CORONARY ANOMALIES. Clinical Significance. Disclosures. Definitions. Learning Objectives. Prevalence. Consultant for M2S, Inc.

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1 Disclosures CORONARY ANOMALIES Consultant for M2S, Inc. Julianna M. Czum, MD Director, Division of Cardiothoracic Imaging Department of Radiology Dartmouth Hitchcock Medical Center Assistant Professor of Radiology and Medicine, Section of Cardiology Geisel School of Medicine at Dartmouth Learning Objectives 1. To identify and discuss imaging features of coronary artery anomalies. 2. To recognize which coronary artery anomalies are more likely to be clinically significant. Definitions Normal variant An alternative, relatively unusual morphologic feature seen in greater than 1% of the population Anomaly A morphologic feature rarely encountered (<1%) in the general population Prevalence Clinical Significance Autopsy: <1% Benign Malignant Coronary Catheterization: 1% Congenital Heart Disease: 2% Normal Variant Potentially Fatal Coronary CT Angiography: 5% Silent Arrhythmia Ischemia Sudden Death 1

2 Coronary Anomalies 80% Benign Asymptomatic 20% Malignant Potentially lethal Risk of ischemia and sudden cardiac death Compromised blood flow at rest or during exercise Classification of Coronary Anomalies Number Origin Course Termination Coronary anomalies are present in >30% of sudden non traumatic deaths in teens/young adults. Anomalies of Number Normal number of coronary arteries (ostia): 2 Multiple ostia: 3 or 4 Separate origin conus branch (11.6%) Separate origin of sinus node branch (0.2%) Absent L main, i.e. separate origin of LAD & LCX Anomalous: 1 (single coronary artery) Duplication Examples of Normal Variants Left main trifurcation with ramus intermedius branch Separate conus branch arising from the right sinus of Valsalva? Anomaly due to multiple ostia Multiple Ostia Duplication Absent left main Separate origins of LAD and LCX Dual LAD Young PM, et al. AJR 2011;197: Shikri JE, et al. RadioGraphics 2012; 42:

3 Single coronary artery Single coronary artery Anomalies of Origin with or without Abnormal Proximal Course 1. Ectopic/high origin 2. Ostial stenosis 3. From wrong SOV 4. From pulmonary artery Normal: Coronary Artery Origins Upper 1/3 of SOV Abnormal: Near aortic valve commissures High/ectopic takeoff: 6% May have a long intramural course Usually does not reduce diastolic blood flow Usually not symptomatic RCA origin from the tubular portion of the ascending aorta, i.e. above the sinotubular junction Ostial stenosis Acute angle origin through the aortic wall Membrane or fibrotic ridge Intramural course (deep to adventitia) Cross section: lentiform (or slit like ) rather than round Can occur with anomalous coronary: RCA from L SOV & interarterial course Angelini P. Am Heart J 1989; 117:

4 Intramural tunneling of proximal high origin RCA Origin from Wrong Sinus of Valsalva 1. Prepulmonic course (Anterior to RVOT) A 2. Interarterial course (Between arteries) C 3. Transseptal course (through Crista) 4. Retroaortic course (Dorsal to aortic root) D B Origin from Wrong Sinus of Valsalva Prepulmonic Prepulmonic A Interarterial Transseptal B C Retroaortic D Retroaortic Retroaortic 4

5 Malignant : Risk for sudden death Interarterial Dynamic Compression of RCA Interarterial: Anomalous Right Coronary from Left Cusp Acute angle of ostium, intramural, and/or compression Young PM, et al. AJR 2011;197: Interarterial: Anomalous Left Coronary from Right Cusp Transseptal hammock Coronary Origin from Pulmonary Artery Coronary Origin from Pulmonary Artery ALCAPA: Anomalous LCA from PA ( Bland Garland White syndrome ) 1/300,000 live births Untreated: 90% die within 1 year Shunt with steal phenomenon: LCA flow reversal Ischemia, MI, CHF Pena E, et al. RadioGraphics 2009;29:

6 Normal Origin and Termination, but Abnormal Course: Myocardial Bridging Myocardial bridging, also known as intramyocardial tunneling Abnormal course: Mid LAD dives into LV myocardium Re emerges in epicardial fat Prevalence: reported 15 85% (?!) Myocardial Bridge 80%: Incidental, superficial 20%: Deeper, >2.3 mm below surface; potentially significant Rare: Spasms versus systolic narrowing causes ischemia If symptomatic, stress testing appropriate If hemodynamically significant, surgical treatment consists of unroofing myotomy Incomplete Myocardial Bridge, or Superficial Tunneling Complete Myocardial Bridge, or Deep Tunneling Coronary Fistula Normal Origin Affected vessel usually dilated and tortuous from increased flow Abnormal Termination Anywhere other than myocardium Chamber (coronary cameral fistula) Vessel (coronary vessel name fistula): vena cava, coronary sinus, etc Single or multiple connections Normal Origin, but Abnormal Termination: Coronary Fistula Rare: % Symptoms depend on: Shunt volume: most commonly L to R Steal phenomenon leading to ischemia: stress test 6

7 RCA to SVC fistula RCA to SVC fistula 46 year old male with thrombosed calcified LCFlx to coronary sinus fistula Associations Coronary anomalies found more often in association with congenital heart disease than in the general population, especially with: Transposition of the great arteries Tetralogy of Fallot 17 year old male, D TGA s/p Senning Clinical Significance Benign Malignant D TGA Single origin coronary artery Acute angle take off LAD with proximal inter arterial course L Circumflex arises from RCA with retroaortic course Intramyocardial tunneling mid LAD Normal Variant Silent Arrhythmia Ischemia Potentially Fatal Sudden Death 7

8 Management Based Classification 1. Surgical (almost) definite 2. Surgical possible 3. Surgeon awareness 4. Cardiologist awareness Clinical Classification Surgical (almost) definite : refer to surgery Shunts: ALCAPA (anom. pulmonary origin) Coronary fistula (anom. termination) Wrong sinus coronary origin: LM or LAD from R SOV with interarterial course Clinical Classification Surgical possible : stress test for perfusion abnormalities in symptomatic patients Wrong sinus coronary origin: RCA from L SOV with interarterial course Myocardial bridge: unroofing Intramural coronary origin: unroofing Clinical Classification Surgeon awareness : potential injury during cardiac surgery Wrong sinus coronary origin: prepulmonic or retroaortic, e.g. valve replacement High origin above sinotubular ridge: e.g. cross clamp for CABG Clinical Classification Cardiologist awareness : coronary ostial cannulation during catheter based angiography Additional ostia: Separate origin conus artery Absent left main with separate origins of LAD and LClfx High origin above sinotubular junction References 1. Shriki JE, Shinbane JS, Rashid MA, et al. Identifying, characterizing, and classifying congenital anomalies of the coronary arteries. RadioGraphics 2012;32: Young PM, Gerber TC, Williamson EE, et al. Cardiac Imaging: Part 2, Normal, variant, and anomalous configurations of the coronary vasculature. AJR 2011;197: