Cardiology — MCQs

Cardiology Indian Medical PG Practice Questions and MCQs

Question 1481: Which of the following conditions is a known cause of Right Bundle Branch Block (RBBB)?

A. Myocardial infarction
B. Cor pulmonale (Correct Answer)
C. Normal aging process
D. Pulmonary embolism

Explanation: ### Question Which of the following conditions is a known cause of Right Bundle Branch Block (RBBB)? ### Original Explanation ***Cor pulmonale*** - **Cor pulmonale** is **right ventricular hypertrophy** with or without dilation due to pulmonary hypertension, impacting the right ventricle's conduction system and causing **RBBB** [1]. - The increased pressure and strain on the right side of the heart can damage the right bundle branch, leading to a conduction delay visible as **RBBB** on an ECG [1]. *Normal aging process* - While the **normal aging process** can lead to some degenerative changes in the heart's conduction system, it more commonly causes **Left Anterior Fascicular Block** or **Left Bundle Branch Block (LBBB)**, rather than isolated RBBB. - Significant **RBBB** in an elderly individual often points to an underlying structural or physiological cause rather than mere aging. *Pulmonary embolism* - A **pulmonary embolism** can cause acute **right ventricular strain** and dilation, which can mimic **RBBB** or cause a transient RBBB pattern [1]. - However, **RBBB** is not a direct consequence of the physical obstruction but rather an effect of the resulting **acute pulmonary hypertension** and right heart strain [2]. *Myocardial infarction* - A **myocardial infarction** affecting the **septum** or the **right ventricle** can damage the right bundle branch, leading to **RBBB**. - However, the most classic ECG finding of a myocardial infarction is **ST-segment elevation** or **new Q waves**, with **RBBB** being a potential complication rather than a direct cause [3].

Question 1482: Which of the following is a complication of Takayasu's arteritis?

A. None of the options
B. Intimal fibrosis
C. Renal hypertension (Correct Answer)
D. Coronary aneurysm

Explanation: Renal hypertension - Takayasu's arteritis often causes stenosis of the renal arteries, leading to renovascular hypertension [2]. - This complication arises from the inflammatory thickening and narrowing of large arteries, including those supplying the kidneys [3]. Intimal fibrosis - While intimal fibrosis is a pathological feature seen in Takayasu's arteritis due to chronic inflammation, it is part of the disease process rather than a direct clinical complication. - The fibrosis itself contributes to the stenosis and occlusion that cause clinical complications [1], but it is not a standalone complication. Coronary aneurysm - Though Takayasu's arteritis can affect coronary arteries, it typically causes stenosis or occlusion rather than aneurysm formation. - Coronary aneurysms are more characteristic of diseases like Kawasaki disease [3]. None of the options - This option is incorrect as renal hypertension is a well-known and significant complication of Takayasu's arteritis.

Question 1483: 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 1484: 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.

Question 1485: The normal range for Ankle Brachial Pressure Index (ABI) is:

A. 0.8-0.9 (Mild PAD)
B. 0.5-0.8 (Moderate PAD)
C. >1.3 (Calcified arteries)
D. 1.0-1.3 (Normal) (Correct Answer)

Explanation: **1.0-1.3 (Normal)** - An **ABI** value between 1.0 and 1.3 is considered the normal range, indicating adequate blood flow to the lower extremities. - This range signifies that the **blood pressure** in the ankles is similar to or slightly higher than the blood pressure in the arms, as expected in healthy individuals [1]. * >1.3 (Calcified arteries)* - An **ABI** value greater than 1.3 usually suggests **calcification** and hardening of the arteries, making them incompressible. - This high reading often occurs in patients with **diabetes** or **chronic kidney disease** and can falsely elevate the ABI, potentially masking underlying peripheral artery disease. *0.8-0.9 (Mild PAD)* - An **ABI** in this range indicates **mild peripheral artery disease (PAD)**, where there is some reduction in blood flow, but symptoms might be subtle or only present with exertion. - Patients may experience claudication, but it's typically less severe and could improve with conservative management [1]. *0.5-0.8 (Moderate PAD)* - This range suggests **moderate peripheral artery disease (PAD)**, indicating a more significant blockage or narrowing of the arteries. - Patients often experience **intermittent claudication** and may have discomfort with less strenuous activity [1].

Question 1486: 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 1487: 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 1488: In Left Ventricular Hypertrophy (LVH), what is the minimum value of SV1 + RV6 in mm that suggests the presence of LVH?

A. 25 mm
B. 30 mm
C. 35 mm (Correct Answer)
D. 45 mm

Explanation: 35 mm - A combined amplitude of **SV1 + RV6 ≥ 35 mm** on an ECG is a commonly used **Sokolow-Lyon criterion** for diagnosing LVH. - This criterion demonstrates a degree of **specificity** for LVH, although its sensitivity can be limited. 25 mm - This value is **too low** and would lead to a high number of **false positives** for LVH. - While some criteria consider smaller amplitudes, **25 mm is not a standard threshold** for the Sokolow-Lyon criteria. 30 mm - This value is **below the standard threshold** for the Sokolow-Lyon criteria, potentially leading to underdiagnosis. - The accepted cut-off for **SV1 + RV6** in adults is generally higher than 30 mm. 45 mm - While a value of **45 mm** would strongly suggest LVH, it is **not the minimum threshold** for the Sokolow-Lyon criteria. - Using this higher threshold would decrease sensitivity, potentially **missing some cases** of LVH.

Question 1489: Low QRS voltage on ECG with left ventricular hypertrophy on Echocardiography suggests a diagnosis of:

A. Cardiac Amyloidosis (Correct Answer)
B. Infective endocarditis
C. Cor pulmonale
D. Pericardial effusion

Explanation: ***Cardiac Amyloidosis*** - **Low QRS voltage** on ECG despite echocardiographic evidence of **left ventricular hypertrophy** is a classic paradox seen in cardiac amyloidosis. - Amyloid deposits infiltrate the myocardium, increasing wall thickness but **reducing electrical activity transmission**. *Cor pulmonale* - Cor pulmonale involves **right ventricular hypertrophy** due to pulmonary hypertension, not primarily left ventricular hypertrophy. - While it can cause changes in ECG findings, the combination of low QRS voltage with LVH is not characteristic. *Infective endocarditis* - Infective endocarditis primarily affects heart valves and can cause vegetations, but it does not typically lead to **left ventricular hypertrophy** or **low QRS voltage** on ECG. - ECG findings in endocarditis are often related to conduction abnormalities or ischemia if embolization occurs. *Pericardial effusion* - A significant pericardial effusion can cause **low QRS voltage** on ECG due to the dampening effect of fluid around the heart [1]. - However, it does not typically cause **left ventricular hypertrophy**; rather, it can be associated with signs of tamponade or inflammation [1].

Question 1490: 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.

Practice by Chapter

Coronary Artery Disease and Angina

Practice Questions

Acute Coronary Syndromes

Practice Questions

Heart Failure

Practice Questions

Cardiac Arrhythmias

Practice Questions

Valvular Heart Diseases

Practice Questions

Cardiomyopathies

Practice Questions

Pericardial Diseases

Practice Questions

Congenital Heart Disease in Adults

Practice Questions

Hypertension and Hypertensive Emergencies

Practice Questions

Pulmonary Hypertension

Practice Questions

Non-invasive Cardiac Diagnostics

Practice Questions

Preventive Cardiology

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Cardiology — MCQs

Cardiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?