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: 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: What is the most common type of benign intracavitary cardiac tumor?

Myxoma. ***Myxoma*** - **Cardiac myxoma** is the **most common primary benign tumor of the heart**, accounting for approximately 50% of all primary cardiac tumors. - These tumors typically arise in the **atria, especially the left atrium**, and can cause symptoms due to obstruction of blood flow or embolization. *Leiomyoma* - **Leiomyomas** are benign tumors of **smooth muscle origin** and are most commonly found in the uterus (fibroids) or gastrointestinal tract, not typically in the heart. - While they can occur in the heart, they are exceedingly rare as primary cardiac tumors and are not the most common type. *Sarcoma* - **Sarcomas** are **malignant tumors** originating from mesenchymal tissues, and primary cardiac sarcomas are rare but are the most common type of primary malignant cardiac tumor. - The question specifically asks for a **benign intracavitary cardiac tumor**, ruling out sarcomas. *Lipoma* - **Lipomas** are benign tumors composed of **fat tissue** and can occur in various organs, including the heart. - While cardiac lipomas are found, they are far less common than myxomas and do not represent the most common benign intracavitary cardiac tumor.

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: ECG is poor in detecting ischemia in areas supplied by which of the following vessels?

Left Circumflex (LCx). ***Left Circumflex (LCx)*** - Ischemia in the area supplied by the **LCx artery** often occurs in the **posterior or lateral wall** of the left ventricle, which can be difficult to detect with standard 12-lead ECGs. - ECG leads that best view the LCx territory (V7-V9) are not routinely performed, leading to a higher chance of **silent or unrecognized ischemia**. *Left Anterior Descending (LAD)* - The LAD supplies the **anterior and septal walls** of the left ventricle, areas well-covered by standard ECG leads like V1-V4 [1][2]. - Ischemia in the LAD territory typically produces clear changes such as **ST-segment elevation** or **T-wave inversions** in these leads [2]. *Posterior Descending Artery (PDA)* - The PDA supplies the **inferior wall** and a portion of the posterior septum. - Ischemia in this area is generally well-detected by inferior leads (II, III, aVF) on a standard ECG, showing **ST-segment changes**. *Right Coronary Artery (RCA)* - The RCA typically supplies the **right ventricle** and, in most people, the **inferior wall** of the left ventricle via the PDA. - Ischemia due to RCA occlusion is usually visible in the **inferior leads** (II, III, aVF) and sometimes in **right precordial leads** (V3R, V4R) for right ventricular involvement.

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.

Q: Which one of the following is a major criterion in Jones' criteria for rheumatic fever?

Sydenham's chorea. **Sydenham's chorea** - **Sydenham's chorea** is a neurological manifestation of rheumatic fever, characterized by **involuntary, jerky movements**, and is considered a major criterion [1]. - It results from inflammation of the **basal ganglia** and is unique to rheumatic fever among the acute manifestations [1]. *Carditis* - While **carditis** is a major criterion, it manifests as inflammation of the **heart muscle, valves, or pericardium** [1]. - This option is incorrect because Sydenham's chorea is also a major criterion and an example of one, making it a valid answer for the question. *Subcutaneous nodules* - **Subcutaneous nodules** are firm, painless nodules found over bony prominences. - They are considered a **minor criterion** in Jones' criteria for rheumatic fever. *High ESR* - **High ESR (Erythrocyte Sedimentation Rate)** is a non-specific inflammatory marker. - It is classified as a **minor criterion** in Jones' criteria, indicating general inflammation not unique to rheumatic fever.

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

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 3

Asynchronous cardioversion is given in:

Accepted Answer

Ventricular fibrillation

Answer

AF

Answer

Atrial flutter

Answer

Ventricular tachycardia

Question 4

What is the most common type of benign intracavitary cardiac tumor?

Accepted Answer

Myxoma

Answer

Leiomyoma

Answer

Sarcoma

Answer

Lipoma

Question 5

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 6

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 7

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 8

ECG is poor in detecting ischemia in areas supplied by which of the following vessels?

Accepted Answer

Left Circumflex (LCx)

Answer

Left Anterior Descending (LAD)

Answer

Posterior Descending Artery (PDA)

Answer

Right Coronary Artery (RCA)

Question 9

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

Question 10

Which one of the following is a major criterion in Jones' criteria for rheumatic fever?

Accepted Answer

Sydenham's chorea

Answer

Prolonged PR interval

Answer

High ESR

Answer

Fever

Cardiology — MCQs

Cardiology — MCQs

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