Cardioversion and defibrillation — MCQs

A 55-year-old man presents to his physician with a complaint of recurrent episodes of palpitations over the past 2 weeks. He also mentions that he tends to tire easily. He denies chest pain, breathlessness, dizziness, or syncope, but has a history of ischemic heart disease. He smokes 1 pack of cigarettes every day and drinks alcohol occasionally. The physical examination revealed a temperature of 36.9°C (98.4°F), a pulse of 124/min (irregular), a blood pressure of 142/86 mm Hg, and a respiratory rate of 16/min. Auscultation of his chest is normal with an absence of rales overall lung fields. An ECG was significant for fibrillatory waves and an irregular RR interval. Thus, the physician concludes that the symptoms are due to atrial fibrillation. The patient is prescribed oral diltiazem. Which of the following side effects should the physician warn the patient about?

A 22-year-old woman presents to the emergency department feeling lightheaded and states that her heart is racing. She does not have a history of any chronic medical conditions. She is a college sophomore and plays club volleyball. Although she feels stressed about her upcoming final exams next week, she limits her caffeine intake to 3 cups of coffee per day to get a good night sleep. She notes that her brother takes medication for some type of heart condition, but she does not know the name of it. Both her parents are alive and well. She denies recent illness, injuries, or use of cigarettes, alcohol, or recreational drugs. The pertinent negatives from the review of systems include an absence of fever, nausea, vomiting, sweating, fatigue, or change in bowel habits. The vital signs include: temperature 36.8°C (98.2°F), heart rate 125/min, respiratory rate 15/min, blood pressure 90/75 mm Hg, and oxygen saturation of 100% on room air. The laboratory results are within normal limits. The ECG is significant for a shortened PR interval and widened QRS. Which of the following medications should the patient avoid in this scenario?

Two days after admission for myocardial infarction and subsequent coronary angioplasty, a 65-year-old man becomes distressed and diaphoretic in the cardiac intensive care unit. Suddenly he is no longer responsive. Pulse oximetry does not show a tracing. He has a history of hypertension and depression. Prior to his admission, his medication included ramipril and aripiprazole. Examination shows no carotid pulse. An ECG is shown. After beginning chest compressions, which of the following is the most appropriate step in management of the patient?

One hour after being admitted to the hospital for sharp, acute chest pain and diaphoresis, a 55-year-old woman with type 2 diabetes mellitus loses consciousness in the emergency department. There are no palpable pulses. Chest compressions are started. The patient has a history of breast cancer that was surgically treated 4 years ago. Prior to admission, the patient was on a long bus ride to visit her sister. Her medications include tamoxifen, atorvastatin, metoprolol, metformin, and insulin. Serum troponin levels are elevated. The cardiac rhythm is shown. Which of the following is the most appropriate next step in management?

Two days after coronary artery stent placement for a posterior myocardial infarction, a 70-year-old woman complains of difficulty breathing and retrosternal chest pain. She has a history of atrial fibrillation, for which she takes verapamil. Following stent placement, the patient was started on aspirin and clopidogrel. She appears to be in acute distress and is disoriented. Respirations are 22/min. Pulse oximetry on room air shows an oxygen saturation of 80%. Diffuse crackles are heard on auscultation of the chest. The patient is intubated and mechanical ventilation is started. Shortly afterwards, she becomes unresponsive. Heart sounds are inaudible and her carotid pulses are not palpable. The cardiac monitor shows normal sinus rhythm with T-wave inversion. Which of the following is the most appropriate next step in management?

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?