Arrhythmias — MCQs

A patient with a history of hypertension presents with atrial fibrillation, shortness of breath, and bilateral basal crackles on auscultation. Which of the following would be the least important in the management of this patient?

A 52-year-old woman presents with decreased exercise tolerance and difficulty breathing on exertion and while sleeping at night. She says that she requires 2 pillows to sleep at night to alleviate her shortness of breath. These symptoms started 6 months ago and are gradually increasing in severity. She does not have any chronic health problems. She has smoked 15 cigarettes per day for the past 20 years and drinks alcohol occasionally. Vital signs include: blood pressure 110/70 mm Hg, temperature 36.7°C (98.0°F), and regular pulse 90/min. On physical examination, the first heart sound is loud, and there is a low pitched rumbling murmur best heard at the cardiac apex. This patient is at high risk of developing which of the following complications?

A 63-year-old woman is brought to the emergency department 1 hour after the onset of right-sided weakness. She was eating breakfast when suddenly she could not lift her spoon. She cried out to her husband but her speech was slurred. For the past 4 months, she has been more anxious than usual and felt fatigued. She used to exercise regularly but had to give up her exercise routine 3 months ago because of lightheadedness and shortness of breath with exertion. She has a history of hypertension. She is a tax accountant and has had increased stress at work recently. She takes lisinopril daily and alprazolam as needed. Her temperature is 37.2°C (99.0°F), pulse is 138/min, respirations are 14/min, and blood pressure is 146/86 mm Hg. Her lungs are clear to auscultation bilaterally and she has an S1 with variable intensity. On neurologic examination, she has a right facial droop and 2/5 strength in the right shoulder, elbow, wrist, and fingers. Sensation is diminished in the right face and arm. Further evaluation is most likely to show which of the following?

A 30-year-old man presents with progressive muscle weakness for the past 6 hours. He says he had significant bilateral ankle pain which onset shortly after completing a triathlon earlier in the day. Then, he says he awoke this morning with bilateral upper and lower extremity weakness, which has progressively worsened. He has no significant past medical history and takes no current medication. The vital signs include: temperature 37.0℃ (98.6℉), pulse 66/min, respiratory rate 21/min, and blood pressure 132/83 mm Hg. On physical examination, the patient has diffuse moderate to severe muscle pain on palpation. His strength is 5 out of 5, and deep tendon reflexes are 2+ in the upper and lower extremities bilaterally. Laboratory findings are significant for the following: Laboratory test Sodium 141 mEq/L Potassium 6.3 mEq/L Chloride 103 mEq/L Bicarbonate 25 mEq/L Blood urea nitrogen (BUN) 31 mg/dL Creatinine 6.1 mg/dL BUN/Creatinine 5.0 Glucose (fasting) 80 mg/dL Calcium 6.3 mg/dL Serum creatine kinase (CK) 90 mcg/L (ref: 10–120 mcg/L) Which of the following is the next best step in the management of this patient?

A 40-year-old man is brought to the emergency department 20 minutes after his wife found him unconscious on the bathroom floor. On arrival, he is conscious and alert. He remembers having palpitations and feeling lightheaded and short of breath before losing consciousness. He takes captopril for hypertension and glyburide for type 2 diabetes mellitus. His vitals are within normal limits. Physical examination shows no abnormalities. Random serum glucose concentration is 85 mg/dL. An ECG shows a short PR interval and a wide QRS complex with initial slurring. Transthoracic echocardiography reveals normal echocardiographic findings with normal left ventricular systolic function. Which of the following is the most likely underlying cause of this patient's findings?

A 23-year-old man comes to the physician because of a 1-year history of episodic shortness of breath. Physical examination shows no abnormalities. Laboratory studies show elevated serum IgE levels. Microscopic examination of the sputum shows eosinophilic, hexagonal, double-pointed crystals. A methacholine challenge test is positive. Exposure to which of the following is most likely responsible for this patient's condition?

A 55-year-old woman presents to the physician with repeated episodes of dizziness for the last 3 months, which are triggered by rising from a supine position and by lying down. The episodes are sudden and usually last for less than 30 seconds. During the episode, she feels as if she is suddenly thrown into a rolling spin. She has no symptoms in the period between episodes. The patient denies having headaches, vomiting, deafness, ear discharge or ear pain. There is no history of a known medical disorder or prolonged consumption of a specific drug. The vital signs are within normal limits. On physical examination, when the physician asks the woman to turn her head 45° to the right, and then to rapidly move from the sitting to the supine position, self-limited rotatory nystagmus is observed following her return to the sitting position. The rest of the neurological examination is normal. Which of the following is the treatment of choice for the condition of this patient?

A 21-year-old woman presents with palpitations and anxiety. She had a recent outpatient ECG that was suggestive of supraventricular tachycardia, but her previous physician failed to find any underlying disease. No other significant past medical history. Her vital signs include blood pressure 102/65 mm Hg, pulse 120/min, respiratory rate 17/min, and temperature 36.5℃ (97.7℉). Electrophysiological studies reveal an atrioventricular nodal reentrant tachycardia. The patient refuses an ablation procedure so it is decided to perform synchronized cardioversion with consequent ongoing management with verapamil. Which of the following ECG features should be monitored in this patient during treatment?

A previously healthy 66-year-old woman comes to the physician because of a 3-day history of fever, cough, and right-sided chest pain. Her temperature is 38.8°C (101.8°F) and respirations are 24/min. Physical examination shows dullness to percussion, increased tactile fremitus, and egophony in the right lower lung field. The remainder of the examination shows no abnormalities. Which of the following is the most likely cause of these findings?

A 55-year-old woman visits the clinic after experiencing what she describes as an odd episode of tingling in her fingers and the sensation of smelling sour milk. She denies loss of consciousness, confusion, or incontinence. She also denies a history of head trauma or the ingestion of toxic substances. Past medical history is significant for type 2 diabetes mellitus, which is well controlled with metformin. Her temperature is 36.8°C (98.2°F), the heart rate is 98/min, the respiratory rate is 15/min, the blood pressure is 100/75 mm Hg, and the O2 saturation is 100% on room air. The physical exam, including a full neurologic and cardiac assessment, demonstrates no abnormal findings. Laboratory findings are shown. Brain MRI does not indicate any areas of infarction or hemorrhage. ECG is normal, and EEG is pending. BUN 15 mg/dL pCO2 40 mmHg Creatinine 0.8 mg/dL Glucose 95 mg/dL Serum chloride 103 mmol/L Serum potassium 3.9 mEq/L Serum sodium 140 mEq/L Total calcium 2.3 mmol/L Magnesium 1.7 mEq/L Phosphate 0.9 mmol/L Hemoglobin 14 g/dL Glycosylated hemoglobin 5.5% Total cholesterol 4 mmol/L Bicarbonate (HCO3) 19 mmol/L Urine toxicology screen is negative. What kind of seizure is most likely being described?