A 63-year-old man presents to the Emergency Department after a fall, and he is found to have a broken hip. He undergoes surgical correction and recovers in the hospital. Before being discharged, he mentions to you that prior to the accident, he had not been able to exercise like before. For the past few months, he has experienced occasional chest pain with exertion that forces him to stop and rest. The pain goes away within 5 minutes of resting.
What should be performed before the patient is discharged from the hospital?
Pharmacologic stress test. Although this is an unusual situation in that this history was not elicited before the patient underwent surgery, the point of the question is to assess the reader’s knowledge on how to evaluate coronary artery disease. When a patient presents with symptoms of angina, it is important to make the diagnosis with a stress test. (B) An exercise stress test with ECG is the most common and preferred method for most patients; for patients that cannot undergo an exercise stress test like this patient with a broken hip, a pharmacologic stress test should be ordered. There are a variety of agents that may be used in this test (regadenoson, dobutamine, adenosine, dipyridamole), and the point is to stress the heart to the degree it would be stressed during exercise and assess for ischemic changes (ST depressions or elevations on ECG).
(C) An echocardiogram might be helpful to assess cardiac function and any valvular abnormalities, but it alone would not help in making the diagnosis of coronary artery disease unless it was done as part of a stress echo (looking for signs of ischemia that manifest as wall motion abnormalities). (D) Coronary angiography is an invasive procedure and may be performed after the stress test if the results are high risk or inconclusive.
A 59-year-old woman presents to your office with chest discomfort, jaw pain, and nausea. The symptoms occurred suddenly 2 hours ago and are getting worse. She has a history of poorly controlled hypertension, and she has a 30 pack-year smoking history. You decide to send her to the Emergency Department and order some initial tests, which are shown below.
An ECG shows multiple T wave inversions and ST depressions in contiguous leads.
Which of the following is the most likely diagnosis?
Non-ST elevation myocardial infarction. It is important to know how to differentiate the types of ACS, since this guides the course of action as well as the prognosis. ACS is made up of unstable angina, non-ST elevation myocardial infarction (NSTEMI), and STEMI. (A, B) Stable angina is not an ACS, and typically occurs with a consistent level of exertion that is relieved with rest and/or nitroglycerin; however, it can progress to unstable angina which typically lasts less than 30 minutes and manifests as angina without exertion, angina with a crescendo pattern, or angina that is severe and of new onset. Any new presentation of typical angina is unstable angina, even if the description sounds like stable angina. (C, D) NSTEMI is differentiated from unstable angina by positive troponins, and STEMI is differentiated from NSTEMI by ST elevations seen on ECG. In unstable angina and NSTEMI, there may or may not be ST depression and T wave inversions (signs of myocardial ischemia), but there will not be ST elevations.
A patient suffers a myocardial infarction and undergoes percutaneous coronary intervention (PCI) with placement of a stent in the left anterior descending coronary artery. Later in the day, the patient develops blue discoloration of several toes on both of his feet. The following day his creatinine increases from 1.2 to 1.8.
Which of the following best represents the mechanism in this situation?
Plaque disruption in the aorta. This is a case of cholesterol embolization syndrome, which is a rare complication of catheterization procedures (in this case, PCI). During PCI, a catheter is usually inserted into the femoral artery and advanced into the proximal aorta where the coronary arteries originate. During this process, disruption of atherosclerotic plaque in the aorta can cause embolization of cholesterol crystals distally. Patients with this syndrome present with multiple areas of ischemia, usually in small, distal vessels. They may also have renal injury and abdominal pain if vasculature to these areas are affected. (B) Given the bilateral description of the findings, plaque rupture and thrombosis in the extremities is unlikely, since this would require that arteries in each extremity undergo the same process simultaneously. This process would also affect larger vascular territories than just the toes. (C) This choice refers to infective endocarditis, which is unlikely given the occurrence right after PCI was performed. (D) Dressler syndrome presents with pericarditis weeks after an MI. (E) Disseminated intravascular coagulation is unlikely given the focal findings in this patient.
A 33-year-old homeless man is brought into the Emergency Department by police after they found him barely arousable on the street next to an empty bottle of vodka. The patient has psychomotor slowing on examination, and a further history cannot be obtained. The ECG technician tells you that the patient has an abnormal heart rhythm.
Atrial fibrillation. Atrial fibrillation is a common arrhythmia, and this patient is at risk from apparent alcoholism. Common causes of atrial fibrillation include hypertension and any underlying heart disease, such as congestive heart failure (CHF), hypertrophic cardiomyopathy, previous myocardial infarction, and anything causing left atrial dilation. A useful mnemonic for remembering some of the causes of atrial fibrillation is PIRATES: Pulmonary disease, Ischemia, Rheumatic heart disease, Atherosclerosis/Atrial myxoma, Thyrotoxicosis, Ethanol, Sepsis. (A) Sinus tachycardia is an abnormal rate (not rhythm), so this does not answer the question. (B, D, E) Heart block, Wolff–Parkinson–White, and torsades de pointes are not nearly as common as atrial fibrillation in the general population or in alcoholics.
A 68-year-old man is brought in by ambulance after losing consciousness. The patient’s wife was with him when he developed crushing chest pain while lying in bed. His wife went to get him some medication for the pain, but when she returned the patient was unconscious. Paramedics were called, and an ECG showed ST elevations in the anterolateral leads. His blood pressure is extremely low, and his extremities are cool. Which of the following best represents the hemodynamics in this type of shock? (Note: CO is cardiac output, JVP is jugular venous pressure, SVR is systemic vascular resistance, and SvO2 is mixed venous oxygen saturation.)
Decreased CO, increased JVP, increased SVR, decreased SvO2. Cardiogenic shock can result from any process leading to ventricular failure, such as myocardial infarction, arrhythmias, acute valvular changes (e.g., acute mitral regurgitation), myocarditis, cardiac contusion, and exacerbated CHF. A decrease in cardiac output will manifest with distended neck veins and cool extremities since peripheral vessels will constrict (increased SVR) to preserve blood pressure. SvO2 indicates the oxygen saturation of hemoglobin in blood returning to the right side of the heart. In most causes of shock the SvO2 will be low due to poor circulatory function and increased tissue extraction of oxygen. SvO2 can be elevated in some forms of distributive shock (e.g., sepsis) due to a high flow state in which there is insufficient time for the peripheral tissues to extract oxygen from the circulating red blood cells. This patient suffered a myocardial infarction that led to cardiogenic shock.
Obstructive shock is a category in which the primary problem is not failure of the heart, but is an obstruction in the circulatory system that disrupts blood flow. Examples include pulmonary embolism, tension pneumothorax, and cardiac tamponade. This will present with the same hemodynamics given in the answer choice for cardiogenic shock; however, the two categories can be differentiated based on the history, physical examination, and other targeted studies.
(A) Examples of distributive shock include sepsis, anaphylaxis, adrenal insufficiency, and spinal cord injury (neurogenic shock). The primary problem in this form of shock is an inability to maintain SVR. The CO may be high initially but then will decrease over time due to cardiac fatigue. (C) In hypovolemic shock, SVR is increased as a response to maintain blood pressure but the CO is normal or low due to the decrease in preload. (D) This scenario could be seen in distributive forms of shock when the heart begins to fail, leading to a decrease in CO and subsequently SvO2 due to slowing of the previously high flow state.
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