Arrhythmias Practice Questions

Q: Match the following A. Atrial fibrillation B. Atrial flutter C. PSVT D. Ventricular tachycardia

A-2, B-1, C-3, D-4. ***A-2, B-1, C-3, D-4*** - Image 2 shows irregularly irregular QRS complexes with no discernible P waves, which is characteristic of **atrial fibrillation**. - Image 1 shows a "sawtooth" pattern of atrial activity, indicative of **atrial flutter**. - Image 3 displays a narrow complex tachycardia with a very regular rhythm, consistent with **PSVT**. - Image 4 demonstrates wide, regular QRS complexes without clear P waves, which is the hallmark of **ventricular tachycardia**. *A-1, B-2, C-3, D-4* - This option incorrectly matches atrial fibrillation with the "sawtooth" pattern (image 1) and atrial flutter with the irregularly irregular rhythm (image 2). - Atrial fibrillation is characterized by the absence of discrete P waves and irregular ventricular response (image 2), while atrial flutter shows organized atrial activity with a "sawtooth" pattern (image 1). *A-1, B-2, C-4, D-3* - This option misidentifies image 1 as atrial fibrillation and image 2 as atrial flutter, which are reversed. - It also incorrectly matches PSVT with image 4 (ventricular tachycardia) and ventricular tachycardia with image 3 (PSVT). *A-2, B-1, C-4, D-3* - This option correctly identifies atrial fibrillation (A-2) and atrial flutter (B-1), but incorrectly swaps the ventricular and supraventricular tachycardias. - Image 3 shows narrow complex tachycardia (PSVT), not the wide complex pattern of ventricular tachycardia seen in image 4. *A-4, B-3, C-2, D-1* - This option incorrectly matches all the rhythms to the wrong images, demonstrating a fundamental misunderstanding of their characteristic ECG features. - For example, it matches atrial fibrillation to image 4 (ventricular tachycardia) and ventricular tachycardia to image 1 (atrial flutter).

Q: A patient is pulseless with the following rhythm shown in the ECG. What is the next best step in management?

Defibrillate and continue chest compression. ***Defibrillate and continue chest compression*** - This scenario describes a **pulseless ventricular tachycardia (pVT)**, which is a **shockable rhythm**. - Immediate defibrillation is crucial, followed by resuming **chest compressions** without delay, as per advanced cardiac life support (ACLS) guidelines. - The correct sequence is: shock → immediate CPR for 2 minutes → rhythm/pulse check. *Defibrillate and check pulse* - While defibrillation is the correct initial intervention for a shockable rhythm, checking the pulse immediately after is incorrect. - Chest compressions should be resumed immediately after a shock for 2 minutes before stopping to check a pulse. - Minimizing interruptions in chest compressions is critical for survival. *Check pulse and give synchronized DC* - Checking a pulse before any intervention wastes critical time in a pulseless patient with a shockable rhythm; immediate defibrillation is indicated. - Synchronized direct current (DC) cardioversion is used for unstable patients **with a pulse** (e.g., unstable ventricular tachycardia with a pulse), not for pulseless rhythms. *Give synchronized DC and continue chest compressions* - Synchronized DC cardioversion is inappropriate for a **pulseless rhythm**; unsynchronized defibrillation is required. - Synchronization requires an R wave to time the shock, which is not feasible in pulseless VT management. *Start chest compressions and give epinephrine* - While chest compressions are essential, the **immediate priority** for a shockable rhythm (pVT/VF) is **defibrillation**. - Epinephrine is given during CPR cycles (after the first shock), but defibrillation must come first for shockable rhythms. - This would be the approach for **non-shockable rhythms** (PEA/asystole), not pulseless VT.

Q: Match the following ECG findings (1-4) with their corresponding arrhythmias (A-D): 1. Sawtooth pattern in leads II, III, aVF with regular ventricular response 2. Irregularly irregular rhythm with absent P waves 3. Narrow QRS tachycardia with abrupt onset/termination 4. Wide QRS tachycardia with AV dissociation A. Atrial fibrillation B. PSVT (Paroxysmal Supraventricular Tachycardia) C. Atrial flutter D. Ventricular tachycardia What is the correct matching?

A-2, B-3, C-1, D-4. The correct matching is **A-2, B-3, C-1, D-4**: ***C-1: Atrial flutter - Sawtooth pattern*** - Atrial flutter is characterized by a **sawtooth pattern** of flutter waves, particularly prominent in leads II, III, and aVF - Represents rapid, organized atrial depolarization at 250-350 bpm - Regular ventricular response due to **AV block** (commonly 2:1 or 4:1) - The sawtooth pattern is the pathognomonic feature ***A-2: Atrial fibrillation - Irregularly irregular rhythm*** - Identified by an **irregularly irregular rhythm** with absent distinct P waves - Replaced by chaotic fibrillatory waves showing disorganized atrial activity - Ventricular rate is rapid and unpredictable - No organized atrial pattern unlike the regular flutter waves ***B-3: PSVT - Narrow QRS with abrupt onset/termination*** - Presents with **narrow QRS complex tachycardia** (QRS 0.12 seconds) - **AV dissociation** is a key diagnostic feature showing independent atrial and ventricular activity - Originates from ventricular tissue, not supraventricular structures - Lacks the organized P wave patterns seen in atrial arrhythmias

Q: A 45-year-old male is brought into the emergency department by emergency medical services. The patient has a history of substance abuse and was found down in his apartment lying on his right arm. He was last seen 24 hours earlier by his mother who lives in the same building. He is disoriented and unable to answer any questions. His vitals are HR 48, T 97.6, RR 18, BP 100/75. You decide to obtain an EKG as shown in Figure 1. Which of the following is most likely the cause of this patient's EKG results?

Hyperkalemia. ***Hyperkalemia*** - This patient's presentation with **bradycardia**, potential **rhabdomyolysis** from being "found down" and immobility, and the EKG showing changes like **peaked T waves** (often the first EKG sign) are all highly suggestive of hyperkalemia. - Prolonged immobility (lying on arm for 24 hours) can lead to **muscle breakdown**, releasing significant intracellular potassium into the bloodstream. *Hypocalcemia* - Hypocalcemia typically manifests on EKG as **QT interval prolongation**, not peaked T waves or bradycardia. - While some forms of muscle injury can affect calcium, it's not the primary EKG finding expected with rhabdomyolysis. *Hypercalcemia* - Hypercalcemia is associated with a **shortened QT interval** on EKG. - It is unlikely to cause severe bradycardia or marked T wave changes as seen in profound hyperkalemia. *Hypomagnesemia* - Hypomagnesemia can cause various EKG changes, including **QT prolongation** and an increased risk of **torsades de pointes**, but not typically the peaked T waves characteristic of this scenario. - It often coexists with hypokalemia but isn't the primary explanation for the EKG findings described. *Hypokalemia* - Hypokalemia is associated with **flattened T waves**, prominent **U waves**, and often **QT prolongation** as well as various arrhythmias. - It is highly unlikely to cause the **peaked T waves** and **bradycardia** observed in this patient.

Question 1

Match the following
A. Atrial fibrillation
B. Atrial flutter
C. PSVT
D. Ventricular tachycardia

Accepted Answer

A-2, B-1, C-3, D-4

Answer

A-1, B-2, C-3, D-4

Answer

A-1, B-2, C-4, D-3

Answer

A-4, B-3, C-2, D-1

Answer

A-2, B-1, C-4, D-3

Question 2

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?

Accepted Answer

IV Digoxin for control rate

Answer

Start on anticoagulants

Answer

Start β-blocker

Answer

Cardioversion to correct rhythm if hemodynamically remains unstable even after medical management

Answer

Administer diuretics for fluid overload

Question 3

A patient is pulseless with the following rhythm shown in the ECG. What is the next best step in management?

Accepted Answer

Defibrillate and continue chest compression

Answer

Defibrillate and check pulse

Answer

Check pulse and give synchronized DC

Answer

Give synchronized DC and continue chest compressions

Answer

Start chest compressions and give epinephrine

Question 4

Match the following ECG findings (1-4) with their corresponding arrhythmias (A-D):

1. Sawtooth pattern in leads II, III, aVF with regular ventricular response
2. Irregularly irregular rhythm with absent P waves
3. Narrow QRS tachycardia with abrupt onset/termination
4. Wide QRS tachycardia with AV dissociation

A. Atrial fibrillation
B. PSVT (Paroxysmal Supraventricular Tachycardia)
C. Atrial flutter
D. Ventricular tachycardia

What is the correct matching?

Accepted Answer

A-2, B-3, C-1, D-4

Answer

A-2, B-1, C-3, D-4

Answer

A-1, B-2, C-4, D-3

Answer

A-4, B-3, C-2, D-1

Answer

A-1, B-2, C-3, D-4

Question 5

A 45-year-old male is brought into the emergency department by emergency medical services. The patient has a history of substance abuse and was found down in his apartment lying on his right arm. He was last seen 24 hours earlier by his mother who lives in the same building. He is disoriented and unable to answer any questions. His vitals are HR 48, T 97.6, RR 18, BP 100/75. You decide to obtain an EKG as shown in Figure 1. Which of the following is most likely the cause of this patient's EKG results?

Accepted Answer

Hyperkalemia

Answer

Hypocalcemia

Answer

Hypercalcemia

Answer

Hypomagnesemia

Answer

Hypokalemia

Arrhythmias — MCQs

Arrhythmias — MCQs

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