk to the anterior interventricular groove (prepulmonic course).
The left circumflex coronary artery (LCx) courses posterior to the aorta from the right AV groove to the left AV groove (retro-aortic course).
No interatrial "malignant" course. No acute angle takeoff, slitlike orifice nor an intramural segment. No significant coronary stenosis.
Discussion
A. Multiple courses of anomalous origin of the coronary artery from the opposite sinus (ACAOS) are known: retro-aortic, prepulmonic, transseptal and interarterial. [1]
Of these four variants, only the interarterial course is a cause of sudden cardiac death (SCD), the exact pathophysiology is not elucidated, because a normal pulmonary artery is not likely to exert enough pressure to occlude an interarterial coronary artery. [2] Right ACAOS is more frequent than left ACAOS, but has a weaker association with SCD.
An intramural segment, another associated anatomical variant, is probably the most predisposing factor to sudden cardiac death. [3]
It is defined as a proximal segment of the coronary artery located in the 'media' of the aortic wall without an intervening adventitia. [4]
B. Ischaemia (and possibly SCD) occurs when expansion of the great vessels during exercise leads to occlusion of the slitlike ostium and stretching of the acute course of the coronary artery. [2]
The onset of symptoms later in life is related to the development of hypertension, aortic root dilatation and increased stroke volume. [5]
C. Key findings are a slitlike orifice, an acute angle takeoff and a stretched intramural segment.
CT angiography is the examination of choice for detection of an intramural segment due to the multiplanar capabilities. An abnormal elliptical cross section proximally (height-to-width ratio greater than 1,3) with normal round luminal shape more distally allows diagnosis of an intramural segment. [6]
D. In our case biochemistry showed negative troponins and D-dimer tests, ECG showed anteroseptal QS pattern with slight J-point elevation in V1-V3 and echocardiography showed normal LV and RV contractility and function, slight mitral and tricuspid regurgitation.
No arguments for active cardiac ischaemia were retained and low dose acetylsalicylic acid (ASA) was prescribed. Elective CT angiography was planned because of the suspicious symptoms and cardiovascular risk factors. Since there was no malignant course and no coronary calcifications or stenosis, acetylsalicylic acid was ceased. The symptoms were thought to be related to coronary spasm and a calcium channel blocker was prescribed if symptoms would recur.
E. Describe anatomic variants (ACAOS and interarterial course). Search for a slitlike orifice, acute angle of origin and intramural segment because these carry an even higher risk of sudden cardiac death and the latter can be treated with coronary unroofing. [7]
Of these four variants, only the interarterial course is a cause of sudden cardiac death (SCD), the exact pathophysiology is not elucidated, because a normal pulmonary artery is not likely to exert enough pressure to occlude an interarterial coronary artery. [2] Right ACAOS is more frequent than left ACAOS, but has a weaker association with SCD.
An intramural segment, another associated anatomical variant, is probably the most predisposing factor to sudden cardiac death. [3]
It is defined as a proximal segment of the coronary artery located in the 'media' of the aortic wall without an intervening adventitia. [4]
B. Ischaemia (and possibly SCD) occurs when expansion of the great vessels during exercise leads to occlusion of the slitlike ostium and stretching of the acute course of the coronary artery. [2]
The onset of symptoms later in life is related to the development of hypertension, aortic root dilatation and increased stroke volume. [5]
C. Key findings are a slitlike orifice, an acute angle takeoff and a stretched intramural segment.
CT angiography is the examination of choice for detection of an intramural segment due to the multiplanar capabilities. An abnormal elliptical cross section proximally (height-to-width ratio greater than 1,3) with normal round luminal shape more distally allows diagnosis of an intramural segment. [6]
D. In our case biochemistry showed negative troponins and D-dimer tests, ECG showed anteroseptal QS pattern with slight J-point elevation in V1-V3 and echocardiography showed normal LV and RV contractility and function, slight mitral and tricuspid regurgitation.
No arguments for active cardiac ischaemia were retained and low dose acetylsalicylic acid (ASA) was prescribed. Elective CT angiography was planned because of the suspicious symptoms and cardiovascular risk factors. Since there was no malignant course and no coronary calcifications or stenosis, acetylsalicylic acid was ceased. The symptoms were thought to be related to coronary spasm and a calcium channel blocker was prescribed if symptoms would recur.
E. Describe anatomic variants (ACAOS and interarterial course). Search for a slitlike orifice, acute angle of origin and intramural segment because these carry an even higher risk of sudden cardiac death and the latter can be treated with coronary unroofing. [7]
Differential Diagnosis List
Mono coronary originating from the non-coronary cusp without malignant features (SCD)
Right anomalous origin of coronary artery from opposite sinus (ACAOS) with interarterial course without intramural segment
Right anomalous origin from opposite sinus (ACAOS) with interarterial course and intramural segment
Left anomalous origin of coronary artery from opposite sinus (ACAOS) with interarterial course without intramural segment
Left anomalous origin from opposite sinus (ACAOS) with interarterial course and intramural segment
Final Diagnosis
Mono coronary originating from the non-coronary cusp without malignant features (SCD)
References
[1] Angelini P. (2007) Coronary artery anomalies: an entity in search of an identity. Circulation 115(10):1296-1305 (PMID: 17353457)
[2] Chaitman BR, Lespérance J, Saltiel J, Bourassa MG. (1976) Clinical, angiographic, and hemodynamic findings in patients with anomalous origin of the coronary arteries. Circulation 53(1):122-131 (PMID: 1244233)
[3] Lim JC, Beale A, Ramcharitar S. (2011) Anomalous origination of a coronary artery from the opposite sinus. Nat Rev Cardiol 8(12):706-719 (PMID: 21989050)
[4] Topaz O, Edwards JE. (1985) Pathologic features of sudden death in children, adolescents, and young adults. Chest Apr;87(4):476-82. (PMID: 4038935)
[5] Angelini P, Walmsley RP, Libreros A, Ott DA. (2006) Symptomatic anomalous origination of the left coronary artery from the opposite sinus of valsalva. Clinical presentations, diagnosis, and surgical repair. Tex Heart Inst J 33(2):171-179 (PMID: 16878619)
[6] Miller JA, Anavekar NS, El Yaman MM, Burkhart HM, Miller AJ, Julsrud PR. (2012) Computed tomographic angiography identification of intramural segments in anomalous coronary arteries with interarterial course. Int J Cardiovasc Imaging 28(6):1525-1532 (PMID: 21892610)
[7] Agarwal PP, Dennie C, Pena E, Nguyen E, LaBounty T, Yang B, Patel S. (2017) Anomalous Coronary Arteries That Need Intervention: Review of Pre- and Postoperative Imaging Appearances. Radiographics May-Jun;37(3):740-757 (PMID: 28388272)
Case information
| URL: | https://eurorad.org/case/15315 |
| DOI: | 10.1594/EURORAD/CASE.15315 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 2
Maximum intensity projection (MIP)
Monocoronary system originating from the non-coronary cusp.
Figure 3
Axial dataset with 0,6 mm collimation
Play Video
Mono coronary system originating from the non-coronary cusp, no malignant interarterial course nor intramural segment, slitlike orifice or acute angle takeoff predisposing to sudden cardiac death.
Volume rendering
Maximum intensity projection (MIP)
Monocoronary system originating from the non-coronary cusp.
Bossu N, Department of Radiology, University Hospitals Leuven, Leuven, Belgium.
Bossu N, Department of Radiology, University Hospitals Leuven, Leuven, Belgium.