Cardiology Practice Questions

Q: Which of the following conditions can lead to an abnormal increase in the amplitude of the 'U' wave on an ECG?

Hypokalemia. ***Hypokalemia*** - **Hypokalemia** is a common cause of prominent U waves due to delayed repolarization of **Purkinje fibers**. [1] - Other ECG changes in hypokalemia include **T-wave flattening or inversion** and prolongation of the **QT interval**. [1] *Amiodarone* - **Amiodarone** is an antiarrhythmic drug that primarily prolongs the **QT interval** due to its effect on potassium channels. - While it can affect repolarization, it does not typically cause a prominent U wave; instead, it may cause **bradycardia** and **Torsades de Pointes**. [2] *Quinidine* - **Quinidine** is a Class IA antiarrhythmic drug that prolongs the **QT interval** by blocking potassium channels. [2] - It is known for causing **QT prolongation** and increasing the risk of **Torsades de Pointes**, but not prominently increased U waves. [2] *None of the options* - This option is incorrect as **hypokalemia** is a well-established cause of abnormal U waves on an ECG.

Q: A 28-year-old female presents with progressive dyspnea on exertion and palpitations for the past 6 months. She has a history of recurrent sore throat episodes during childhood. On examination, she has an irregularly irregular pulse, and auscultation reveals a mid-diastolic rumbling murmur at the apex with presystolic accentuation. ECG shows atrial fibrillation with controlled ventricular rate and left atrial enlargement. Echocardiogram demonstrates mitral valve stenosis with commissural fusion, leaflet thickening, and a mitral valve area of 1.2 cm². What is the most likely diagnosis?

Rheumatic mitral stenosis. **Rheumatic mitral stenosis** - The clinical presentation (progressive **dyspnea** on exertion, **palpitations**, history of recurrent sore throat, **irregularly irregular pulse**) and auscultation findings (**mid-diastolic rumbling murmur** at the apex with presystolic accentuation) are classic for **mitral stenosis**. - The echocardiogram findings of **mitral valve stenosis with commissural fusion**, leaflet thickening, and a reduced mitral valve area (1.2 cm²) are pathognomonic for **rheumatic heart disease**, which is a long-term complication of untreated streptococcal pharyngitis (sore throat). *Neovascularization of the valve leaflets* - This is not a primary cause of mitral stenosis and is more typically seen in conditions like infectious endocarditis, though it is not a direct diagnostic feature. - While neovascularization can occur in chronically diseased valves, it doesn't explain the specific valve morphology and clinical course described. *Vegetations on the mitral valve* - **Vegetations** are characteristic of **infective endocarditis** and would typically present with fever, new or changing murmurs, and signs of systemic embolization, none of which are mentioned here. - Although infective endocarditis can cause valve dysfunction, it doesn't typically result in the characteristic **commissural fusion** and leaflet thickening seen in rheumatic disease. *Myxomatous degeneration of the mitral valve* - This condition is the underlying pathology of **mitral valve prolapse** and typically leads to **mitral regurgitation**, not stenosis. - The echocardiographic features would show thickened, redundant leaflets that prolapse into the left atrium during systole, which contradicts the described **mitral stenosis** with **commissural fusion**.

Q: Recommended interventions to reduce the incidence of coronary artery disease include the following except which of the following?

Fat intake < 20% of total energy.. ***Fat intake < 20% of total energy.*** - While reducing unhealthy fat intake is crucial for cardiovascular health, recommending total fat intake to be less than 20% of total energy is generally **too restrictive** and not a standard recommendation for the general population. - Current guidelines focus on the *type* of fat (limiting saturated and trans fats) rather than a strict overall percentage, as healthy fats are essential for various bodily functions [3]. *Dietary cholesterol < 100 mg/1000kcal/d* - Reducing dietary cholesterol intake is a widely accepted recommendation to lower the risk of **coronary artery disease (CAD)**, as high cholesterol contributes to atherosclerosis [3]. - Limiting cholesterol intake to less than 100 mg per 1000 kcal per day aligns with strategies for managing blood lipid levels [1]. *Reduce salt intake to < 5g per day.* - Reducing salt intake to less than 5 grams per day is strongly recommended to lower **blood pressure**, a major risk factor for CAD [2]. - High sodium intake contributes to hypertension, which places increased strain on the cardiovascular system [2]. *No alcohol consumption.* - While excessive alcohol consumption is detrimental to cardiovascular health, a recommendation of **no alcohol consumption** is not universally made to reduce CAD risk. - Moderate alcohol intake (e.g., one drink per day for women, two for men) has been associated with a potential reduction in CAD risk in some studies, though this is debated.

Q: Asynchronous cardioversion is given in:

Ventricular fibrillation. ***Ventricular fibrillation*** - **Asynchronous cardioversion** is also known as **defibrillation**, which means it delivers a shock randomly without synchronization to the cardiac cycle [1]. - **Ventricular fibrillation (VF)** is a chaotic rhythm with no discernible QRS complexes, thus synchronization is impossible and immediate defibrillation is life-saving [1], [2]. *AF* - **Atrial fibrillation (AF)** can be treated with **synchronized cardioversion** if it is unstable or persistent and requires rhythm control, as there are still discernible QRS complexes [3]. - Asynchronous cardioversion is generally not recommended for AF due to the risk of inducing **ventricular fibrillation** if the shock falls on the T-wave [2]. *Atrial flutter* - **Atrial flutter** with a rapid ventricular response is typically treated with **synchronized cardioversion** because the organized atrial activity allows for synchronization of the shock with the QRS complex [3]. - This minimizes the risk of delivering a shock during the vulnerable period of the T-wave, which could lead to more dangerous arrhythmias [2]. *Ventricular tachycardia* - **Ventricular tachycardia (VT)**, if stable and with a pulse, is treated with **synchronized cardioversion** to avoid delivering the shock during the vulnerable T-wave [2]. - If **pulseless VT**, it is treated as **ventricular fibrillation** (asynchronous defibrillation) due to the hemodynamic instability and immediate life threat [1].

Q: A female patient develops chest pain that is not associated with exercise, and chest auscultation shows multiple non-ejection clicks. The investigation used to diagnose the disease is:

Echocardiography for mitral valve prolapse. ***Echocardiography for mitral valve prolapse*** - **Non-ejection clicks** on auscultation are the classic physical finding for **mitral valve prolapse (MVP)**, often accompanied by a **mid-systolic click** and a late systolic murmur. - **Echocardiography** is the definitive diagnostic tool for MVP, allowing visualization of the mitral valve leaflets prolapsing into the left atrium during systole. *Pyrophosphate scan for cardiac amyloidosis* - A **pyrophosphate scan** is used to diagnose **transthyretin cardiac amyloidosis (ATTR-CM)**, which typically presents with heart failure symptoms and restrictive cardiomyopathy. - Cardiac amyloidosis does not typically manifest with isolated non-ejection clicks as its primary auscultatory finding. *ECG for heart rhythm evaluation* - An **ECG** evaluates the electrical activity of the heart for **arrhythmias** or evidence of ischemia or structural changes, such as hypertrophy. - While MVP can be associated with arrhythmias, an ECG alone cannot diagnose the structural abnormality of mitral valve prolapse or explain non-ejection clicks. *Thallium 201 scan for myocardial perfusion* - A **Thallium 201 scan** is a nuclear imaging test used to assess **myocardial perfusion** and detect areas of ischemia or infarction. - It is utilized for evaluating coronary artery disease and does not directly diagnose valvular abnormalities like mitral valve prolapse.

Q: In a patient with congenital prolonged QT syndrome presenting with intermittent torsades de pointes, which of the following is the first-line acute treatment?

Magnesium sulfate. ### Magnesium sulfate - **Magnesium sulfate** is the **first-line acute treatment** for **torsades de pointes (TdP)**, regardless of serum magnesium levels. - It helps stabilize the cardiac membrane, reducing ectopic activity and inhibiting triggered activity responsible for TdP. ### Beta-blockers - **Beta-blockers** are primarily used for **long-term management** of congenital **long QT syndrome** to prevent future episodes of TdP by reducing sympathetic tone and heart rate [2]. - They are **not** the immediate acute treatment for an ongoing TdP episode [2]. ### Isoprenaline for heart rate support - While sometimes used in specific forms of congenital LQTS, **isoprenaline** (or other beta-agonists) is generally **contraindicated** in TdP as it can worsen the arrhythmia by increasing heart rate and prolonging the QT interval [1]. - It might be considered in cases of **bradycardia-dependent TdP** but not as an initial general acute treatment [1]. ### Cardiac pacing if necessary - **Cardiac pacing** can be used in cases of **bradycardia-dependent TdP** where severe bradycardia is the trigger or in refractory cases that do not respond to magnesium. - It is **not** typically the **first-line acute treatment** but rather a secondary intervention.

Q: Radiofrequency ablation is commonly performed for which of the following conditions?

Paroxysmal supraventricular tachycardia (PSVT). ***Paroxysmal supraventricular tachycardia (PSVT)*** - **PSVT** is the most common indication for radiofrequency ablation, particularly **AV nodal reentrant tachycardia (AVNRT)**, which accounts for the majority of cases. - RFA has an extremely high success rate (>95%) for PSVT due to the **predictable anatomical circuits** involved, making it the first-line definitive treatment. *Ventricular tachycardia* - While RFA can treat certain types of **monomorphic VT**, it is typically reserved for **drug-refractory cases** or specific structural conditions like **right ventricular outflow tract VT**. - VT often arises from **complex scar tissue** in diseased ventricles, making ablation technically challenging with lower success rates compared to PSVT. *Atrial tachycardia* - **Focal atrial tachycardia** can be treated with RFA, but it represents a less common indication compared to PSVT due to **variable anatomical origins** within the atria. - Success rates are generally lower than PSVT because of the **multiple potential circuits** and difficulty in mapping the exact arrhythmogenic focus. *Wolff-Parkinson-White (WPW) syndrome* - **WPW syndrome** is an anatomical condition with an **accessory pathway** that predisposes to a specific type of PSVT called **AV reentrant tachycardia (AVRT)**. - When RFA is performed for WPW, it is essentially treating the **PSVT caused by the syndrome**, not the syndrome itself - making PSVT the more accurate answer for the arrhythmia being ablated.

Q: Which of the following is the primary feature of Eisenmenger syndrome?

Left-to-right shunt. ***Left-to-right shunt*** - Eisenmenger syndrome begins with a **left-to-right shunt** in congenital heart defects (e.g., VSD, ASD, PDA). This shunt leads to increased pulmonary blood flow and, eventually, **pulmonary hypertension**. [1] - Over time, the sustained pulmonary hypertension causes irreversible damage to the pulmonary vasculature, leading to a reversal of the shunt from left-to-right to **right-to-left**, resulting in cyanosis. [1] *Mitral stenosis* - This condition is a narrowing of the **mitral valve**, which obstructs blood flow from the left atrium to the left ventricle. - While it can cause pulmonary hypertension, it's not a primary feature or precursor to Eisenmenger syndrome, which is defined by an initial congenital shunt. *Atrial septal defect (ASD)* - An ASD is a type of **left-to-right shunt** that can *lead* to Eisenmenger syndrome, but it is not the primary feature *of* the syndrome itself. - The syndrome develops from the physiological consequences of the shunt (pulmonary hypertension and shunt reversal), not from the shunt's anatomical presence alone. [1] *Ventricular septal defect (VSD)* - A VSD is also a type of **left-to-right shunt** that can *cause* Eisenmenger syndrome, but it is the initial anatomical defect, not the primary physiological feature that defines the syndrome. - Eisenmenger syndrome represents the advanced stage where the VSD's hemodynamic impact has caused irreversible pulmonary vascular disease and shunt reversal. [1]

Q: A 38-year-old daily laborer has a heart rate of 44 on routine examination. What is the most appropriate management?

Observation and no immediate treatment required. **Observation and no immediate treatment required** - The patient is a **daily laborer**, suggesting a physically demanding job which can lead to **physiologic bradycardia** due to increased vagal tone. - A heart rate of 44 bpm in an **asymptomatic individual** without other clinical signs of hypoperfusion (e.g., dizziness, lightheadedness, syncope) often requires no immediate intervention [1]. *Atropine* - Atropine is indicated for **symptomatic bradycardia** to increase heart rate by blocking the effects of the vagus nerve. - Since the patient is asymptomatic, there is no immediate indication for pharmacologic intervention with atropine. *Cardiac pacing* - **Temporary or permanent cardiac pacing** is reserved for severe symptomatic bradycardia or bradycardia unresponsive to medications, especially if associated with hemodynamic instability [1]. - An asymptomatic patient with a heart rate of 44 bpm does not meet the criteria for immediate pacing. *Adrenaline* - Adrenaline (epinephrine) is typically used in situations of **cardiac arrest** or profound symptomatic bradycardia unresponsive to atropine. - It is a potent vasoconstrictor and inotrope and is not a first-line agent for asymptomatic bradycardia.

Question 1

Which of the following conditions can lead to an abnormal increase in the amplitude of the 'U' wave on an ECG?

Accepted Answer

Hypokalemia

Answer

Amiodarone

Answer

Quinidine

Answer

None of the options

Question 2

A 28-year-old female presents with progressive dyspnea on exertion and palpitations for the past 6 months. She has a history of recurrent sore throat episodes during childhood. On examination, she has an irregularly irregular pulse, and auscultation reveals a mid-diastolic rumbling murmur at the apex with presystolic accentuation. ECG shows atrial fibrillation with controlled ventricular rate and left atrial enlargement. Echocardiogram demonstrates mitral valve stenosis with commissural fusion, leaflet thickening, and a mitral valve area of 1.2 cm². What is the most likely diagnosis?

Accepted Answer

Rheumatic mitral stenosis

Answer

Neovascularization of the valve leaflets

Answer

Vegetations on the mitral valve

Answer

Myxomatous degeneration of the mitral valve

Question 3

Which of the following statements is true regarding the rheumatization of the mitral valve?

Accepted Answer

Rheumatization of the mitral valve can cause mitral stenosis or regurgitation.

Answer

Rheumatization of the mitral valve can lead to fibrosis and calcification.

Answer

Rheumatization of the mitral valve is always asymptomatic.

Answer

Rheumatization does not affect the mitral valve.

Question 4

Recommended interventions to reduce the incidence of coronary artery disease include the following except which of the following?

Accepted Answer

Fat intake < 20% of total energy.

Answer

Reduce salt intake to < 5g per day.

Answer

No alcohol consumption.

Answer

Dietary cholesterol < 100 mg/1000kcal/d

Question 5

Asynchronous cardioversion is given in:

Accepted Answer

Ventricular fibrillation

Answer

AF

Answer

Atrial flutter

Answer

Ventricular tachycardia

Question 6

A female patient develops chest pain that is not associated with exercise, and chest auscultation shows multiple non-ejection clicks. The investigation used to diagnose the disease is:

Accepted Answer

Echocardiography for mitral valve prolapse

Answer

Pyrophosphate scan for cardiac amyloidosis

Answer

ECG for heart rhythm evaluation

Answer

Thallium 201 scan for myocardial perfusion

Question 7

In a patient with congenital prolonged QT syndrome presenting with intermittent torsades de pointes, which of the following is the first-line acute treatment?

Accepted Answer

Magnesium sulfate

Answer

Beta-blockers

Answer

Isoprenaline for heart rate support

Answer

Cardiac pacing if necessary

Question 8

Radiofrequency ablation is commonly performed for which of the following conditions?

Accepted Answer

Paroxysmal supraventricular tachycardia (PSVT)

Answer

Ventricular tachycardia

Answer

Atrial tachycardia

Answer

Wolff-Parkinson-White (WPW) syndrome

Question 9

Which of the following is the primary feature of Eisenmenger syndrome?

Accepted Answer

Left-to-right shunt

Answer

Mitral stenosis

Answer

Atrial septal defect (ASD)

Answer

Ventricular septal defect (VSD)

Question 10

A 38-year-old daily laborer has a heart rate of 44 on routine examination. What is the most appropriate management?

Accepted Answer

Observation and no immediate treatment required

Answer

Atropine

Answer

Cardiac pacing

Answer

Adrenaline

Cardiology — MCQs

Cardiology — MCQs

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