IBHRE - International Board of Heart Rhythm Examiners Arrhythmia Interpretation and Diagnosis Questions and Answers

Question 1

A 65-year-old male with a history of myocardial infarction presents with a regular, wide complex tachycardia at 150 bpm.
The ECG shows a QRS duration of 160 ms, a northwest axis, and evidence of AV dissociation.
In lead V1, there is a monophasic R wave.
Which of the following is the most likely diagnosis?

Accepted Answer

Ventricular tachycardia

Answer

Supraventricular tachycardia with aberrancy

Answer

Atrial flutter with a bundle branch block

Answer

Antidromic atrioventricular reentrant tachycardia

Question 2

A 58-year-old patient presents to the clinic for a follow-up visit. They mention having intermittent, crushing chest pain over the past week, but are currently pain-free. The ECG shows deeply inverted, symmetric T-waves in leads V2 and V3, with minimal (<1mm) ST-segment elevation and preserved R-wave progression. What is the most likely diagnosis?

Accepted Answer

Wellens' syndrome

Answer

Brugada syndrome

Answer

Acute pericarditis

Answer

Left ventricular hypertrophy with strain

Question 3

Which of the following ECG findings is the defining characteristic of a Mobitz Type II second-degree atrioventricular block?

Accepted Answer

A constant PR interval in all conducted beats before an unexpected, non-conducted P-wave.

Answer

Progressive prolongation of the PR interval until a QRS complex is dropped.

Answer

Complete dissociation between P-waves and QRS complexes.

Answer

A PR interval that is consistently greater than 200 ms.

Question 4

A patient with a dual-chamber pacemaker presents with palpitations. Device interrogation reveals a tachycardia with a ventricular paced rate at the programmed upper tracking rate. The intracardiac electrogram shows a consistent 1:1 ventriculoatrial (VA) conduction pattern where a ventricular paced event is followed by a retrograde atrial sensed event, which then triggers the next ventricular paced event. What is the most likely diagnosis?

Accepted Answer

Pacemaker-mediated tachycardia (PMT)

Answer

Atrial fibrillation with rapid ventricular response

Answer

Sensor-indicated tachycardia

Answer

Runaway pacemaker

Question 5

Which of the following ECG findings is considered the only potentially diagnostic pattern for Brugada syndrome without provocative testing?

Accepted Answer

Coved-type ST-segment elevation of ≥2 mm in at least one right precordial lead (V1-V3) followed by a negative T-wave.

Answer

Saddleback-shaped ST-segment elevation of ≥2 mm in V1-V2.

Answer

Deeply inverted T-waves in leads V2-V3 with preserved R-wave progression.

Answer

ST-segment elevation >1 mm in leads II, III, and aVF.

Question 6

In analyzing a narrow complex tachycardia, which of the following findings would most strongly favor a diagnosis of typical atrioventricular nodal reentrant tachycardia (AVNRT) over orthodromic atrioventricular reentrant tachycardia (AVRT)?

Accepted Answer

A visible retrograde P-wave (pseudo r' in V1 or pseudo S in inferior leads) immediately following the QRS complex, resulting in a short RP interval.

Answer

A long RP interval where the P-wave is clearly visible in the ST segment.

Answer

The presence of QRS alternans.

Answer

Initiation of the tachycardia by a premature ventricular contraction.