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Question 1
Incorrect
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A 25-year-old is brought into the emergency department after being discovered unresponsive in a neighbor's backyard. It is suspected that the patient had consumed alcohol at a nearby club and opted to walk home in the snowy conditions. The patient's temperature is documented as 27.8ºC. The nurse connects leads to conduct a 12-lead ECG. Which of the subsequent ECG alterations is most closely linked to hypothermia?
Your Answer: Prominent U waves
Correct Answer: Osborn waves
Explanation:Hypothermia can cause various changes in an electrocardiogram (ECG). These changes include a slower heart rate (bradycardia), the presence of Osborn Waves (also known as J waves), a prolonged PR interval, a widened QRS complex, and a prolonged QT interval. Additionally, the ECG may show artifacts caused by shivering, as well as the presence of ventricular ectopics. In severe cases, hypothermia can lead to cardiac arrest, which may manifest as ventricular tachycardia (VT), ventricular fibrillation (VF), or asystole.
Further Reading:
Hypothermia is defined as a core temperature below 35ºC and can be graded as mild, moderate, severe, or profound based on the core temperature. When the core temperature drops, the basal metabolic rate decreases and cell signaling between neurons decreases, leading to reduced tissue perfusion. This can result in decreased myocardial contractility, vasoconstriction, ventilation-perfusion mismatch, and increased blood viscosity. Symptoms of hypothermia progress as the core temperature drops, starting with compensatory increases in heart rate and shivering, and eventually leading to bradyarrhythmias, prolonged PR, QRS, and QT intervals, and cardiac arrest.
In the management of hypothermic cardiac arrest, ALS should be initiated with some modifications. The pulse check during CPR should be prolonged to 1 minute due to difficulty in obtaining a pulse. Rewarming the patient is important, and mechanical ventilation may be necessary due to stiffness of the chest wall. Drug metabolism is slowed in hypothermic patients, so dosing of drugs should be adjusted or withheld. Electrolyte disturbances are common in hypothermic patients and should be corrected.
Frostbite refers to a freezing injury to human tissue and occurs when tissue temperature drops below 0ºC. It can be classified as superficial or deep, with superficial frostbite affecting the skin and subcutaneous tissues, and deep frostbite affecting bones, joints, and tendons. Frostbite can be classified from 1st to 4th degree based on the severity of the injury. Risk factors for frostbite include environmental factors such as cold weather exposure and medical factors such as peripheral vascular disease and diabetes.
Signs and symptoms of frostbite include skin changes, cold sensation or firmness to the affected area, stinging, burning, or numbness, clumsiness of the affected extremity, and excessive sweating, hyperemia, and tissue gangrene. Frostbite is diagnosed clinically and imaging may be used in some cases to assess perfusion or visualize occluded vessels. Management involves moving the patient to a warm environment, removing wet clothing, and rapidly rewarming the affected tissue. Analgesia should be given as reperfusion is painful, and blisters should be de-roofed and aloe vera applied. Compartment syndrome is a risk and should be monitored for. Severe cases may require surgical debridement of amputation.
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This question is part of the following fields:
- Cardiology
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Question 2
Correct
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A 28-year-old woman comes in with a one-week history of occasional dizzy spells and feeling generally under the weather. She experienced one brief episode where she fainted. She was diagnosed with systemic lupus erythematosus four months ago and has been prescribed high-dose ibuprofen. During the examination, she has swelling in her hands and feet but no other notable findings. Her EKG shows broad QRS complexes and tall peaked T waves.
Which ONE blood test will confirm the diagnosis?Your Answer: Urea and electrolytes
Explanation:This patient’s ECG shows signs consistent with hyperkalemia, including broad QRS complexes, tall-peaked T waves, and bizarre p waves. It is estimated that around 10% of patients with SLE have hyperkalemia, which is believed to be caused by hyporeninemic hypoaldosteronism. Additionally, the patient has been taking a high dose of ibuprofen, which can also contribute to the development of hyperkalemia. NSAIDs are thought to induce hyperkalemia by reducing renin secretion, leading to decreased potassium excretion.
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This question is part of the following fields:
- Cardiology
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Question 3
Incorrect
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While examining a 68-year-old man, you detect an ejection systolic murmur. The murmur does not radiate, and his pulse character is normal.
What is the SINGLE most likely diagnosis?Your Answer: Physiological murmur
Correct Answer: Aortic sclerosis
Explanation:Aortic sclerosis is a condition that occurs when the aortic valve undergoes senile degeneration. Unlike aortic stenosis, it does not result in any obstruction of the left ventricular outflow tract. To differentiate between aortic stenosis and aortic sclerosis, the following can be used:
Feature: Aortic stenosis
– Symptoms: Can be asymptomatic, but may cause angina, breathlessness, and syncope if severe.
– Pulse: Slow rising, low volume pulse.
– Apex beat: Sustained, heaving apex beat.
– Thrill: Palpable thrill in the aortic area can be felt.
– Murmur: Ejection systolic murmur loudest in the aortic area.
– Radiation: Radiates to carotids.Feature: Aortic sclerosis
– Symptoms: Always asymptomatic.
– Pulse: Normal pulse character.
– Apex beat: Normal apex beat.
– Thrill: No thrill.
– Murmur: Ejection systolic murmur loudest in the aortic area.
– Radiation: No radiation. -
This question is part of the following fields:
- Cardiology
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Question 4
Correct
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A 55-year-old woman comes in with severe chest pain in the center of her chest. Her ECG reveals the following findings:
ST elevation in leads I, II, aVF, and V6
Reciprocal ST depression in leads V1-V4 and aVR
Prominent tall R waves in leads V2-V3
Upright T waves in leads V2-V3
Based on these findings, which blood vessel is most likely affected in this case?Your Answer: Right coronary artery
Explanation:This ECG indicates changes that are consistent with an acute inferoposterior myocardial infarction (MI). There is ST elevation in leads I, II, aVF, and V6, along with reciprocal ST depression in leads V1-V4 and aVR. Additionally, there are tall dominant R waves in leads V2-V3 and upright T waves in leads V2-V3. Based on these findings, the most likely vessel involved in this case is the right coronary artery.
To summarize the vessels involved in different types of myocardial infarction see below:
ECG Leads – Location of MI | Vessel involved
V1-V3 – Anteroseptal | Left anterior descending
V3-V4 – Anterior | Left anterior descending
V5-V6 – Anterolateral | Left anterior descending / left circumflex artery
V1-V6 – Extensive anterior | Left anterior descending
I, II, aVL, V6 – Lateral | Left circumflex artery
II, III, aVF – Inferior | Right coronary artery (80%), Left circumflex artery (20%)
V1, V4R – Right ventricle | Right coronary artery
V7-V9 – Posterior | Right coronary artery -
This question is part of the following fields:
- Cardiology
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Question 5
Incorrect
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A 32-year-old woman comes to the Emergency Department complaining of dizziness and palpitations. She informs you that she was recently diagnosed with type A Wolff-Parkinson-White syndrome. You proceed to perform an ECG.
Which of the following ECG characteristics is NOT observed in type A Wolff-Parkinson-White (WPW) syndrome?Your Answer: Shortened PR interval
Correct Answer: Predominantly negative QRS complexes in leads V1 and V2
Explanation:Wolff-Parkinson-White (WPW) syndrome is a condition that affects the electrical system of the heart. It occurs when there is an abnormal pathway, known as the bundle of Kent, between the atria and the ventricles. This pathway can cause premature contractions of the ventricles, leading to a type of rapid heartbeat called atrioventricular re-entrant tachycardia (AVRT).
In a normal heart rhythm, the electrical signals travel through the bundle of Kent and stimulate the ventricles. However, in WPW syndrome, these signals can cause the ventricles to contract prematurely. This can be seen on an electrocardiogram (ECG) as a shortened PR interval, a slurring of the initial rise in the QRS complex (known as a delta wave), and a widening of the QRS complex.
There are two distinct types of WPW syndrome that can be identified on an ECG. Type A is characterized by predominantly positive delta waves and QRS complexes in the praecordial leads, with a dominant R wave in V1. This can sometimes be mistaken for right bundle branch block (RBBB). Type B, on the other hand, shows predominantly negative delta waves and QRS complexes in leads V1 and V2, and positive in the other praecordial leads, resembling left bundle branch block (LBBB).
Overall, WPW syndrome is a condition that affects the electrical conduction system of the heart, leading to abnormal heart rhythms. It can be identified on an ECG by specific features such as shortened PR interval, delta waves, and widened QRS complex.
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This question is part of the following fields:
- Cardiology
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Question 6
Incorrect
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A 72 year old male is brought to the emergency department by his daughter due to sudden confusion, severe headache, and problems with coordination. Upon initial assessment at triage, the patient's blood pressure is found to be significantly elevated at 224/126 mmHg. You suspect the presence of hypertensive encephalopathy. What is the primary treatment option for this condition?
Your Answer: Glyceryl trinitrate
Correct Answer: Labetalol
Explanation:The primary treatment option for hypertensive encephalopathy, a condition characterized by sudden confusion, severe headache, and coordination problems due to significantly elevated blood pressure, is labetalol.
Further Reading:
A hypertensive emergency is characterized by a significant increase in blood pressure accompanied by acute or progressive damage to organs. While there is no specific blood pressure value that defines a hypertensive emergency, systolic blood pressure is typically above 180 mmHg and/or diastolic blood pressure is above 120 mmHg. The most common presentations of hypertensive emergencies include cerebral infarction, pulmonary edema, encephalopathy, and congestive cardiac failure. Less common presentations include intracranial hemorrhage, aortic dissection, and pre-eclampsia/eclampsia.
The signs and symptoms of hypertensive emergencies can vary widely due to the potential dysfunction of every physiological system. Some common signs and symptoms include headache, nausea and/or vomiting, chest pain, arrhythmia, proteinuria, signs of acute kidney failure, epistaxis, dyspnea, dizziness, anxiety, confusion, paraesthesia or anesthesia, and blurred vision. Clinical assessment focuses on detecting acute or progressive damage to the cardiovascular, renal, and central nervous systems.
Investigations that are essential in evaluating hypertensive emergencies include U&Es (electrolyte levels), urinalysis, ECG, and CXR. Additional investigations may be considered depending on the suspected underlying cause, such as a CT head for encephalopathy or new onset confusion, CT thorax for suspected aortic dissection, and CT abdomen for suspected phaeochromocytoma. Plasma free metanephrines, urine total catecholamines, vanillylmandelic acid (VMA), and metanephrine may be tested if phaeochromocytoma is suspected. Urine screening for cocaine and/or amphetamines may be appropriate in certain cases, as well as an endocrine screen for Cushing’s syndrome.
The management of hypertensive emergencies involves cautious reduction of blood pressure to avoid precipitating renal, cerebral, or coronary ischemia. Staged blood pressure reduction is typically the goal, with an initial reduction in mean arterial pressure (MAP) by no more than 25% in the first hour. Further gradual reduction to a systolic blood pressure of 160 mmHg and diastolic blood pressure of 100 mmHg over the next 2 to 6 hours is recommended. Initial management involves treatment with intravenous antihypertensive agents in an intensive care setting with appropriate monitoring.
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This question is part of the following fields:
- Cardiology
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Question 7
Correct
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You evaluate a 45-year-old Asian man with a heart murmur. During auscultation, you observe a loud first heart sound and a mid-diastolic murmur at the apex. Upon examination, you observe that he has plum-red discoloration of his cheeks.
What is the SINGLE most probable diagnosis?Your Answer: Mitral stenosis
Explanation:The clinical symptoms of mitral stenosis include shortness of breath, which tends to worsen during exercise and when lying flat. Tiredness, palpitations, ankle swelling, cough, and haemoptysis are also common symptoms. Chest discomfort is rarely reported.
The clinical signs of mitral stenosis can include a malar flush, an irregular pulse if atrial fibrillation is present, a tapping apex beat that can be felt as the first heart sound, and a left parasternal heave if there is pulmonary hypertension. The first heart sound is often loud, and a mid-diastolic murmur can be heard.
The mid-diastolic murmur of mitral stenosis is a rumbling sound that is best heard at the apex, in the left lateral position during expiration, using the bell of the stethoscope.
Mitral stenosis is typically caused by rheumatic heart disease, and it is more common in females, with about two-thirds of patients being female.
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This question is part of the following fields:
- Cardiology
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Question 8
Correct
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You are summoned to a cardiac arrest in the resuscitation area of your Emergency Department.
Which ONE statement about the utilization of amiodarone in cardiac arrest is accurate?Your Answer: It increases the duration of the action potential
Explanation:Amiodarone is a medication that is recommended to be administered after the third shock in a shockable cardiac arrest (Vf/pVT) while chest compressions are being performed. The prescribed dose is 300 mg, given as an intravenous bolus that is diluted in 5% dextrose to a volume of 20 mL. It is important to note that amiodarone is not suitable for treating PEA or asystole.
In cases where VF/pVT persists after five defibrillation attempts, an additional dose of 150 mg of amiodarone should be given. However, if amiodarone is not available, lidocaine can be used as an alternative. The recommended dose of lidocaine is 1 mg/kg. It is crucial to avoid administering lidocaine if amiodarone has already been given.
Amiodarone is classified as a membrane-stabilizing antiarrhythmic drug. It works by prolonging the duration of the action potential and the refractory period in both the atrial and ventricular myocardium. This medication also slows down atrioventricular conduction and has a similar effect on accessory pathways.
Additionally, amiodarone has a mild negative inotropic action, meaning it weakens the force of heart contractions. It also causes peripheral vasodilation through non-competitive alpha-blocking effects.
It is important to note that while there is no evidence of long-term benefits from using amiodarone, it may improve short-term survival rates, which justifies its continued use.
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This question is part of the following fields:
- Cardiology
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Question 9
Correct
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A 62 year old female presents to the emergency department 1 hour after experiencing intense tearing chest pain that radiates to the back. The patient reports the pain as being extremely severe, rating it as 10/10. It is noted that the patient is prescribed medication for high blood pressure but admits to rarely taking the tablets. The patient's vital signs are as follows:
Blood pressure: 188/92 mmHg
Pulse rate: 96 bpm
Respiration rate: 23 rpm
Oxygen saturation: 98% on room air
Temperature: 37.1ºC
What is the probable diagnosis?Your Answer: Aortic dissection
Explanation:The majority of dissections happen in individuals between the ages of 40 and 70, with the highest occurrence observed in the age group of 50 to 65.
Further Reading:
Aortic dissection is a life-threatening condition in which blood flows through a tear in the innermost layer of the aorta, creating a false lumen. Prompt treatment is necessary as the mortality rate increases by 1-2% per hour. There are different classifications of aortic dissection, with the majority of cases being proximal. Risk factors for aortic dissection include hypertension, atherosclerosis, connective tissue disorders, family history, and certain medical procedures.
The presentation of aortic dissection typically includes sudden onset sharp chest pain, often described as tearing or ripping. Back pain and abdominal pain are also common, and the pain may radiate to the neck and arms. The clinical picture can vary depending on which aortic branches are affected, and complications such as organ ischemia, limb ischemia, stroke, myocardial infarction, and cardiac tamponade may occur. Common signs and symptoms include a blood pressure differential between limbs, pulse deficit, and a diastolic murmur.
Various investigations can be done to diagnose aortic dissection, including ECG, CXR, and CT with arterial contrast enhancement (CTA). CT is the investigation of choice due to its accuracy in diagnosis and classification. Other imaging techniques such as transoesophageal echocardiography (TOE), magnetic resonance imaging/angiography (MRI/MRA), and digital subtraction angiography (DSA) are less commonly used.
Management of aortic dissection involves pain relief, resuscitation measures, blood pressure control, and referral to a vascular or cardiothoracic team. Opioid analgesia should be given for pain relief, and resuscitation measures such as high flow oxygen and large bore IV access should be performed. Blood pressure control is crucial, and medications such as labetalol may be used to reduce systolic blood pressure. Hypotension carries a poor prognosis and may require careful fluid resuscitation. Treatment options depend on the type of dissection, with type A dissections typically requiring urgent surgery and type B dissections managed by thoracic endovascular aortic repair (TEVAR) and blood pressure control optimization.
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This question is part of the following fields:
- Cardiology
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Question 10
Correct
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A 32-year-old woman comes to the Emergency Department complaining of dizziness and palpitations. She informs you that she was recently diagnosed with Wolff-Parkinson-White syndrome. She is connected to an ECG monitor, and you observe the presence of an arrhythmia.
What is the most frequently encountered type of arrhythmia in Wolff-Parkinson-White syndrome?Your Answer: Atrioventricular re-entrant tachycardia
Explanation:Wolff-Parkinson-White (WPW) syndrome is a condition that affects the electrical system of the heart. It occurs when there is an abnormal pathway, known as the bundle of Kent, between the atria and the ventricles. This pathway can cause premature contractions of the ventricles, leading to a type of rapid heartbeat called atrioventricular re-entrant tachycardia (AVRT).
In a normal heart rhythm, the electrical signals travel through the bundle of Kent and stimulate the ventricles. However, in WPW syndrome, these signals can cause the ventricles to contract prematurely. This can be seen on an electrocardiogram (ECG) as a shortened PR interval, a slurring of the initial rise in the QRS complex (known as a delta wave), and a widening of the QRS complex.
There are two distinct types of WPW syndrome that can be identified on an ECG. Type A is characterized by predominantly positive delta waves and QRS complexes in the praecordial leads, with a dominant R wave in V1. This can sometimes be mistaken for right bundle branch block (RBBB). Type B, on the other hand, shows predominantly negative delta waves and QRS complexes in leads V1 and V2, and positive in the other praecordial leads, resembling left bundle branch block (LBBB).
Overall, WPW syndrome is a condition that affects the electrical conduction system of the heart, leading to abnormal heart rhythms. It can be identified on an ECG by specific features such as shortened PR interval, delta waves, and widened QRS complex.
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This question is part of the following fields:
- Cardiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
