Cardiology — MCQs
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Which of the following is least likely to be associated with broad complex tachycardia due to ventricular tachycardia?
Which of the following is not a high-pitched heart sound?
Wide QRS complex (≥ 0.12 seconds) can be seen in various conditions. Which of the following is least likely to present with a wide QRS complex?
Most common cardiac defect in Turner syndrome
Treatment of asymptomatic bradycardia is
What are the potential clinical consequences of a large patent ductus arteriosus (PDA)?
Most common cause of unilateral pedal edema
LBBB is seen with all except
The S2 heart sound is best appreciated in:
What does a -30 to -90 degree axis deviation indicate?
Cardiology Indian Medical PG Practice Questions and MCQs
Question 1481: Which of the following is least likely to be associated with broad complex tachycardia due to ventricular tachycardia?
- A. Fusion beats
- B. Capture beats
- C. AV dissociation
- D. Termination of tachycardia by carotid sinus massage (Correct Answer)
Explanation: ***Termination of tachycardia by carotid sinus massage*** - **Carotid sinus massage** typically slows or terminates **supraventricular tachycardias (SVTs)** by increasing vagal tone to the AV node. - While it might occasionally slow the ventricular rate in VT (if the SA node is still firing normally), it is very **unlikely to terminate** a re-entrant ventricular tachycardia itself [2]. *Fusion beats* - These occur when an impulse from the ventricles (VT) and an impulse from the atria (often sinus) depolarize the ventricles **simultaneously**, creating a QRS complex that is a blend of the two [1]. - Their presence is a strong indicator of **ventricular tachycardia** [1]. *AV dissociation* - This refers to the atria and ventricles beating independently, where the atrial rate is usually slower than the ventricular rate in VT [1]. - It is a **hallmark sign** of ventricular tachycardia, distinguishing it from most SVTs with aberrancy [1]. *Capture beats* - A capture beat occurs when an atrial impulse (often a sinus beat) successfully conducts through the AV node and depolarizes the ventricles during VT. - This results in a **narrower QRS complex** appearing periodically within the broad complex tachycardia, providing strong evidence for VT.
Question 1482: Which of the following is not a high-pitched heart sound?
- A. Mid-systolic click
- B. Opening snap
- C. Tumor plop sound (Correct Answer)
- D. Pericardial friction rub
Explanation: ***Tumor plop sound*** - This sound, often associated with a **left atrial myxoma**, is typically a **low-pitched, thudding sound** caused by the tumor prolapsing into the left ventricle during diastole. - Its **low frequency** differentiates it from other high-pitched clicks or snaps. *Mid-systolic click* - This sound is a **high-pitched** event, commonly associated with the sudden tensing of **chordae tendineae** or abnormal leaflet motion in **mitral valve prolapse** [1]. - Its high frequency is characteristic of rapid tensing of intracardiac structures. *Opening snap* - An **opening snap** is a **high-pitched** diastolic sound caused by the abrupt opening of a **stenotic mitral valve** [1]. - The sound is generated by the sudden tensing of the fused valve leaflets, which creates a sharp sound. *Pericardial friction rub* - A **pericardial friction rub** is characterized by a high-pitched, scratchy, and often **creaky sound** heard in pericarditis. - It is created as inflamed visceral and parietal pericardial layers rub against each other, producing a high-frequency sound.
Question 1483: Wide QRS complex (≥ 0.12 seconds) can be seen in various conditions. Which of the following is least likely to present with a wide QRS complex?
- A. Left Anterior Fascicular Block (Correct Answer)
- B. Hyperkalemia
- C. Wolf Parkinson White Syndrome
- D. Ventricular Tachycardia
Explanation: ***Left Anterior Fascicular Block*** - While a **Left Anterior Fascicular Block (LAFB)** does affect ventricular depolarization, it typically causes a **left axis deviation** and only *slight widening* of the QRS complex, usually less than 0.12 seconds. - The delay in conduction is primarily through one of the fascicles of the left bundle branch, not the entire ventricular conduction system. *Hyperkalemia* - Severe **hyperkalemia** can significantly impair myocardial conduction, leading to a **diffuse slowing of ventricular depolarization**. - This results in a **widened QRS complex** as the potassium levels increase, along with peaked T waves and eventually sine wave patterns. *Wolf Parkinson White Syndrome* - **Wolff-Parkinson-White (WPW) syndrome** involves an **accessory pathway** that bypasses the AV node, leading to pre-excitation of the ventricles [1, 2]. - This abnormal conduction pathway results in a **short PR interval** and a **delta wave**, which combines with normal ventricular activation to produce a **wide QRS complex** [2]. *Ventricular Tachycardia* - **Ventricular tachycardia (VT)** originates in the ventricles, bypassing the normal His-Purkinje system [3]. - This abnormal ventricular activation sequence leads to a **markedly widened QRS complex** (typically > 0.12 seconds) due to slow, muscle-to-muscle conduction [3].
Question 1484: Most common cardiac defect in Turner syndrome
- A. VSD
- B. ASD
- C. TOF
- D. Coarctation of aorta (Correct Answer)
Explanation: ***Coarctation of aorta*** - **Coarctation of the aorta** is the most frequent cardiac defect found in individuals with **Turner syndrome**, occurring in approximately 10-20% of cases [1]. - This congenital narrowing of the aorta typically presents with **hypertension in the upper extremities** and diminished or absent pulses in the lower extremities [1]. *VSD* - **Ventricular septal defects (VSDs)** are common congenital heart defects but are not the *most common* defect associated with Turner syndrome. - VSDs involve a hole in the wall separating the two lower chambers of the heart, resulting in a **left-to-right shunt**. *ASD* - **Atrial septal defects (ASDs)** are relatively common congenital heart defects but are less frequent in Turner syndrome compared to coarctation of the aorta [2]. - An ASD involves a hole in the wall separating the two upper chambers of the heart, leading to a **left-to-right shunt**. *TOF* - **Tetralogy of Fallot (TOF)** is a complex congenital heart defect involving four specific abnormalities, but it is **rarely associated with Turner syndrome**. - TOF typically presents with **cyanosis** and can be diagnosed by an abnormal heart murmur and characteristic findings on echocardiography.
Question 1485: Treatment of asymptomatic bradycardia is
- A. No treatment is required (Correct Answer)
- B. Give atropine
- C. Isoprenaline
- D. Cardiac pacing
Explanation: **No treatment is required** - **Asymptomatic bradycardia** generally indicates that the heart rate, though slow, is sufficient to meet the body's metabolic demands. - Intervening in the absence of symptoms could be unnecessary and potentially introduce risks without clear benefit [2]. *Give atropine* - **Atropine** is typically used for **symptomatic bradycardia** (e.g., hypotension, altered mental status, chest pain) to increase heart rate by blocking parasympathetic action. - In an asymptomatic patient, its use is not indicated and could lead to side effects like tachycardia or urinary retention. *Isoprenaline* - **Isoprenaline** is a non-selective beta-agonist used to increase heart rate and contractility, often in severe bradycardia or heart block. - Like atropine, its use is reserved for **symptomatic bradycardia** or specific emergency situations, not for asymptomatic conditions. *Cardiac pacing* - **Cardiac pacing** (either temporary or permanent) is indicated for **symptomatic bradycardia** that is refractory to pharmacological treatment or for certain types of heart block [1]. - It is an invasive procedure and is not appropriate for a patient who is asymptomatic.
Question 1486: What are the potential clinical consequences of a large patent ductus arteriosus (PDA)?
- A. All of the listed complications are potential consequences of PDA, depending on the clinical scenario. (Correct Answer)
- B. Endocarditis
- C. Eisenmenger syndrome
- D. Congestive heart failure (CHF)
Explanation: A large **patent ductus arteriosus (PDA)** can lead to several serious clinical consequences due to the continuous left-to-right shunt. The severity and manifestation of these outcomes depend on the size of the PDA and the patient's individual response [1]. Potential complications include **congestive heart failure**, **pulmonary hypertension** progressing to **Eisenmenger syndrome**, and an increased risk of **infective endocarditis**. *Endocarditis* - The abnormal blood flow through a PDA creates **turbulent jets** that can damage the endothelial lining of the pulmonary artery or the ductus itself. - This damaged endothelium is susceptible to bacterial colonization, leading to **infective endocarditis**. *Eisenmenger syndrome* - A large PDA causes a **significant left-to-right shunt**, leading to chronic **pulmonary overcirculation** and increased pulmonary artery pressure. - Over time, this can lead to irreversible **pulmonary vascular disease** and the development of **Eisenmenger syndrome**, characterized by reversed shunt direction [1]. *Congestive heart failure (CHF)* - The continuous flow of blood from the aorta to the pulmonary artery through a large PDA increases the **volume load** on the left ventricle and the pulmonary circulation [1]. - This increased workload eventually leads to **left ventricular dilation** and dysfunction, resulting in symptoms of **congestive heart failure** such as tachypnea, poor feeding, and growth failure in infants [1].
Question 1487: Most common cause of unilateral pedal edema
- A. Pregnancy
- B. Lymphedema
- C. Venous insufficiency (Correct Answer)
- D. Milroy disease
Explanation: ***Venous insufficiency*** - Chronic venous insufficiency is characterized by impaired venous return, leading to **increased hydrostatic pressure** in the capillaries of the lower extremities [2]. - This increased pressure forces fluid out of the capillaries into the interstitial space, causing **unilateral edema, especially in the ankle and foot** [1], [2]. *Pregnancy* - Pregnancy typically causes **bilateral pedal edema** due to increased blood volume, venous compression by the gravid uterus, and hormonal changes. - It would not usually present as a primary cause of *unilateral* pedal edema. *Lymphedema* - Lymphedema results from impaired lymphatic drainage, leading to the **accumulation of protein-rich fluid** in the interstitial space. - While it can be unilateral and cause significant swelling, **venous insufficiency is more common** as a primary cause of unilateral pedal edema. *Milroy disease* - Milroy disease is a **rare, inherited form of primary lymphedema** that typically presents at birth or in early childhood. - It is characterized by **congenital aplasia or hypoplasia of lymphatic vessels** and is not the most common cause of unilateral pedal edema in the general population.
Question 1488: LBBB is seen with all except
- A. Acute Myocardial Infarction (MI)
- B. Hypokalemia (low potassium levels) (Correct Answer)
- C. Hyperkalemia (high potassium levels)
- D. Ashman phenomenon (aberrant conduction in atrial fibrillation)
Explanation: ***Hypokalemia (low potassium levels)*** - **Hypokalemia** does not typically cause LBBB. Instead, it can lead to **QT prolongation**, **U waves**, and flattened T waves, and may predispose to arrhythmias like **torsades de pointes** [3]. - While electrolyte imbalances can affect cardiac conduction, LBBB is primarily associated with structural heart disease or conditions that directly impact the left bundle branch [1]. *Acute Myocardial Infarction (MI)* - **Acute MI**, particularly anterior or septal MIs, can damage the **left bundle branch**, leading to new-onset LBBB [2]. - New LBBB in the setting of acute MI often indicates a **large infarction** and is associated with a worse prognosis [2]. *Hyperkalemia (high potassium levels)* - **Severe hyperkalemia** can cause a variety of ECG changes, including **widening of the QRS complex**, which can mimic LBBB or lead to other intraventricular conduction delays. - As potassium levels rise, the ECG can progress from tall peaked T waves to a wide QRS, flattened P waves, and ultimately a **sine wave pattern** and asystole. *Ashman phenomenon (aberrant conduction in atrial fibrillation)* - The **Ashman phenomenon** is a form of aberrant ventricular conduction, typically seen during **atrial fibrillation**. It refers to a wide QRS complex that occurs after a short R-R interval preceded by a long R-R interval. - This phenomenon often exhibits a morphology consistent with **right bundle branch block (RBBB)**, but can occasionally present with a LBBB-like morphology due to differences in refractory periods of the bundle branches.
Question 1489: The S2 heart sound is best appreciated in:
- A. 2nd right intercostal space (Correct Answer)
- B. 4th left intercostal space
- C. 5th left intercostal space
- D. 3rd left intercostal space
Explanation: ***2nd right intercostal space*** - The **S2 heart sound** is produced primarily by the closure of the **aortic and pulmonic valves** [1]. - The **aortic component (A2)** is best heard at the **right upper sternal border** (2nd right intercostal space), where the aorta is closest to the chest wall [2]. *4th left intercostal space* - This area is typically associated with the **tricuspid valve area**, where tricuspid murmurs and S3/S4 sounds related to the right ventricle can be more prominent. - While heart sounds can be heard here, it is not the primary location for appreciating the S2 sound. *5th left intercostal space* - This is the **mitral area** or **apex**, where the apical impulse is felt and the S1 heart sound (mitral component) is best heard [2]. - The S2 sound is much less prominent here compared to the base of the heart. *3rd left intercostal space* - This is often referred to as **Erb's point**, where murmurs of both aortic and pulmonic origin can sometimes be heard. - While S2 can be heard here, the **2nd right intercostal space** is superior for primarily appreciating the aortic component of S2, and the 2nd left intercostal space for the pulmonic component [2].
Question 1490: What does a -30 to -90 degree axis deviation indicate?
- A. Left Axis Deviation (Correct Answer)
- B. Right Axis Deviation
- C. Normal Cardiac Axis
- D. Extreme Right Axis Deviation
Explanation: ***Left Axis Deviation*** - A cardiac axis between **-30 and -90 degrees** is defined as **Left Axis Deviation (LAD)** [1]. - LAD is typically caused by conditions such as **left ventricular hypertrophy**, **inferior myocardial infarction**, or **left anterior fascicular block**. *Right Axis Deviation* - Right Axis Deviation generally refers to an axis between **+90 and +180 degrees**. - It is often associated with conditions like **right ventricular hypertrophy** or **left posterior fascicular block**. *Extreme Right Axis Deviation* - **Extreme Right Axis Deviation**, sometimes called "Northwest axis," indicates an axis between **-90 and -180 degrees**. - This is a rare finding, usually associated with severe conditions such as **ventricular tachycardia** or **pulmonary embolism**. *Normal Cardiac Axis* - A **normal cardiac axis** typically falls between **-30 and +90 degrees** [1]. - The given range of **-30 to -90 degrees** extends beyond the normal range, indicating an abnormal deviation.
Practice by Chapter
Coronary Artery Disease and Angina
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Acute Coronary Syndromes
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Heart Failure
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Cardiac Arrhythmias
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Valvular Heart Diseases
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Cardiomyopathies
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Pericardial Diseases
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Congenital Heart Disease in Adults
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Hypertension and Hypertensive Emergencies
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Pulmonary Hypertension
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Non-invasive Cardiac Diagnostics
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Preventive Cardiology
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