Snapshot A 70-year-old man presents to the emergency room with chest pain for the past hour. He has a medical history of coronary artery disease, hyperlipidemia, and type 2 diabetes mellitus. He has a 30-pack-year smoking history and drinks alcohol regularly. His electrocardiogram reveals ST-segment elevations in leads V3 and V4. Aspirin is given and he is rushed for an angioplasty. (Myocardial infarction with left main coronary artery involvement) Anatomy Coronary arteries include right coronary artery (RCA) arises from right aortic sinus supplies right ventricle and His bundle branches sinoatrial nodal artery supplies the sino-atrial (SA) node right marginal artery supplies the right ventricle posterior descending artery (PDA) supplies AV node (supplied by atrioventricular nodal artery) posterior portion of interventricular septum and ventricles posteromedial papillary muscle left main coronary artery (LCA) arises from left aortic sinus branches left circumflex coronary artery (LCX) supplies lateral and posterior wall of left ventricle anterolateral papillary muscle supplies some blood flow to SA node and AV node left anterior descending artery (LAD) supplies anterior portion of the interventricular septum anterolateral papillary muscle anterior surface of the left ventricle most common artery to be involved in myocardial infarction Coronary arterial system dominance defined by which artery supplies the PDA right dominance 85% of cases RCA gives rise to PDA left dominance 8% of cases LCX gives rise to PDA codominance 7% of cases both LCX and RCA give rise to PDA Coronary sinus the endpoint of coronary flow and is continuous with the right atrium in chronic pulmonary hypertension, coronary sinus becomes dilated blood in the coronary sinus has the lowest oxygen content in the body oxygen saturation levels 30% Left atrium most posterior part of the heart enlargement can compress the esophagus, causing dysphagia the left recurrent laryngeal nerve, causing hoarseness Localization of Myocardial Infarctions (MI) Leads with ST-Segment Elevation Location of MI Vessel(s) Affected V1-V2 Septal LAD V3-V4 Anterior LAD V5-V6 Apical LAD, LCX, or RCA I and aVL Lateral LCX V7-V9 Posterior RCA and LCX II, III, and aVF Inferior RCA and LCX Pathology Coronary steal phenomenon myocardial ischemia narrowed coronary arteries are dilated maximally to increase blood flow to ischemic tissues when a vasodilator is used, coronary arteries that are not narrowed vasodilate narrowed coronary arteries cannot further dilate thus, blood flow is stolen from the narrowed arteries classically, dipyridamole is associated with this also used for cardiac stress testing
QUESTIONS 1 of 10 1 2 3 4 5 6 7 8 9 10 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.CV.17.4723) 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 for 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 Figure A. What is the most likely etiology of this patient’s presentation? QID: 108549 FIGURES: A Type & Select Correct Answer 1 Left main coronary artery occlusion 12% (28/243) 2 Right main coronary artery occlusion 30% (73/243) 3 Left circumflex artery occlusion 15% (37/243) 4 Left anterior descending artery occlusion 38% (93/243) 5 Coronary vasospasm 1% (3/243) M 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.CV.13.150) A 24-year-old man presents to the emergency room with a stab wound to the left chest at the sternocostal junction at the 4th intercostal space. The patient is hemodynamically unstable, and the trauma attending is concerned that there is penetrating trauma to the heart as. Which cardiovascular structure is most likely to be injured first in this stab wound? QID: 100666 Type & Select Correct Answer 1 Left atrium 6% (5/81) 2 Left ventricle 23% (19/81) 3 Right atrium 4% (3/81) 4 Right ventricle 62% (50/81) 5 Aorta 4% (3/81) M 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept (M1.CV.13.204) 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? QID: 100720 Type & Select Correct Answer 1 Venodilation 3% (2/74) 2 Microvessel dilation 46% (34/74) 3 Dilation of the large coronary arteries 30% (22/74) 4 Arterial dilation 18% (13/74) 5 Volume loss of fluid in the periphery 1% (1/74) M 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept (M1.CV.13.48) 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? QID: 100564 Type & Select Correct Answer 1 Superior vena cava 4% (19/488) 2 Inferior vena cava 12% (60/488) 3 Coronary sinus 32% (156/488) 4 Pulmonary artery 42% (203/488) 5 Pulmonary vein 7% (34/488) M 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept (M1.CV.13.1) 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? QID: 100803 Type & Select Correct Answer 1 Left circumflex 17% (16/96) 2 Left anterior descending 5% (5/96) 3 Diagonal perforators 2% (2/96) 4 Septal perforators 4% (4/96) 5 Right main 72% (69/96) M 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept (M1.CV.12.24) 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? QID: 100540 Type & Select Correct Answer 1 Aortic stenosis 11% (9/79) 2 Mitral valve insufficiency 25% (20/79) 3 Left ventricular hypertrophy 38% (30/79) 4 Coronary sinus dilation 15% (12/79) 5 Tricuspid valve stenosis 6% (5/79) M 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept
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