questions 8

Coronary Artery Anatomy

Topic updated on 12/17/16 3:01pm


  • Right coronary artery (RCA)
    • arises from the right aortic sinus of the ascending aorta
    • passes to the right side of the pulmonary trunk, running in the atrioventricular (coronary) sulcus
    • branches
      • sinoatrial nodal artery
        • supplies the sinoatrial (SA) node
      • right marginal artery
        • supplies the right ventricle
      • posterior descending artery (PDA) aka posterior interventricular artery
        • supplies the right ventricle, posterior interventricular septum (IVS), and left ventricle (minor)
  • Left coronary artery (LCA)
    • arises from the left aortic sinus of the ascending aorta
    • passes to the left side of the pulmonary trunk, running in the atrioventricular (coronary) sulcus
    • branches
      • circumflex artery (CFX)
        • supplies the left atrium and posterior left ventricle
      • left anterior descending artery (LAD) aka anterior interventricular artery
        • supplies the left ventricle (major), right ventricle, and anterior interventricular septum (IVS)
  • Coronary Sinus
    • final endpoint of coronary flow
    • continuous with the right atrium
    • receives the great cardiac vein
    • becomes dilated in chronic pulmonary hypertension 
    • blood in the coronary sinus has the lowest oxygen content in the body with oxygen saturation levels of 30% 
  • Coronary arterial system dominance
    • dominance is defined by which artery gives rise to the PDA that supplies the left ventricle, right ventricle, and posterior interventricular septum
    • right dominance
      • (80%) RCA gives rise to the PDA 
    • left dominance
      • (20%) CFX artery gives rise to the PDA
  • Coronary artery occlusion
    • occlusion most commonly occurs in the anterior interventricular artery (LAD artery)
  • Left atrial enlargement   
    • left atrium is the posterior-most aspect of the heart
      • enlargement compresses posterior structures
        • compression of esophagus → dysphagia
        • compression of left recurrent laryngeal nerve → hoarseness
          • left recurrent laryngeal nerve is a branch of the vagus nerve
  • Coronary steal phenomenon 
    • myocardial ischemia as a result of a narrowing of coronary arteries with subsequent use of a coronary vasodilator
    • results from microvessel dilation "stealing" blood away from other parts of the heart 
    • associated with use of dipyridamole


Qbank (6 Questions)

(M1.CV.1) A 62-year-old Caucasian male presents to the emergency room with severe substernal chest pain, diaphoresis, and nausea. Imaging reveals transmural myocardial infarction in the posterior 1/3 of the ventricular septum. Which of this patient's coronary arteries is most likely occluded? Topic Review Topic

1. Left circumflex
2. Left anterior descending
3. Diagonal perforators
4. Septal perforators
5. Right main

(M1.CV.24) A 49-year-old male presents to the emergency room with dyspnea and pulmonary edema. He reports that he has been smoking 2 packs a day for the past 25 years and has difficulty breathing during any sustained physical activity. His blood pressure is normal, and he reports a history of COPD. An echocardiogram was ordered as part of a cardiac workup. Which of the following would be the most likely finding? Topic Review Topic

1. Aoritc stenosis
2. Mitral valve insufficiency
3. Left ventricular hypertrophy
4. Coronary sinus dilation
5. Tricuspid valve stenosis

(M1.CV.48) A healthy 23-year-old male is undergoing an exercise stress test as part of his physiology class. If blood were to be sampled at different locations before and after the stress test, which area of the body would contain the lowest oxygen content at both time points? Topic Review Topic

1. Superior vena cava
2. Inferior vena cava
3. Coronary sinus
4. Pulmonary artery
5. Pulmonary vein

(M1.CV.150) A 24-year-old man presents to the emergency room with a stab wound to the left chest at the 4th intercostal space. The patient is hemodynamically unstable, and the trauma attending is concerned that there is penetrating trauma to the heart. Which cardiovascular structure is most likely to be affected by such a wound? Topic Review Topic

1. Left atrium
2. Left ventricle
3. Right atrium
4. Right ventricle
5. Aorta

(M1.CV.204) In the coronary steal phenomenon, vessel dilation is paradoxically harmful because blood is diverted from ischemic areas of the myocardium. Which of the following is responsible for the coronary steal phenomenon? Topic Review Topic

1. Venodilation
2. Microvessel dilation
3. Dilation of the large coronary arteries
4. Arterial dilation
5. Volume loss of fluid in the periphery

(M1.CV.4723) A 55-year-old man with a past medical history of hypertension, hyperlipidemia, and insulin dependent diabetes mellitus presents to the ED with a sudden onset of substernal chest pain and pressure that radiated into his neck and down his left arm. The pain started a few hours ago while he was watching television. It was not relieved by rest. He was given aspirin by EMS en route to the hospital. His current medications are glargine insulin, hydrochlorothiazide, and atorvastatin. He has not had any similar episodes previously. His family history is significant an uncle who had a heart attack at age 45. He drinks one drink every other day and has a 25-pack-year smoking history. His temperature is 99.0°F (37.2°C), blood pressure is 150/90 mmHg, pulse is 63/minute, respirations are 22/minute, and point-of-care glucose level is 110 mg/dl. Troponin level is elevated. EKG is shown in image A. What is the most likely etiology of this patient’s presentation? Topic Review Topic
FIGURES: A          

1. Left main coronary artery occlusion
2. Right main coronary artery occlusion
3. Left circumflex artery occlusion
4. Left anterior descending artery occlusion
5. Coronary vasospasm

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Coronary Artery Anatomy

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