A WANDERING CROWN Rami Khouzam, MD Case presentation • 56 yo AAF with no significant PMHx • 2-3 months h/o episodic substernal chest pressure to L arm • Usually related to activity. Resolves with rest or SL NTG • + DOE • One episode at night woke her up • Has been told in the past that her EKG is normal and that the pain is d.t. anxiety Medications: • SL NTG (recently started) • ASA & CaCO3 Family Hx: • No h / o heart disease • + for HTN, DM Social Hx: • Remote tobacco user • Denies drugs PE • Neck: No JVD. No bruits • CVS: RR, normal S1 & S2; +S4; no S3 , m or r ; PMI non-displaced • Lungs: CTA bilaterally • Ext: No e, c, c • Labs: Normal • CXR: Normal • EKG: NSR; flattened T’s in III, aVF and V3-V6 EKG Echocardiogram • • • • • • Normal chamber size & dimension Normal LV Systolic fn. EF: 55-60% Mild concentric LVH Trace MR, Mild TR Normal IVC No pulmonary HTN Cardiac catheterization • L Main: Normal • LAD: Normal • L Cx: Normal • RCA: Unsuccessful engagement. Aortic root angiogram: probable anomalous origin from left coronary cusp Cath ETT • Exercise time: 7:06 min, Mets: 8.7 • Chest Pain • 1 mm inferolateral ST depression • Clinically & EKG’ly positive • • • • • • • Anatomy of Normal Coronary Arteries Anomalous origin of Coronary Arteries Embryology Pathophysiologic mechanisms Clinical presentation Diagnostic modalities Treatment Definitions of the word “Corona” in Webster’s Dictionary Corona: (latin) A crown or something like a crown In Anatomy • “The Upper part of tooth” • “A Skull” In Astronomy “A circle of light around the sun or the moon; the halo around the sun during a total eclipse” In Botany “The cuplike part of the inner side of the corolla of certain flowers” In Electricity “A sometime visible electric discharge around a conductor at high potential” In my fellowship And the MOST famous Corona of them all... Number and size of coronary ostia • Normally an individual has 2 or sometimes 3 coronary ostia • Conal branch of the RCA may arise separately from the right sinus • The Cx or LAD may, on occasion, arise directly from the aortic root/ Absent Lt. Main Anomalous pulmonary origins of the coronaries (APOC) Anomalous aortic origins of the coronaries (AAOC) Congenital atresia of the left main coronary artery (CALM) Coronary arteriovenous fistulae (CAVF) Coronary artery bridging (CB) Coronary artery aneurysm Coronary stenosis Frequency • In the US: Coronary arteries anomalies are observed in: – 0.3-1.3% of patients undergoing diagnostic coronary angiography – 1% of routine autopsy examinations – in 4-15% of young people who experience sudden death Coronary Artery Anomalies A review of more than 10,000 patients from the Clayton Cardiovascular Labs Charles Wilkins, et al. Texas Heart Institute Journal 1988;15:166-73 Aanomalous Origin & Course… Incidence 1- Cx from RCA or right sinus of Valsalva: the most common: 0.48 % 2- Both coronary arteries from left sinus of Valsalva: 0.28 %: reported in 1982 by Roberts et al 3- Both coronary arteries from right sinus of Valsalva: 0.06-0.19 % 4- Single coronary artery: 0.06 % 5- LAD from RCA or right sinus of Valsalva: first reported in 1966 by Jokl et al. Course is important - Anterior to pulmonary trunk - Posterior to aorta - Within intraventricular septum - Between aorta & pulmonary trunk Development of the coronary vessel system Circ. Res. 2002;91:761-768 David E. Reese Not everyone has coronary vessels • Not all organisms with a heart have coronary vessels • Invertebrates DO NOT have coronaries (seastar, jellyfish, worms…) • Among the vertebrates: Most amphibians; newts, salamanders and bullfrogs have no coronary vessels • In fish (the last vertebrate class), the presence of coronary vessels is variable • Larger fast-swimming fish have extensive coronary vessels • Most other vertebrates; mammals, reptiles and avians have complete coronary systems • Dependance on pulmonic respiration and the lack of cutaneous respiration • Complete anatomical separation of left (oxygenated) and right (deoxygenated) sides of the heart – The use of circulating luminal blood to deliver oxygen to the right ventricle is impossible – Thick-walled ventricle that can’t be served by simple gas diffusion from the myocardium to the heart lumen • An alternative method of delivery, presumably the coronary system was necessitated Development of the coronary vessels • Complex vasculogenic process that begins after heart looping • Coronary vasculogenesis: regulated by myocardium, but also dependent on epicardium and its precursor, the proepicardial organ, for the provision of coronary vascular progenitor cells Origin of Cells that make up the Heart • • • • • Cardiac myocytes Endocardial endothelium Fibroblasts Vascular smooth muscle Vascular endothelium The Decision to make Arteries & Veins, Remodeling, and Making the final connection to systemic circulation • Several molecules play a role in the diversification of vessels • Further growth ; complex process of angiogenesis, vascular remodeling, and arterialization of specific branches gives rise to the definitive coronary system • The initial phases of coronary vasculogenesis proceed in the absence of blood flow caliber governed by forces other than blood flow • The final connection to the Aorta involves local apoptotic events that eventually lead to the melding of coronary endothelia with that of the aorta (Unique) • The origins of the coronary arteries to the aorta and the connection of the coronary sinus to the right atrium occur in different regions of the heart • How do these 2 vessel systems run parallel on the surface of the heart but diverge to make connections to the systemic circulation? • Considering the acrobatic nature of this developmental system, it should not be surprising that errors occur Cellular precursors of the coronary arteries • EPDCs (Epicardial derived cells) might be found to have a competence similar to that shown by the recently discovered bipotential vascular progenitors cells, which are able to differentiate into endothelium or smooth muscle depending on their exposure to VEGF or PDGF-BB Tex Heart Inst J. 2002; 29 (4): 243-249 • Vascular endothelial growth factor (VEGF) • Both VEGFR-2 and R-3 may play a role in the formation of the coronary artery roots Tomanek RJ - Dev Dyn - 01-NOV-2002;225(3):233-40 Intimal preatherosclerosis thickening of the coronary arteries in human fetuses of smoker mothers J Thromb Haemost. 2003 Oct;1(10):2234-8 Matturri L Preatherosclerotic intimal alterations of the coronary arteries are already detectable in the prenatal period and are significantly associated with maternal cigarette smoking Anomalous Coronary Artery from the opposite sinus: Pathophysiologic Mechanisms as documented by IVUS The Journal of Invasive Cardiology, Sept 2003 Paolo Angelini, et al. 1- Tangential origination with a proximal intramural course lateral compression of the lumen outward displacement of the inner (more than the outer) layer of the aortic wall. Phasically accentuated during late systole and early diastole. On IVUS: intramural segment: area reduction of 22 % to 69 % • Young athletes CO from 5 L/min at rest (HR 70, SV 71) to ~ 25 L/min during exercise (HR 200, SV 125) significantly aortic wall stress while expanding aortic dimensions • As the aorta and pulmonary artery become larger with late childhood, compression obstructs the blood flow in this aberrant coronary • The expected in aortic compliance with aging could contribute to ACAOS more benign prognosis in older patients 2- Spasm of ostium and/or proximal ectopic coronary artery (slit-like or hypoplastic ostium) 3- Clot formation 4- Aortopulmonary scissors effect: Influence exerted entirely by aorta ? (pulmonary a. pressure much lower than c.a pressure, & less or not likely to cause coronary luminal collapse) 5- Aortic hinge effect (acute angle of take-off) • 68 % had associated CAD (> 50 % luminal stenosis of 1 or more vs. ) • 19 % had cardiac abnormalities other than CAD Symptoms & Signs: • Asymptomatic • Symptoms in < 30 %: - Palpitation - DOE - Angina ( in older patients) - Syncope - Fatigue - Sudden death (in younger patients) Imaging Studies (non-invasive) • Transthoracic echocardiography TTE • Transesophageal echocardiography TEE • Electron beam computed tomography EBCT • Multidetector computer tomography MDCT • Magnetic resonance imaging MRI TEE • Intermediate course between the aorta & PA: - Predominant systolic flow pattern • Anomalous LM coursed anterior to the pulmonary trunk: - Predominant diastolic flow pattern J Am Soc Echocardiogr 2003;16(12) Visualization of coronary artery anomalies and their anatomic course by contrast-enhanced electron beam tomography and three-dimensional reconstruction The American Journal of Cardiology (Volume 87. Number 2. Jan.15, 2001) Dieter Ropers, MD Germany EBCT • Very high temporal resolution • No mechanical parts are involved in image acquisition • Instead, X-ray are created by an electron beam, which sweeps across fixed tungesten targets arranged in a semicircular manner around the patient Dieter Ropers,Germany Am J Cardiology 2001;87(2) • One high resolution image acquired in 50 to 100 ms • Slice thickness is 1.5 or 3.0 mm, (triggered by the EKG images acquired up to 5 times within one cardiac cycle) 7 to 9 line pairs per cm MDCT • X-ray gantry rotation time of 500 ms or less • Images free of motion artifact • Stimultaneous data acquisition in 16 parallel cross-sections with collimations of less than 1 mm • 9 line pairs per cm • Sensitivity of EBCT: 74% - 92% with specificities 66% - 94% • Sensitivity of MDCT: 72% - 95% with specificities 84% - 97% • Slow heart rate is a prerequisite 60 - 65 • ß-receptor-blocking • Definitive diagnosis: selective arterial angiography • (Swan-Ganz) catheter to guide assessment of the course of the anomalous vessels is recommended Treatment Surgery is the only definitive treatment of coronary artery anomalies • The surgical techniques evolved over the last 5 decades • 178 patients, Texas Heart Institute from December 1963 through June 2001 • 15 patients underwent surgery for AAOC A ) RCA from the left sinus of Valsalva • Reimplantatoin of the anomalous coronary artery to the ipsilateral sinus of Valsalva • Ligation of the anomalous artery and bypass with a saphenous vein graft • (RIMA) without ligation of the RCA 2 ) LCA or circumflex branch originated from the right sinus of Valsalva • Bypass grafting with anastomosis od the LIMA to the LAD artery • RIMA graft to the circumflex branch • Saphenous vein graft to the circumflex branch • No deaths, follow-up coronary angiography showed no graft failure • Surgical indications for AAOC are more controversial • Some authors advocate the use of internal mammary arteries because of their long-term patency advantage over vein grafts • Others advocate the use of vein grafts to avoid the early occlusion and stenosis that can occur in arterial grafts that are used to bypass vessels with competetive flow • Another difficult decision whether to ligate a patent anomalous artery in order to eliminate competitive flow • Many efforts have been made to noninvasively image the coronary arteries using magnetic resonance, electron beam computed tomography, and recently multidetector computed tomography (MDCT) • A new generation of MDCT scanners with arrays of detectors, a higher temporal an spatial resolution Monarchies of the World • There are ~ 225 inhabited countries and territories in the world • 47 countries (~ < 1/4) are monarchies Moral of the Story Well-deserved Royalty: Not just to have a crown….but to have a well-fitting ONE!