Cardiology Practice Questions

Q: A 65-year-old man is brought with complaints of breathlessness and chest pain for 4 hours. ECG was done. Which of the following is incorrect?

Normal sinus rhythm. ***Normal sinus rhythm*** - The ECG clearly shows **ST-segment elevation** in leads V2-V4, indicating an ongoing ST-elevation myocardial infarction (STEMI). - Additionally, there are **premature ventricular contractions (PVCs)** visible, interrupting the underlying rhythm, and the rhythm is not perfectly regular, thus not a normal sinus rhythm. *Normal axis* - The QRS complex in lead I is positive, and in aVF is also positive, indicating a **normal electrical axis** of the heart. - This assessment is based on the general direction of ventricular depolarization in the frontal plane. *ST elevation in V2-V4* - Prominent **ST-segment elevation** is clearly visible in leads V2, V3, and V4, which is indicative of an **acute anterior myocardial infarction**. - This finding is consistent with the patient's symptoms of chest pain and breathlessness. *Premature ventricular contractions* - The ECG shows occasional **wide, bizarre QRS complexes** that are not preceded by a P wave and represent ectopic electrical activity originating in the ventricles. - These are isolated premature beats that interrupt the basic rhythm. *Reciprocal changes in inferior leads* - In anterior wall myocardial infarction, **reciprocal ST-segment depression** is commonly observed in the inferior leads (II, III, aVF). - This represents electrical changes in the opposite wall of the heart and supports the diagnosis of anterior STEMI.

Q: A 65-year-old patient of STEMI underwent thrombolysis with STK. The ECG tracing performed after thrombolysis is shown below. What does it exhibit?

Accelerated idioventricular rhythm. ***Accelerated idioventricular rhythm*** - The ECG shows a wide-QRS rhythm with a regular rate between 50 and 100 bpm, which is characteristic of an **accelerated idioventricular rhythm (AIVR)**. - AIVR is often seen during the **reperfusion phase** after thrombolysis or PCI for STEMI, typically resolves spontaneously, and rarely requires treatment unless it causes hemodynamic instability. *Ventricular bigeminy* - **Ventricular bigeminy** involves a normal sinus beat followed by a premature ventricular contraction (PVC), occurring in an alternating pattern. - The rhythm shown in the ECG is regular and appears to be originating from the ventricles without alternating premature beats and normal beats. *Ventricular tachycardia* - **Ventricular tachycardia (VT)** is a wide-QRS rhythm that typically has a rate greater than 100 bpm (usually 100-250 bpm). - The rate in the provided ECG tracing is slower, falling within the range for AIVR, not VT. *Ventricular escape rhythm* - **Ventricular escape rhythm** is a wide-QRS rhythm with a slower rate, typically between 20 and 40 bpm, serving as a backup pacemaker when higher pacemakers fail. - The rate shown in the ECG is faster (50-100 bpm), which is consistent with AIVR rather than a ventricular escape rhythm. *Wenckebach phenomenon* - The **Wenckebach phenomenon (Mobitz Type I AV block)** is characterized by progressive prolongation of the PR interval until a QRS complex is dropped. - The ECG tracing shows a regular wide-QRS rhythm with no P waves preceding the QRS complexes, which is inconsistent with an AV block.

Q: What ECG finding is shown here?

T-wave alternans. ***T-wave alternans*** - The ECG shows a beat-to-beat alternation of the **T-wave amplitude** or morphology. This is particularly noticeable in lead V3 where consecutive T-waves vary in height. - **T-wave alternans** is a potential marker for **electrical instability of the myocardium** and an increased risk of ventricular arrhythmias and sudden cardiac death. *Hyperacute T-wave* - Hyperacute T-waves are typically seen in the very early stages of a **myocardial infarction** and are usually broad, symmetric, and unusually tall. - While the T-waves in V3 are tall, the key feature here is the **alternating pattern**, not just their height, and they are not particularly broad. *T-wave inversion* - **T-wave inversion** refers to a T-wave that is pointing downwards below the baseline, which is not seen in the provided ECG lead (V3 shows upright T-waves). - Inverted T-waves can indicate myocardial ischemia, infarction, or other cardiac conditions. *Wellens syndrome* - **Wellens syndrome** presents with characteristic **biphasic or deeply inverted T-waves** in the precordial leads (V2-V3), typically indicating critical stenosis of the left anterior descending (LAD) artery. - While Wellens syndrome involves T-wave abnormalities in V3, it shows a consistent pattern of inverted or biphasic T-waves, not the alternating amplitude pattern seen here. *Artifact* - **Artifacts** are disturbances or errors in the ECG tracing caused by external factors such as patient movement, electrical interference, or poor electrode contact. - While the tracing quality looks generally good, the consistent, rhythmic alternation of the T-wave morphology is a physiological phenomenon rather than a random artifact.

Q: What is incorrect about the ECG shown below?

QRS duration is less than 0.08 seconds. ***QRS duration is less than 0.08 seconds*** - The **QRS duration** represents **ventricular depolarization** and is measured from the beginning of the QRS complex to its end. - In this ECG, the QRS duration is roughly 3 small squares, which corresponds to **0.12 seconds** (3 x 0.04 seconds), making the statement "less than 0.08 seconds" incorrect. *PR interval is 0.16 seconds* - The **PR interval** is measured from the beginning of the P wave to the beginning of the QRS complex, representing **atrial and AV nodal conduction**. - On this ECG, the PR interval spans approximately 4 small squares (0.04 seconds/square), which totals to **0.16 seconds**, making this statement correct. *T-wave alternans* - **T-wave alternans** refers to beat-to-beat alternating changes in the **amplitude or morphology of the T wave**, which can indicate **cardiac electrical instability**. - This ECG shows **consistent T-wave morphology** and amplitude across consecutive beats, thus T-wave alternans is not present. *Heart rate is 75 bpm* - To calculate the **heart rate**, divide 300 by the number of large squares between two R waves. There are 4 large squares. - A heart rate of **75 bpm** (300/4) is an accurate assessment for this ECG based on the **R-R interval**. *QRS axis is normal* - The **QRS axis** represents the overall direction of ventricular depolarization in the frontal plane. Normal axis ranges from **-30° to +90°**. - Based on the ECG appearance with positive deflections in leads I and aVF, the axis appears to be within normal limits, making this statement correct.

Q: Comment on the ECG shown:

VT. ***VT*** - The ECG shows a **wide complex tachycardia** with **QRS duration > 0.12 seconds**, which is a hallmark of ventricular tachycardia. - The rhythm is regular with a fast rate, and there is **AV dissociation** visible in several leads (e.g., V1, V2), indicating the ventricles and atria are beating independently. - **AV dissociation is pathognomonic for VT** and is the key distinguishing feature in this ECG. *PSVT* - **Paroxysmal supraventricular tachycardia (PSVT)** typically presents with a **narrow QRS complex** (<0.12 seconds) as it originates above the ventricles. - This ECG clearly shows **wide QRS complexes**, ruling out typical PSVT. *Ventricular fibrillation* - **Ventricular fibrillation (VF)** is characterized by **chaotic, irregular electrical activity** with no distinguishable QRS complexes, P waves, or T waves, leading to cardiac arrest. - The ECG displayed shows a **regular rhythm** with clearly defined, albeit wide, QRS complexes. *Junctional tachycardia* - **Junctional tachycardia** typically presents with a **narrow QRS complex** and an absent or inverted P wave, often occurring before or after the QRS complex. - The wide QRS complexes seen in this ECG are inconsistent with a junctional origin. *SVT with aberrancy* - **SVT with aberrant conduction** (e.g., RBBB or LBBB pattern) can present with wide QRS complexes, making it a differential for wide complex tachycardia. - However, the presence of **AV dissociation** in this ECG strongly favors VT over SVT with aberrancy, as SVT maintains 1:1 AV conduction.

Q: A 45-year-old non-smoker presents with increasing breathlessness. The ECG shows:

Right ventricular hypertrophy. ***Right ventricular hypertrophy*** - The ECG shows a **right axis deviation** (QRS predominantly negative in lead I and positive in aVF) and **tall R waves in V1** with deep S waves in V5/V6, which are classic signs of right ventricular hypertrophy (RVH). - The patient's symptom of increasing **breathlessness** combined with this ECG finding strongly suggests a pulmonary condition contributing to RV strain, such as **pulmonary hypertension** or chronic lung disease, especially given the non-smoker status making COPD less likely, but not ruling out other lung conditions. *Atrial fibrillation* - Atrial fibrillation is characterized by **irregularly irregular R-R intervals** and the **absence of discernible P waves**, neither of which are evident in this ECG. - The rhythm appears regular, and P waves are visible before most QRS complexes. *Left ventricular hypertrophy* - Left ventricular hypertrophy (LVH) typically presents with **tall R waves in V5/V6** or deep S waves in V1/V2, often accompanied by **left axis deviation** or strain patterns. - The ECG in question demonstrates findings more consistent with RVH, including right axis deviation and tall R waves in V1. *Acute coronary syndrome* - Acute coronary syndrome typically shows **ST-segment elevation or depression**, **T wave inversions**, or **pathological Q waves** depending on the type and stage of infarction. - While breathlessness can be a symptom of ACS, the ECG findings here (right axis deviation, tall R in V1) are characteristic of chronic RVH rather than acute ischemic changes. *Normal tracing* - The ECG shows significant abnormalities, including **right axis deviation** and pronounced voltage criteria in precordial leads (tall R in V1), which are not features of a normal ECG. - These findings suggest an underlying cardiac pathology, specifically right ventricular hypertrophy.

Question 1

A hypertensive 50-year-old patient presents with diffuse chest pain at rest for 1 hour. CPK-MB is normal and ECG is given below. Which of the following is correct?

Accepted Answer

Unstable angina

Answer

Coronary artery dissection

Answer

Hibernating myocardium

Answer

Normal tracing

Answer

NSTEMI

Question 2

A 65-year-old man is brought with complaints of breathlessness and chest pain for 4 hours. ECG was done. Which of the following is incorrect?

Accepted Answer

Normal sinus rhythm

Answer

Normal axis

Answer

ST elevation in V2-V4

Answer

Premature ventricular contractions

Answer

Reciprocal changes in inferior leads

Question 3

A 65-year-old patient of STEMI underwent thrombolysis with STK. The ECG tracing performed after thrombolysis is shown below. What does it exhibit?

Accepted Answer

Accelerated idioventricular rhythm

Answer

Ventricular bigeminy

Answer

Ventricular tachycardia

Answer

Wenckebach phenomenon

Answer

Ventricular escape rhythm

Question 4

What ECG finding is shown here?

Accepted Answer

T-wave alternans

Answer

Hyperacute T-wave

Answer

T-wave inversion

Answer

Artifact

Answer

Wellens syndrome

Question 5

What is incorrect about the ECG shown below?

Accepted Answer

QRS duration is less than 0.08 seconds

Answer

PR interval is 0.16 seconds

Answer

T-wave alternans

Answer

Heart rate is 75 bpm

Answer

QRS axis is normal

Question 6

A 50-year-old man is admitted to hospital with Levine sign. BP on admission is 70/50 mm Hg. On auscultation S2 is wide split with S3 gallop rhythm. The ECG is shown below. Which is the correct statement about this patient?

Accepted Answer

Start Streptokinase

Answer

Give bolus fluid

Answer

IV Atropine

Answer

IV Metoprolol

Answer

Start IV Dopamine

Question 7

A 40-year-old man was admitted to the hospital emergency with sudden onset of symptoms and signs of severe left ventricular failure. What would be the best management of this patient?

Accepted Answer

DC shock 25-50 J

Answer

Esmolol

Answer

Ibutilide

Answer

Digoxin

Answer

Adenosine

Question 8

A 50-year-old man is admitted to hospital with Levine sign. BP on admission is 90/60 mm Hg. On auscultation S2 is wide split with S3 gallop rhythm. Which is correct statement about this patient?

Accepted Answer

RCA occlusion with RV dysfunction

Answer

LAD occlusion with LV dysfunction

Answer

Posterior descending artery blockage with RV dysfunction

Answer

Left circumflex artery blockage with LV dysfunction

Answer

Obtuse marginal artery occlusion with lateral wall dysfunction

Question 9

Comment on the ECG shown:

Accepted Answer

VT

Answer

PSVT

Answer

Ventricular fibrillation

Answer

Junctional tachycardia

Answer

SVT with aberrancy

Question 10

A 45-year-old non-smoker presents with increasing breathlessness. The ECG shows:

Accepted Answer

Right ventricular hypertrophy

Answer

Atrial fibrillation

Answer

Left ventricular hypertrophy

Answer

Normal tracing

Answer

Acute coronary syndrome

Cardiology — MCQs

Cardiology — MCQs

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