Cardiology — MCQs

Cardiology Indian Medical PG Practice Questions and MCQs

Question 1621: All of the following may cause ST segment elevation on an EKG, except which of the following?

A. Ventricular aneurysm
B. Prizmetal angina
C. Early repolarization variant
D. Constrictive pericarditis (Correct Answer)

Explanation: ***Constrictive pericarditis*** - While **pericarditis** can cause ST elevation due to inflammation of the epicardial layer [1], **constrictive pericarditis** primarily leads to **reduced diastolic filling** and rarely causes ST elevation. - ECG findings in constrictive pericarditis typically include **low voltage QRS complexes** and **T-wave flattening or inversion**, not ST elevation. *Early repolarization variant* - This is a **benign ECG finding** often seen in young, healthy individuals, characterized by **notching or slurring** at the end of the QRS complex (J-point elevation) with upwardly concave ST segments [1]. - It's a **normal variant** and not indicative of myocardial injury, despite the ST elevation. *Ventricular aneurysm* - A **ventricular aneurysm**, a non-contractile area of myocardial scar tissue, typically results in **persistent ST elevation** after an acute myocardial infarction in the leads corresponding to the aneurysm. - The ST elevation is usually **fixed** and observed in the setting of prior MI. *Prizmetal angina* - Also known as **vasospastic angina**, this condition involves **coronary artery spasm** causing transient myocardial ischemia, which manifests as **ST segment elevation** during episodes of chest pain. - The ST elevation resolves once the spasm ceases, differentiating it from an STEMI.

Question 1622: Which of the following is true about the bicuspid aortic valve?

A. Diagnosis is made by echocardiography (Correct Answer)
B. It is more common in females than in males
C. Post-stenotic dilatation of ascending aorta can be seen
D. Usually undetected in early life

Explanation: ### Diagnosis is made by echocardiography - **Echocardiography** is the gold standard for diagnosing a bicuspid aortic valve, as it allows direct visualization of the valve's morphology and assessment of its function (stenosis or regurgitation). - This imaging modality can identify the **two cusps** instead of the usual three, quantify blood flow, and assess for associated abnormalities. *It is more common in females than in males* - The bicuspid aortic valve is actually **more common in males** than in females, with a male-to-female ratio of about 2:1 to 4:1. - It is one of the **most common congenital heart defects**, affecting approximately 1-2% of the general population. *Usually undetected in early life* - While some cases might be asymptomatic early on, many individuals with a bicuspid aortic valve are diagnosed in **childhood or adolescence** due to associated murmurs or symptoms like chest pain or shortness of breath during exertion. - Its presence often predisposes individuals to complications like **aortic stenosis** [1] or regurgitation [2], which can manifest at any age [2]. *Post-stenotic dilatation of ascending aorta can be seen* - While **post-stenotic dilatation** of the ascending aorta can indeed be seen in patients with a bicuspid aortic valve, this statement on its own is not the most definitive truth about the diagnosis because it describes a complication or associated finding, not the primary method of diagnosis. - Aortic dilatation is a common finding due to **abnormal wall stress** and intrinsic medial weakness, often observed in conjunction with the bicuspid valve.

Question 1623: In a patient with subclavian steal syndrome, what is the most characteristic finding?

A. The flow of blood in the vertebral arteries is normal
B. The BP is decreased on the ipsilateral side (Correct Answer)
C. The patients may present with claudication features in some cases.
D. The patients may present with neurological features.

Explanation: ***The BP is decreased on the ipsilateral side*** - Subclavian steal syndrome is caused by a **stenosis** or **occlusion** of the **subclavian artery** proximal to the origin of the vertebral artery. This leads to reduced blood flow to the ipsilateral arm, resulting in a **decreased blood pressure** in that arm. [1] - The pressure difference between the unaffected and affected arm is typically **greater than 15-20 mmHg**, which is a key diagnostic clue. *The flow of blood in the vertebral arteries is normal* - In subclavian steal syndrome, the blood flow in the **ipsilateral vertebral artery** can be **reversed** or significantly reduced. - This reversal of flow occurs as the vertebral artery "steals" blood from the vertebrobasilar circulation to supply the ischemic arm. *The patients may present with claudication features in some cases.* - While patients can experience **arm claudication** (pain, fatigue, or numbness during exercise) due to reduced blood flow to the arm, this is a symptom rather than the **most characteristic finding** related to the underlying hemodynamics. - Arm claudication occurs when the **demand for blood flow** to the ipsilateral arm muscles exceeds the compromised supply, often during arm exercise. *The patients may present with neurological features.* - Neurological symptoms, such as **dizziness, vertigo, diplopia, or syncope**, can occur due to **vertebrobasilar insufficiency** when blood is "stolen" from the cerebral circulation. - However, the **most characteristic hemodynamic finding** directly reflecting the subclavian artery stenosis is the **blood pressure differential** in the arms.

Question 1624: Extent of cardiotoxicity of chemotherapy and radiotherapy is best diagnosed by:

A. Radionuclide scan
B. ECG
C. Echocardiogram (Correct Answer)
D. Endomyocardial biopsy

Explanation: Echocardiogram - An echocardiogram is the most common and widely used non-invasive diagnostic tool to assess cardiac function and structure, including left ventricular ejection fraction (LVEF), which is crucial for monitoring cardiotoxicity [1]. - It can detect changes in ventricular size, wall motion abnormalities, and valvular function that may arise from chemotherapy or radiotherapy-induced damage [1]. Radionuclide scan - Radionuclide scans, such as MUGA (Multigated Acquisition) scans, can also assess LVEF but involve radiation exposure and are generally reserved for cases where echocardiography is suboptimal or yields equivocal results. - While sensitive, it's not the primary or initial diagnostic test due to its invasive nature and cost compared to echocardiography. ECG - An ECG (electrocardiogram) assesses the electrical activity of the heart but provides limited information about structural or functional changes indicative of cardiotoxicity [2]. - It can detect arrhythmias or ischemic changes but is not specific enough to determine the extent of myocardial damage from chemotherapy or radiotherapy [2]. Endomyocardial biopsy - Endomyocardial biopsy is an invasive procedure that provides a definitive histological diagnosis of myocardial damage but is rarely performed due to its invasiveness, risk of complications, and the availability of less invasive methods. - It is typically reserved for unexplained severe cardiac dysfunction or for specific research protocols, not routine monitoring of cardiotoxicity.

Question 1625: Most common cardiac manifestation of Holt-Oram syndrome is?

A. ASD (Correct Answer)
B. VSD
C. tachycardia
D. PDA

Explanation: ***ASD*** - **Atrial septal defect (ASD)** is the most frequently observed cardiac anomaly in patients with **Holt-Oram syndrome**. - This syndrome is characterized by upper limb abnormalities (especially radial ray defects) and congenital heart disease, with ASD or VSD being the most common defects, but **ASD is more prevalent overall**. *VSD* - **Ventricular septal defect (VSD)** is another common cardiac manifestation in Holt-Oram syndrome, but it occurs less frequently than ASD [1]. - While both are septal defects, **ASD is quantitatively more common** in this specific syndrome [1]. *tachycardia* - **Tachycardia**, or a fast heart rate, is a symptom or sign and not a structural cardiac manifestation itself. - While patients with **congenital heart defects** may experience arrhythmias, tachycardia is not the primary cardiac abnormality defining Holt-Oram syndrome. *PDA* - **Patent ductus arteriosus (PDA)** is a known congenital heart defect but is **not one of the most common** cardiac manifestations associated with Holt-Oram syndrome. - The characteristic defects in Holt-Oram syndrome primarily involve the **atrial and ventricular septa** [1].

Question 1626: Reversed Coarctation is seen in which of the following conditions?

A. Polyarteritis Nodosa
B. Takayasu Arteritis (Correct Answer)
C. Kawasaki Disease
D. Giant cell Arteritis

Explanation: **Takayasu Arteritis** - **Reversed coarctation** (or paradoxical coarctation) is a characteristic feature of **Takayasu arteritis**, where narrowing or occlusion mainly affects the **aortic arch** and its branches, leading to a reversed pressure gradient in the upper extremities compared to the lower extremities. - This condition is a **large-vessel vasculitis** primarily affecting the aorta and its major branches, causing ischemia to the upper body and head. *Polyarteritis Nodosa* - This is a **medium-sized vessel vasculitis** that typically affects renal and visceral arteries, leading to aneurysms and occlusions. - It does not primarily affect the aortic arch or present with reversed coarctation. *Kawasaki Disease* - **Kawasaki disease** is a **medium-sized vessel vasculitis** predominantly affecting children, which can cause coronary artery aneurysms. - It does not involve the large vessels of the aortic arch to cause reversed coarctation. *Giant cell Arteritis* - **Giant cell arteritis (GCA)** is a **large-vessel vasculitis** primarily affecting the aorta and its major branches, but typically involves the **temporal arteries**. - While it can affect the aorta, it is more commonly associated with headaches and jaw claudication, and reversed coarctation is not a prominent feature.

Question 1627: Which of the following rhythms associated with cardiac arrest is considered shockable?

A. Pulseless ventricular tachycardia
B. Asystole
C. Pulseless electrical activity
D. Ventricular fibrillation (Correct Answer)

Explanation: ***Ventricular fibrillation*** - **Ventricular fibrillation (VF)** is a chaotic, disorganized electrical activity in the ventricles, leading to ineffective myocardial contraction and cardiac arrest [1]. - Due to the presence of electrical activity that can be reset, **defibrillation** (an electrical shock) is the definitive treatment to restore a perfusing rhythm [1]. *Asystole* - **Asystole** is characterized by the complete absence of electrical and mechanical activity in the heart, appearing as a "flat line" on the ECG. - Since there is no electrical activity to reorganize, defibrillation is ineffective, and management focuses on **cardiopulmonary resuscitation (CPR)** and medications like epinephrine [2]. *Pulseless electrical activity* - **Pulseless electrical activity (PEA)** involves an organized electrical rhythm on the ECG but no palpable pulse, indicating inadequate cardiac mechanical activity. - Defibrillation is not indicated as there is a rhythmic electrical activity, and treatment focuses on identifying and correcting the underlying causes of **cardiac mechanical failure**. *Pulseless ventricular tachycardia* - While **pulseless ventricular tachycardia (VT)** is a malignant rhythm, the question asks for a rhythm that is *considered shockable* in the context of cardiac arrest. - In actual cardiac arrest algorithms, **pulseless VT** is treated similarly to **ventricular fibrillation** and is indeed shockable [1]. However, if multiple options are given and only one can be chosen, **VF** and **pulseless VT** are both shockable. Given the options, VF is explicitly and commonly cited as a primary shockable rhythm. * Correction: **Pulseless ventricular tachycardia** *is* a shockable rhythm and is treated with immediate defibrillation in cardiac arrest. The initial explanation incorrectly implies it's not. This response should be revised to state that both VF and pulseless VT are shockable. - Both **ventricular fibrillation (VF)** and **pulseless ventricular tachycardia (VT)** are considered shockable rhythms in cardiac arrest algorithms [1]. - Defibrillation is performed to depolarize the cardiac muscle cells simultaneously, allowing the natural pacemaker of the heart to resume control [1].

Question 1628: Which of the following is true about torsades de pointes?

A. Presence of polymorphic QRS complexes
B. It is a type of supraventricular tachycardia
C. QRS complexes appear to rotate around the isoelectric baseline of ECG
D. Presence of prolonged QT interval on ECG (Correct Answer)

Explanation: ***Presence of prolonged QT interval on ECG*** - Torsades de pointes is a polymorphic ventricular tachycardia associated with a **prolonged QT interval**, which often precedes the arrhythmia [1]. - A prolonged QT interval indicates a delayed repolarization of the ventricles, creating a vulnerable period for the development of aberrant electrical activity [2]. *Presence of polymorphic QRS complexes* - While torsades de pointes does exhibit **polymorphic QRS complexes**, this is a characteristic *feature* of the arrhythmia itself, not the primary predisposing factor or defining characteristic that initiates it [1]. - The key underlying condition leading to torsades is the **QT prolongation**. *It is a type of supraventricular tachycardia* - Torsades de pointes is a **ventricular tachycardia**, meaning it originates in the ventricles, not above them in the atria or AV node (supraventricular) [1]. - Its origin below the Bundle of His differentiates it from supraventricular arrhythmias. *QRS complexes appear to rotate around the isoelectric baseline of ECG* - This description accurately depicts the characteristic **"twisting of the points"** morphology of torsades de pointes, but it is a *description of the ECG appearance* during the arrhythmia itself, not the fundamental predisposing factor [1]. - The rotation is a consequence of the changing amplitudes and axes of the polymorphic QRS complexes [1].

Question 1629: Ankle-brachial index is useful in prediction of:

A. All of the options
B. Myocardial infarction (Correct Answer)
C. Buerger's disease
D. Meconium ileus

Explanation: ***Myocardial infarction*** - A low **ankle-brachial index (ABI)** indicates broader **atherosclerotic disease**, which is a significant **risk factor** for **myocardial infarction** and other **cardiovascular events** [1]. - ABI measures arterial insufficiency in the lower extremities; a value less than 0.9 suggests **peripheral artery disease (PAD)**, independently predicting future cardiac events [1]. *Buerger's disease* - Not directly predicted by ABI in the context of general cardiovascular risk; **Buerger's disease** is an **inflammatory vasculitis** primarily affecting small and medium-sized arteries and veins. - While it causes digital ischemia, its etiology and pathophysiology are distinct from the general atherosclerotic burden measured by ABI. *Meconium ileus* - **Meconium ileus** is a **gastrointestinal obstruction** in newborns, typically associated with **cystic fibrosis**, and has no relationship with the **ankle-brachial index** measurement. - ABI is a vascular diagnostic tool, not relevant to pediatric gastrointestinal conditions. *All of the options* - This is incorrect because **meconium ileus** and **Buerger's disease** are not primarily or directly predicted by the ankle-brachial index. - ABI is a strong predictor of systemic atherosclerosis and associated events like myocardial infarction, but not unrelated conditions [1].

Question 1630: Which of the following conditions can lead to an abnormal increase in the amplitude of the 'U' wave on an ECG?

A. Hypokalemia (Correct Answer)
B. Amiodarone
C. Quinidine
D. None of the options

Explanation: ***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.

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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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Cardiology — MCQs

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