Cardiology Practice Questions

Q: What is the axis in the ECG provided?

Right axis deviation. ***Right axis deviation*** - The **QRS complex** is predominantly **negative in Lead I** and predominantly **positive in Lead aVF**. - This combination indicates that the mean QRS electrical vector lies between **+90° and +180°**, which is characteristic of right axis deviation. *Normal* - A **normal axis** typically shows a predominantly **positive QRS complex** in both Lead I and Lead aVF. - This ECG shows a negative QRS in Lead I, ruling out a normal axis. *Left axis deviation* - **Left axis deviation** is characterized by a predominantly **positive QRS complex** in Lead I and a predominantly **negative QRS complex** in Lead aVF. - This ECG shows the opposite pattern (negative Lead I, positive aVF), ruling out left axis deviation. *Extreme axis deviation* - **Extreme axis deviation**, sometimes called "northwest axis," is present when the **QRS complex** is predominantly **negative in both Lead I and Lead aVF**. - In this ECG, Lead aVF is positive, so extreme axis deviation is not present.

Q: A 50-year-old woman with rheumatic heart disease is on medication for heart disease. She feels unwell for most part of the day. Which of the following medicine is responsible for the ECG changes shown below? (Recent NEET Pattern 2016-17)

Digoxin. ***Digoxin*** - The ECG shows changes characteristic of the **digoxin effect**, specifically **downsloping ST depressions (scooping)** and **flattened or inverted T waves**, particularly in leads with dominant R waves. These findings can occur at therapeutic digoxin concentrations and do not by themselves establish toxicity. - The patient's symptoms of feeling "unwell for most part of the day" are consistent with **digoxin use**, which can include nausea, fatigue, and cardiac arrhythmias. *ACE inhibitor* - ACE inhibitors primarily affect the **renin-angiotensin-aldosterone system** and do not typically cause these specific ECG changes. - Common side effects include cough and **hyperkalemia**, not the "scooped" ST segments seen here. *Diuretics* - Diuretics can cause **electrolyte imbalances**, such as hypokalemia, which might manifest as **flattened T waves** or **prominent U waves** on ECG, but not the characteristic "scooped" ST depression. - The symptoms of malaise are non-specific and while possible with electrolyte disturbances, the specific ECG pattern points away from diuretics as the primary cause. *Ivabradine* - Ivabradine is a **selective If channel inhibitor** that primarily reduces heart rate, without affecting myocardial contractility or repolarization significantly. - It does not cause the **ST segment changes** characteristic of digoxin effect.

Q: A 10-year-old child with Valvular heart disease on heart failure treatment, has the following ECG tracing. What is the diagnosis?

Ventricular bigeminy. ***Ventricular bigeminy*** - The ECG shows a pattern of alternating conducted beats (narrow QRS complexes with preceding P waves) and premature wide QRS complexes, consistent with **ventricular bigeminy**. - The premature wide QRS complexes represent **premature ventricular contractions (PVCs)**, which arise from an ectopic ventricular focus and therefore have a broad, aberrant morphology distinct from the normal sinus beats. - This pattern — every other beat being a PVC — defines ventricular bigeminy and can be seen in the context of **digoxin toxicity**, which is a relevant consideration given this child is on heart failure treatment for valvular heart disease. *Tall tented T-wave* - **Tall, tented T-waves** are characteristic of **hyperkalemia** and are not the predominant feature seen in this tracing. *Non paroxysmal atrial tachycardia with irregular AV block* - The ECG does not demonstrate a sustained atrial tachycardia with variable AV conduction. The alternating wide premature complexes are ventricular in origin, not a reflection of irregular AV nodal block. *Non paroxysmal atrial tachycardia with regular AV block* - The ECG does not show a fixed ratio of P waves to QRS complexes consistent with a regular AV block. The wide premature complexes are PVCs alternating with conducted sinus beats, which is the hallmark of ventricular bigeminy, not atrial tachycardia with AV block.

Q: After thrombolysis for an inferior myocardial infarction, a patient develops intermittent missed beats. A rhythm strip shows progressive prolongation of the PR interval with each successive beat until a P wave is not followed by a QRS complex; the cycle then repeats. What is the most likely diagnosis?

Mobitz I second-degree AV block. Mobitz I second-degree AV block (Wenckebach) is defined by progressive PR-interval prolongation followed by a nonconducted P wave and dropped QRS complex. It usually reflects transient block within the AV node and may occur with an inferior myocardial infarction because the AV node is commonly supplied by the right coronary artery. Mobitz II causes dropped QRS complexes without preceding progressive PR prolongation. Complete heart block produces atrioventricular dissociation, while sick sinus syndrome is caused by sinoatrial node dysfunction rather than this characteristic AV-conduction pattern.

Q: Comment on the diagnosis.

Complete heart block. ***Complete heart block*** - The ECG shows **AV dissociation**, with P waves and QRS complexes occurring independently of each other with no consistent relationship. - Regular dissociated P waves are visible throughout the tracing, and a **slow ventricular escape rhythm** is present, characteristic of complete (third-degree) heart block. - The ventricular escape rate is typically below 40–60 bpm, and the QRS complexes may be wide if the escape focus is ventricular in origin.

Q: A 60-year-old patient is having recurrent syncopal attacks post myocardial infarction. The ECG shows:

Mobitz II heart block. ***Mobitz II heart block*** - The ECG demonstrates consistent **P-P intervals** with some P waves not followed by a QRS complex, indicating **intermittent dropped beats** without progressive PR prolongation. - This type of block is often associated with structural damage to the infranodal conduction system (below the AV node), which is especially concerning in a patient with a recent **myocardial infarction** and recurrent syncope. *Accelerated idioventricular rhythm* - This rhythm is characterized by a **wide QRS complex** at a rate between 60-100 bpm, typically with a gradual onset and termination, and usually does not cause syncope unless rapid or with underlying severe heart disease. - The ECG shows narrow QRS complexes interspersed with dropped beats, not a predominantly wide QRS rhythm originating from the ventricles. *Ventricular bigeminy* - This rhythm involves an alternating pattern of a **normal QRS complex followed by a premature ventricular contraction (PVC)**. - The ECG does not show alternating normal beats and PVCs; rather, it shows P waves without subsequent QRS complexes. *Wenckebach phenomenon* - Also known as Mobitz Type I AV block, it is characterized by **progressive lengthening of the PR interval** until a QRS complex is dropped. - In this ECG, there is no progressive PR interval lengthening; instead, P waves are suddenly blocked, which is characteristic of Mobitz II.

Q: Cannon A waves are seen in the JVP of a patient. ECG shows:

Third degree heart block. ***Third degree heart block*** - **Cannon A waves** in the JVP occur when the right atrium contracts against a closed tricuspid valve, which happens when atrial and ventricular contractions are **dissociated** as seen in **complete heart block**. - In the provided ECG, there is complete dissociation between P waves (atrial activity) and QRS complexes (ventricular activity), with P waves occurring regularly but independently of the QRS complexes, which signifies a **third-degree (complete) heart block**. *First degree heart block* - Characterized by a **prolonged PR interval** (>0.20 seconds) where every P wave is followed by a QRS complex. - There is no dissociation of P waves and QRS complexes, and therefore no cannon A waves due to atrial contraction against a closed tricuspid valve. *Second degree heart block* - Involves some P waves not being followed by a QRS complex, indicating **intermittent conduction failure**. - There can be Wenckebach (Mobitz I) or Mobitz II, both of which involve some degree of P-wave-QRS coupling, usually not leading to constant or prominent cannon A waves. *Mobitz II heart block* - Defined by intermittently **dropped QRS complexes** without progressive PR lengthening, often with a constant PR interval before the drop. - While some dropped beats occur, there is still a clear relationship between the P waves and the conducted QRS complexes, which differs from the continuous and complete AV dissociation seen with cannon A waves in third-degree block.

Q: A 56-year-old woman presents with word-finding difficulty and hand weakness for 1 hour. ECG was done to find cause of TIA. ECG shows:

Atrial flutter. ***Atrial flutter*** - The ECG shows **organized, repetitive flutter waves** (F waves) with a characteristic **sawtooth pattern** most visible in leads II, III, and aVF, which are classic features of atrial flutter. - The ventricular response is relatively regular, reflecting a consistent atrioventricular conduction ratio (e.g., 2:1 or 4:1 block), producing a regular or near-regular ventricular rate. - The **transient ischemic attack (TIA)** symptoms (word-finding difficulty, hand weakness) in this patient are consistent with an embolic event, which can occur in atrial flutter due to thrombus formation in the atria. *Atrial fibrillation* - Atrial fibrillation is characterized by an **irregularly irregular rhythm** with **no discernible P waves** and chaotic atrial activity. The ECG in this case shows organized flutter waves rather than the absent, chaotic atrial activity of atrial fibrillation, ruling out this diagnosis. *Paroxysmal atrial tachycardia* - This rhythm is characterized by a **sudden onset and cessation** of a regular, fast heart rate (typically 150-250 bpm) with a **uniform P wave morphology** that differs from sinus P waves. - The ECG in question shows sawtooth flutter waves rather than the distinct, uniform P waves characteristic of paroxysmal atrial tachycardia. *Multifocal atrial tachycardia* - Multifocal atrial tachycardia (MAT) is characterized by **at least three different P wave morphologies** in the same lead, an **irregularly irregular rhythm**, and varying PR and RR intervals. - The organized, repetitive flutter waves and relatively regular ventricular response seen on this ECG are not consistent with MAT.

Q: Identify the ECG finding shown below:

Atrial flutter with 2:1 AV conduction. ***Atrial flutter with 2:1 AV conduction*** - The ECG shows a **regular narrow-complex tachycardia** at approximately **150 bpm**, which is the classic ventricular rate seen in atrial flutter with 2:1 AV conduction. - The atrial rate in typical atrial flutter is approximately **300 bpm**, with flutter waves (sawtooth pattern) visible in the baseline. With 2:1 conduction, every second flutter wave is conducted to the ventricles, producing a ventricular rate of approximately **150 bpm**. - The regular R-R intervals and the presence of flutter waves at approximately 300 bpm distinguish this from other tachycardias. *Widespread ST segment depression with HR of 150 bpm* - While the ventricular rate is indeed approximately **150 bpm**, the baseline deflections represent **flutter waves** rather than true widespread ST segment depression. - Misidentifying flutter waves as ST depression leads to an incorrect diagnosis and inappropriate management. *Irregularly irregular pulse* - The R-R intervals are **regular and consistent**, not irregular. This ECG does not show the unpredictable variation in R-R intervals characteristic of an irregularly irregular rhythm. - There is no evidence of **atrial fibrillation** here; the rhythm is regular at approximately 150 bpm with organized atrial activity at 300 bpm. *Tall T waves in V3-V5* - There are **no prominent tall T waves** in leads V3-V5; the baseline deflections represent flutter waves rather than tall T waves. - The most significant feature is the **regular tachycardia** at 150 bpm with an underlying atrial rate of approximately 300 bpm consistent with atrial flutter.

Q: A 75-year-old male patient presents to the AIIMS emergency with retrosternal chest pain for 6 hours. The following ECG was done. The catheterization laboratory is immediately available and primary PCI can be achieved within the recommended timeframe. What will be the primary management of the patient?

Primary PCI. ***Primary PCI*** - The ECG shows significant **ST-elevation** in leads V1-V5, indicating an acute **anterolateral ST-elevation myocardial infarction (STEMI)**. - For patients presenting within 12 hours of symptom onset with STEMI, **primary percutaneous coronary intervention (PCI)** is the preferred reperfusion strategy, especially when available within recommended timeframes, as it leads to better outcomes and lower mortality compared to thrombolysis. *Thrombolysis* - While thrombolysis is a reperfusion strategy for STEMI, it is generally considered if PCI cannot be performed within 120 minutes of first medical contact or 90 minutes from diagnosis, or if the patient presents early (within 3 hours) and PCI access is significantly delayed. - Given that the patient is at AIIMS (a major medical center likely with PCI capability) and has good timing for intervention (6 hours), **primary PCI** is superior. *Abciximab* - **Abciximab** is a **glycoprotein IIb/IIIa inhibitor** used as an adjunct to PCI to prevent thrombus formation, not a primary reperfusion therapy itself. - It would be administered in conjunction with PCI, but it is not the primary management strategy. *Low molecular weight heparin* - **Low molecular weight heparin (LMWH)** such as enoxaparin is an **anticoagulant** used in STEMI to prevent clot extension and re-occlusion. - While an essential component of STEMI management, it is part of supportive medical therapy and stabilization, not the primary reperfusion strategy for opening the occluded artery.

Question 1

What is the axis in the ECG provided?

Accepted Answer

Right axis deviation

Answer

Normal

Answer

Left axis deviation

Answer

Extreme axis deviation

Question 2

A 50-year-old woman with rheumatic heart disease is on medication for heart disease. She feels unwell for most part of the day. Which of the following medicine is responsible for the ECG changes shown below? (Recent NEET Pattern 2016-17)

Accepted Answer

Digoxin

Answer

ACE inhibitor

Answer

Diuretics

Answer

Ivabradine

Question 3

A 10-year-old child with Valvular heart disease on heart failure treatment, has the following ECG tracing. What is the diagnosis?

Accepted Answer

Ventricular bigeminy

Answer

Tall tented T-wave

Answer

Non paroxysmal atrial tachycardia with irregular AV block

Answer

Non paroxysmal atrial tachycardia with regular AV block

Question 4

After thrombolysis for an inferior myocardial infarction, a patient develops intermittent missed beats. A rhythm strip shows progressive prolongation of the PR interval with each successive beat until a P wave is not followed by a QRS complex; the cycle then repeats. What is the most likely diagnosis?

Accepted Answer

Mobitz I second-degree AV block

Answer

Mobitz II second-degree AV block

Answer

Complete heart block

Answer

Sick sinus syndrome

Question 5

Comment on the diagnosis.

Accepted Answer

Complete heart block

Answer

Right bundle branch block

Answer

Left bundle branch block

Answer

Accelerated idioventricular rhythm

Question 6

A 60-year-old patient is having recurrent syncopal attacks post myocardial infarction. The ECG shows:

Accepted Answer

Mobitz II heart block

Answer

Accelerated idioventricular rhythm

Answer

Ventricular bigeminy

Answer

Wenckebach phenomenon

Question 7

Cannon A waves are seen in the JVP of a patient. ECG shows:

Accepted Answer

Third degree heart block

Answer

First degree heart block

Answer

Second degree heart block

Answer

Mobitz II heart block

Question 8

A 56-year-old woman presents with word-finding difficulty and hand weakness for 1 hour. ECG was done to find cause of TIA. ECG shows:

Accepted Answer

Atrial flutter

Answer

Atrial fibrillation

Answer

Paroxysmal atrial tachycardia

Answer

Multifocal atrial tachycardia

Question 9

Identify the ECG finding shown below:

Accepted Answer

Atrial flutter with 2:1 AV conduction

Answer

Widespread ST segment depression with HR of 150 bpm

Answer

Irregularly irregular pulse

Answer

Tall T waves in V3-V5

Question 10

A 75-year-old male patient presents to the AIIMS emergency with retrosternal chest pain for 6 hours. The following ECG was done. The catheterization laboratory is immediately available and primary PCI can be achieved within the recommended timeframe. What will be the primary management of the patient?

Accepted Answer

Primary PCI

Answer

Thrombolysis

Answer

Abciximab

Answer

Low molecular weight heparin

Cardiology — MCQs

Cardiology — MCQs

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