Case-based MCQ

Explanation: Correct Answer Is C Exercise-associated postural hypotension Pathophysiology Cessation of exercise results in sudden decrease in venous return to the heart (preload) Manifestations Athlete collapses immediately after cessation of exercise No loss of consciousness Dizziness or lightheadedness Normal to minimally elevated core temperature Management Trendelenburg positioning (ie, feet inclined above the head) Oral hydration This patient who collapsed after running a marathon but did not lose consciousness most likely has exercise-associated postural hypotension (EAPH). EAPH is thought to occur due to physiologic adaptations in endurance athletes, who have significantly higher cardiac output than unconditioned individuals due to hypertrophy and hyperplasia of the left ventricle (ie, athlete’s heart).  During strenuous exercise, skeletal muscles, particularly in the lower extremities, exert significant pressure on the venous system, which increases venous return to the heart.  When an athlete abruptly stops exercising (eg, finishes a marathon), the muscles are no longer exerting pressure, and venous return dramatically decreases.  The sudden decrease in cardiac preload fails to meet increased cardiac demand and results in transient postural hypotension and collapse.  This condition may be compounded by inhibition of the baroreflex and dehydration, which often occur with intense exercise. Unlike many other causes of exercise-associated collapse (eg, exertional heat stroke, sweat-induced hyponatremia), patients with EAPH remain alert with normal mental status.  Collapse or inability to walk is typically associated with a sensation of lightheadedness or dizziness.  Core temperature may be normal or mildly elevated (as in this patient) from prolonged exercise.  Management of EAPH is primarily supportive; patients should be placed in Trendelenburg position and offered oral hydration. Although severe asthma exacerbations can cause tachypnea, and hypoxia or hypercarbia may result in altered mentation with collapse, patients are expected to develop severe dyspnea and wheezing. Cardiac arrhythmia is a rare but potentially fatal cause of collapse in athletes.  However, cardiac arrhythmia typically occurs during exercise, not immediately afterward; patients may lose consciousness (unlike this patient who collapsed without losing consciousness); and arrhythmia would not explain the patient’s inability to stand or walk. Exertional heat stroke presents with elevated core temperature (>40C) associated with altered mental status (eg, confusion, syncope, seizure).  Although this patient’s core temperature is mildly elevated, his mental status is normal, making this diagnosis unlikely. Exertional hyponatremia results from excessive fluid intake (weight gain).  It presents with confusion, headache, and swollen hands after prolonged heat exposure during an athletic event; a resultant seizure may induce collapse.  This patient’s normal mental status and consciousness make this diagnosis unlikely. Exercise-associated postural hypotension occurs in conditioned athletes and is caused by the sudden decrease in venous return after cessation of exercise, which fails to meet increased cardiac demand.  It is characterized by collapse (with no loss of consciousness) immediately after completion of exercise.

A 39-year-old man is brought to the emergency department after immediately collapsing at the finish line when he completed a marathon.  Although he was unable to stand or walk, the patient did not lose consciousness.  He says he has run multiple marathons in the past without any problems.  Medical history includes mild intermittent asthma.  He uses albuterol as needed and last took it a week ago.  Temperature is 38 C, blood pressure is 98/52 mm Hg, pulse is 118/min, and respirations are 22/min.  The patient is alert and oriented and does not report any pain.  Neurologic examination is normal.  Which of the following is the most likely cause of this patient’s collapse? A. Acute severe asthma exacerbation B. Cardiac arrhythmia C. Exercise-associated postural hypotension D. Exertional heat stroke E. Exertional hyponatremia

Correct Answer Is D This patient’s acute-onset pleuritic chest pain, hemoptysis, and tachycardia are suggestive of pulmonary embolism (PE).  Hemoptysis is a result of pulmonary infarction.  Low-grade fever and mild leukocytosis may also occur with PE.  This patient’s risk factors for venous thromboembolism include HIV and hemoconcentration due to dehydration in the setting of a recent gastrointestinal illness. Chest CT scan shows the characteristic wedge-shaped, pleural-based opacification that is likely to occur distal to a completely occluded pulmonary artery.  Pulmonary infarct areas may also occasionally be seen on chest x-ray as a Hampton hump.  An associated pleural effusion is often present on the same side as the infarct (ie, exudative effusion resulting from infarction-induced inflammation).  On contrast-enhanced CT scan, the PE itself will appear as a pulmonary artery filling defect. Bacterial pneumonia presents with rapidly progressing chest pain, fevers, chills, cough, and dyspnea.  Alveolar infiltrates may be seen on chest x-ray and CT scan but are not typically wedge-shaped as they follow bronchial rather than vascular distribution.  Symptom onset is less likely to be as dramatic, and hemoptysis can occur but is uncommon. Lung cancer can cause cough, chest pain, dyspnea, and hemoptysis.  However, symptoms are generally gradually progressive and imaging is more likely to show a discrete, spiculated mass rather than a peripheral, wedge-shaped lesion. Pneumocystis pneumonia is a common cause of dyspnea in patients with HIV/AIDS.  However, it typically occurs in patients with CD4+ counts <200/mm3 and tends to be subacute in presentation.  Imaging commonly shows a diffuse interstitial pattern. Although patients with HIV are at increased risk for pulmonary tuberculosis, this woman has a recent negative PPD, and the classic cavitary lesions are not seen (a false-negative PPD is unlikely in a patient with a CD4+ count of 350/mm3).  In addition, pulmonary tuberculosis does not typically cause wedge-shaped lesions. Pulmonary emboli classically present with sudden-onset pleuritic chest pain, cough, and dyspnea.  Hemoptysis can occur as a result of pulmonary infarction.  Chest CT scan showing a peripheral, wedge-shaped infarction is virtually pathognomonic for pulmonary embolism.

A 34-year-old woman comes to the emergency department after noticing hemoptysis.  Yesterday, the patient developed sudden-onset right-side chest pain and mild dyspnea while getting out of bed.  For the last 4 days, she has had diarrhea as well as nausea and vomiting after eating in a new restaurant.  The patient feels weak and thought her respiratory symptoms were due to being in bed and inactive.  Her chest pain increases with deep breathing.  Her other medical problems include HIV, heroin use, and a prior episode of cellulitis on the right arm.  The patient’s last CD4+ cell count 2 months ago was 350/mm3, and PPD at that time showed 2 mm of induration.  She has a 15-pack-year smoking history.  Temperature is 38.1 C (100.6 F), blood pressure is 110/70 mm Hg, and pulse is 112/min.  Mucous membranes are dry.  Breath sounds are diminished at the right lung base.  Chest CT scan is shown below. Which of the following is the most likely diagnosis? A. Bacterial pneumonia B. Lung cancer C. Pneumocystis pneumonia D. Pulmonary thromboembolism E. Pulmonary tuberculosis

N-acetylcysteine should be started immediately or empirically in following situations: – When a patient presents 8 hours or more after ingestion. – When serum paracetamol level is not available within an 8-hour time window. – When there is uncertainty as to the timing of the overdose. – When the patient is unconscious or has a suspected overdose

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Case-based MCQ | #MCQ_107 •••••••••••••••••••••••••••••••••••••• Correct Answer Is D This patient presents with a rare but life-threatening hypermetabolic state of thyroid storm. It occurs in patients with known or undiagnosed hyperthyroidism and is usually triggered by infection, trauma, myocardial infarction, stroke, or noncompliance with anti-hyperthyroid medications. Thyroid storm is a clinical diagnosis. The signs and symptoms of this disorder reflect an overactive sympathetic system and include fever, tachycardia out of the proportion to the fever, GI symptoms, and altered mental status. Patients may also develop high-output heart failure. The clue to the diagnosis in this case is the patient’s known hyperthyroidism.Pheochromocytoma presents with a similar hyperadrenergic state caused by a catecholamine-secreting tumor but does not result in altered mentation. The hallmark of this disease is hypertension associated with headache, palpitations, and diaphoresis. Cocaine acts as a CNS stimulant by blocking reuptake of excitatory neurotransmitters norepinephrine, dopamine, and serotonin. It is, however, less likely than thyroid storm in this patient given her underlying hyperthyroidism and pulmonary infection. Heat stroke should be suspected in patients with core body temperature > 104°F (> 40°C) and altered mental status. Neuroleptic malignant syndrome is a rare life-threatening reaction to a medication with dopamine receptor antagonism. Such medications include neuroleptics, such as haloperidol, clozapine, and risperidone, lithium and many antiemetics, such as prochlorperazine, promethazine, and metoclopramide. The syndrome presents as fever, altered mental status, and muscular rigidity.  

A 44-year-old agitated woman is brought to the ED by her husband. He states that she has had fevers to 38.8°C, and a productive cough at home for the last 3 days. Today she became labile, agitated, and complained of abdominal pain. She was recently diagnosed with Graves disease and started on PTU. Her BP is 156/87 mm Hg, HR is 145 beats per minute, temperature is 38.1°C, and RR is 20 breaths per minute. On examination, the patient is agitated, confused, and has rales on auscultation bilaterally. Which of the following is the most likely diagnosis? A. Pheochromocytoma B. Cocaine ingestion C. Heat stroke D. Thyroid storm E. Neuroleptic malignant syndrome

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Case-based MCQ | #MCQ_106 •••••••••••••••••••••••••••••••••••••• Correct Answer Is B This clinical picture is suggestive of Noonan syndrome. This is an autosomal dominant disorder with mutation of chromosome 11. It has been described as the male Turner's syndrome, but affects both sexes. Clinical features of the syndrome include the following: Facial/eye features Triangular face Hypertelorism (increased distance between the eyes) Down-slanting eyes Ptosis Strabismus – seen in 48% Amblyopia – seen in 33% Refractive errors – seen in 61% Low-set ears with thickened helices High nasal bridge Short webbed neck Chest/back features Pectus carinatum/excavatum Scoliosis Cardiac features Stenotic/dysplastic pulmonic valve is the characteristic cardiac anomaly Hypertrophic cardiomyopathy (obstructive and non-obstructive) – seen in as many as 30% Virtually all types of congenital heart defects have been described in patients with Noonan syndrome Abdominal features Hepatosplenomegaly unrelated to cardiac disease – seen in 25% of the patients Genitourinary features Renal anomalies are present in 10% of patients but are not clinically significant More than half of male patients have undescended testes Skeletal features Joint laxity is present – seen in more than 50% of the patients Less common findings include talipes equinovarus (club foot) that is an excessively turned-in foot and high medial longitudinal arc, radioulnar synostosis (fusion), cervical spine fusion, and joint contractures. Skin findings Lymphedema Prominent pads of fingers and toes – seen in 67% Follicular keratosis of face and extensor surfaces – seen in 14% Multiple lentigines (a lentigo is a small, sharply circumscribed, pigmented macule surrounded by normal-appearing skin) – seen in 3% Neurological findings Hypotonia Seizure disorders – seen in 13% Unexplained peripheral neuropathy – not seen frequently Mental retardation Previously, patients with Noonan syndrome were thought to have a form of Turner syndrome, as clinical picture is similar to that of Turner’s. Myopia and ectopic ocular lens is consistent with Marfan syndrome and not are features seen in Noonan syndrome

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Case-based MCQ | #MCQ_105 •••••••••••••••••••••••••••••••••••••• A 2-year-old boy is brought to your clinic due to a 3-day history of fever with occasional cough and coryza. On clinical history, viral upper respiratory tract infection is suspected. On physical examination, the patient is noted to have down-slanting of palpebral fissures, eyes that are apart more than usual and low-set ears. The height of the patient is smaller than the standard. Which one of the following is not consistent with this condition? A. Pulmonary valve stenosis. B. Myopia and ectopic ocular lens. C. An autosomal disorder involving mutation in chromosome 11. D. Webbed neck. E. Abnormalities in cardiac conduction and rhythm

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🫀Cardiology Cases | #case87 Correct Answer Is C The ECG shows wide-QRS complex tachycardia (WCT) at a rate of approximately 300 bmp. Most WCTs in children are in fact supraventricular tachycardias (SVT) with aberrancy. Compared to SVT with aberrancy, ventricular tachycardia (VT) is rare in children; however, due to seriousness of the condition, Australian Advanced Paediatric Life Support (APLS) and Royal Children Hospital (RCH) guidelines recommend that WCTs are considered and treated as VT until proven otherwise. This approach is different from recommendations by American Heart Association (AHA) that advise to treat WCTs in a hemodynamically stable children as SVT first by a trial of intravenous adenosine (option B) before making a diagnosis of VT. APLS recommends intravenous amiodarone under close monitoring for treatment of symptomatic VT in children with stable hemodynamics, and synchronized DC cardioversion (option D) in those with hemodynamic instability/ shock if there is pulse and defibrillation in the absence of a pulse. This child is hemodynamically stable; therefore, intravenous amiodarone will be the next best step in management. Vagal maneuvers such as immersion of the face in cold water (option A), application of ice pack to the face or Valsalva maneuvers are initial treatment for patients with narrow-QRS complex tachycardia i.e., SVT. Vagal maneuvers suppress the AV node and might worsen the condition in VT. Intravenous beta blockers such as esmolol (option E) are not generally recommended for treatment of VT or SVT in children

🫀Cardiology Cases | #case87 Correct Answer Is C The ECG shows wide-QRS complex tachycardia (WCT) at a rate of approximately 300 bmp. Most WCTs in children are in fact supraventricular tachycardias (SVT) with aberrancy. Compared to SVT with aberrancy, ventricular tachycardia (VT) is rare in children; however, due to seriousness of the condition, Australian Advanced Paediatric Life Support (APLS) and Royal Children Hospital (RCH) guidelines recommend that WCTs are considered and treated as VT until proven otherwise. This approach is different from recommendations by American Heart Association (AHA) that advise to treat WCTs in a hemodynamically stable children as SVT first by a trial of intravenous adenosine (option B) before making a diagnosis of VT. APLS recommends intravenous amiodarone under close monitoring for treatment of symptomatic VT in children with stable hemodynamics, and synchronized DC cardioversion (option D) in those with hemodynamic instability/ shock if there is pulse and defibrillation in the absence of a pulse. This child is hemodynamically stable; therefore, intravenous amiodarone will be the next best step in management. Vagal maneuvers such as immersion of the face in cold water (option A), application of ice pack to the face or Valsalva maneuvers are initial treatment for patients with narrow-QRS complex tachycardia i.e., SVT. Vagal maneuvers suppress the AV node and might worsen the condition in VT. Intravenous beta blockers such as esmolol (option E) are not generally recommended for treatment of VT or SVT in children