Arrhythmias Practice Questions

Question 1

A 44-year-old man comes to the emergency department because of persistent palpitations for the past 2 hours. The day before, he was at a wedding, where he drank several glasses of wine and 9–10 vodka cocktails. He has never had similar symptoms before. He is a manager at a software company and has recently had a lot of work-related stress. He is otherwise healthy and takes no medications. His temperature is 36.5°C (97.7°F), pulse is 90/min and irregularly irregular, respirations are 13/min, and his blood pressure is 128/60 mm Hg. Physical examination shows no other abnormalities. An ECG is performed; no P-waves can be identified. Echocardiography shows no valvular abnormalities and normal ventricular function. One hour later, a repeat ECG shows normal P waves followed by narrow QRS complexes. He is still experiencing occasional palpitations. Which of the following is the most appropriate next step in management?

Accepted Answer

Observation

Answer

Electrical cardioversion

Answer

Defibrillation

Answer

Adenosine injection

Answer

Catheter ablation

Question 2

A 75-year-old man presents to the emergency department after an episode of syncope while walking outside with his wife. His wife states that he suddenly appeared pale and collapsed to the ground. She says he remained unconscious for 1 minute. He says he noticed a fluttering in his chest and excessive sweating before the episode. He has type 2 diabetes mellitus, essential hypertension, and chronic stable angina. He has not started any new medications in the past few months. Vital signs reveal: temperature 37.0°C (98.6°F), blood pressure 135/72 mm Hg, and pulse 72/min. Physical examination is unremarkable. ECG shows an old bifascicular block. Echocardiogram and 24-hour Holter monitoring are normal. Which of the following is the best next step in the evaluation of this patient's condition?

Accepted Answer

Continuous loop recorder

Answer

Cardiac enzymes

Answer

Valsalva maneuver

Answer

Electroencephalography (EEG)

Answer

Tilt-table test

Question 3

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?

Accepted Answer

Defibrillation

Answer

Intravenous procainamide

Answer

Cardiac catheterization

Answer

Intravenous amiodarone

Answer

Intravenous magnesium sulfate

Question 4

A 29-year-old woman with Wolff-Parkinson-White syndrome presents to her cardiologist’s office for a follow-up visit. She collapsed at her job and made a trip to the emergency department 1 week ago. At that time, she received a diagnosis of atrial fibrillation with rapid ventricular response and hemodynamic instability. While in the emergency department, she underwent direct-current cardioversion to return her heart to sinus rhythm. Her current medications include procainamide. At the cardiologist’s office, her heart rate is 61/min, respiratory rate is 16/min, the temperature is 36.5°C (97.7°F), and blood pressure is 118/60 mm Hg. Her cardiac examination reveals a regular rhythm and a I/VI systolic ejection murmur best heard at the right upper sternal border. An ECG obtained in the clinic is shown. Which of the following is the most appropriate treatment to prevent further episodes of tachyarrhythmia?

Accepted Answer

Refer her for electrophysiology (EP) study and ablation

Answer

Begin anticoagulation with dabigatran

Answer

Add verapamil to her medication regimen

Answer

Begin anticoagulation with warfarin

Answer

Refer her for right heart catheterization

Question 5

A 26-year-old healthy woman presents with lightheadedness, palpitations, and sweating, which started suddenly after she was frightened by her neighbor’s dog. The patient’s blood pressure is 135/80 mm Hg, the heart rate is 150/min, the respiratory rate is 15/min, and the temperature is 36.6℃ (97.9℉). Her ECG is shown in the exhibit. What is the preferred agent for pharmacologic management of this condition?

Accepted Answer

Adenosine

Answer

Metoprolol

Answer

Amiodarone

Answer

Propafenone

Answer

Verapamil

Question 6

In a patient with acute myocardial ischemia, which of the following cardiovascular structures is at greatest risk of damage?

Accepted Answer

Cardiac conduction system

Answer

Pulmonary valve

Answer

Coronary artery

Answer

Cardiac septum

Answer

Temporal artery

Question 7

A 45-year-old man comes to the physician for a routine health maintenance examination. He feels well. He underwent appendectomy at the age of 25 years. He has a history of hypercholesterolemia that is well controlled with atorvastatin. He is an avid marathon runner and runs 8 miles per day four times a week. His father died of myocardial infarction at the age of 42 years. The patient does not smoke or drink alcohol. His vital signs are within normal limits. Cardiopulmonary examination shows no abnormalities. His abdomen is soft and nontender with a surgical scar in the right lower quadrant. Laboratory studies are within normal limits. An ECG is shown. Which of the following is the most likely diagnosis?

Accepted Answer

Mobitz type I AV block

Answer

Mobitz type II AV block

Answer

First-degree AV block

Answer

Third-degree AV block

Answer

Atrial fibrillation

Question 8

A 40-year-old woman comes to the physician for a 6-month history of recurrent episodes of chest pain, racing pulse, dizziness, and difficulty breathing. The episodes last up to several minutes. She also reports urinary urgency and two episodes of loss of consciousness followed by spontaneous recovery. There is no personal or family history of serious illness. She does not smoke or drink alcohol. Vitals signs are within normal limits. Cardiopulmonary examination shows no abnormalities. Holter monitoring is performed. ECG recordings during episodes of tachycardia show a QRS duration of 100 ms, regular RR-interval, and absent P waves. Which of the following is the most likely underlying cause of this patient's condition?

Accepted Answer

AV node with slow and fast pathway

Answer

Pre-excitation of the ventricles

Answer

Mutations in genes that code for myocyte ion channels

Answer

Macroreentrant rhythm in the right atria through cavotricuspid isthmus

Answer

Fibrosis of the sinoatrial node and surrounding myocardium

Question 9

A 58-year-old man is diagnosed with right lower lobe pneumonia and has been admitted to a tertiary care hospital. His laboratory investigations suggest that he acquired an infection from the hospital where he underwent an elective abdominal surgery 3 weeks ago. His past medical records reveal a history of deep vein thrombosis and pulmonary embolism one year prior. After a steady clinical improvement over 5 days of inpatient treatment, he develops a cough, breathlessness, and hemoptysis on the 6th day. His temperature is 38.6°C (101.5°F), the pulse is 112/min, the blood pressure is 130/84 mm Hg, and the respiratory rate is 28/min. A general examination shows the presence of edema over the right leg and tenderness over the right calf region. Auscultation of the chest reveals localized crackles over the left mammary region and right infrascapular region. However, his heart sounds are normal, except for the presence of tachycardia, and there are no murmurs. Which of the following is the investigation of choice as the immediate next step in this patient’s management?

Accepted Answer

Contrast-enhanced computed tomography (CECT) of chest

Answer

Ventilation-perfusion scanning

Answer

Echocardiography

Answer

Serum brain natriuretic peptide

Answer

Plasma D-dimer

Question 10

A 74-year-old man presents to the emergency department with shortness of breath that started about 30 minutes ago. He is also experiencing chest pain on deep inspiration. He has several significant medical conditions including chronic obstructive pulmonary disease, hypertension, and dyslipidemia. He used to smoke about 3 packs of cigarettes every day until last year when he quit. He was in the emergency room 2 weeks ago for a hemorrhagic stroke which was promptly treated. He currently weighs 97.5 kg (215 lb). His respirations are 20/min, the blood pressure is 110/80 mm Hg, and the pulse is 105/min. On physical examination, Homan's sign is positive. An ECG and chest X-ray are performed. His current oxygen saturation is at 87% and D-dimer results are positive. He is wheeled in for a CT scan. What is the most appropriate initial treatment for this patient?

Accepted Answer

Greenfield filter

Answer

Subcutaneous fondaparinux

Answer

Surgical thrombectomy

Answer

Unfractionated heparin

Answer

Warfarin

Arrhythmias

Study Resources

Lessons

Questions

Flashcards

Lessons

Basic electrophysiology

ECG interpretation fundamentals

Supraventricular tachycardias

Atrial fibrillation and flutter

Ventricular arrhythmias

Bradyarrhythmias and conduction disorders

Sudden cardiac death

Antiarrhythmic medications

Cardioversion and defibrillation

Pacemakers and ICDs

Catheter ablation procedures

Secondary arrhythmias (electrolyte, drug-induced)

Inherited arrhythmia syndromes

Practice Questions

Flashcards

About Arrhythmias for USMLE

Lessons in Arrhythmias

Master Arrhythmias