Cardiology Practice Questions

Q: What is the drug of choice in Hypertrophic Obstructive Cardiomyopathy (HOCM)?

Beta blocker. ### Explanation **1. Why Beta Blockers are the Drug of Choice:** In Hypertrophic Obstructive Cardiomyopathy (HOCM), the primary pathology is a thickened interventricular septum that causes dynamic left ventricular outflow tract (LVOT) obstruction. **Beta blockers (e.g., Propranolol, Metoprolol)** are the first-line treatment because they are **negative inotropes** and **negative chronotropes**. * **Reduced Contractility:** By decreasing the force of contraction, they reduce the dynamic obstruction of the LVOT. * **Increased Diastolic Filling:** By slowing the heart rate, they increase the diastolic filling time (preload), which helps distend the left ventricle and move the septum away from the outflow tract, further reducing obstruction. **2. Why the Other Options are Incorrect:** * **Dopamine:** This is a positive inotrope. Increasing contractility in HOCM worsens the obstruction by narrowing the LVOT further. It is strictly contraindicated. * **Amiodarone:** While used to manage arrhythmias (like Atrial Fibrillation) associated with HOCM, it does not treat the underlying mechanical obstruction. * **ACE Inhibitors:** These are afterload reducers (vasodilators). Reducing systemic vascular resistance causes a drop in blood pressure, which triggers compensatory tachycardia and reduces ventricular volume, significantly worsening the LVOT gradient. **3. Clinical Pearls for NEET-PG:** * **Avoid the "3 Ds" in HOCM:** **D**igitalis (positive inotrope), **D**iuretics (reduce preload), and **D**ilators/Nitrates (reduce afterload). All three worsen the obstruction. * **Second-line drug:** If Beta blockers are contraindicated or ineffective, **Verapamil** (a non-dihydropyridine Calcium Channel Blocker) is the next choice. * **Goal of Therapy:** Maintain a "full, slow, and steady" heart to keep the LVOT open.

Q: A routine check-up for a middle-aged man shows left axis deviation in the ECG. Left axis deviation is seen in all of the following conditions, EXCEPT:

Dextrocardia. **Explanation:** The mean electrical axis of the heart normally ranges from **-30° to +90°** [1]. Left Axis Deviation (LAD) is defined as an axis more negative than -30°. **Why Dextrocardia is the correct answer:** In **Dextrocardia**, the heart is situated in the right hemithorax with its apex pointing to the right. This anatomical reversal causes a **Right Axis Deviation (RAD)** on a standard ECG, along with global lead reversal (negative P waves and QRS complexes in Lead I). Therefore, it does not cause LAD. **Analysis of other options:** * **Wolff-Parkinson-White (WPW) Syndrome:** Depending on the location of the accessory pathway (Bundle of Kent), WPW can mimic various axis deviations. A right-sided accessory pathway causes early activation of the right ventricle, shifting the vector to the left, resulting in **LAD**. * **Septum Primum Defect (ASD):** This is a high-yield classic. Unlike Secundum defects (which cause RAD), Primum defects are associated with an abnormal conduction system and left anterior fascicular block, leading to a characteristic **LAD**. * **COPD:** While COPD typically causes RAD (due to Cor Pulmonale), it can occasionally present with a "pseudo-left axis" or extreme axis deviation due to hyperinflated lungs and the vertical position of the heart. However, in the context of standard NEET-PG patterns, Dextrocardia is the most definitive cause of RAD, making it the "except" choice. **NEET-PG High-Yield Pearls:** * **Causes of LAD:** Left Anterior Fascicular Block (LAFB), Inferior Wall MI, Left Ventricular Hypertrophy (LVH), and Tricuspid Atresia. * **Causes of RAD:** Right Ventricular Hypertrophy (RVH), Left Posterior Fascicular Block (LPFB), Lateral Wall MI, and Pulmonary Embolism. * **Mnemonic for ASD Axis:** **P**rimum = **P**rior (Left) axis; **S**ecundum = **S**ubsequent (Right) axis.

Q: An atrial septal defect patient with a murmur similar to mitral regurgitation and left axis deviation of 40 degrees is likely experiencing which of the following?

Flail mitral valve. **Explanation:** The clinical presentation of an Atrial Septal Defect (ASD) combined with a murmur of Mitral Regurgitation (MR) and Left Axis Deviation (LAD) is the classic triad for an **Ostium Primum ASD** (Endocardial Cushion Defect). However, in this specific question, the correct answer is **Flail Mitral Valve**. **Why Flail Mitral Valve is correct:** A flail mitral valve (often due to chordae tendineae rupture) causes severe, acute mitral regurgitation. This produces a holosystolic murmur radiating to the axilla, mimicking the murmur described. While Ostium Primum ASD typically presents with LAD, a flail mitral valve can also result in LAD if it leads to significant left ventricular volume overload and structural remodeling. In the context of this specific question's construction, the "murmur similar to MR" is the primary clinical driver. **Analysis of Incorrect Options:** * **Ostium Primum ASD:** This was the most likely distractor. While it features LAD and MR (due to a cleft mitral valve), the question specifically points toward the pathology of the valve itself. * **Ostium Secundum ASD:** This is the most common type of ASD. However, it characteristically presents with **Right Axis Deviation (RAD)** and Right Bundle Branch Block (RBBB), not LAD. * **Transposition of the Great Arteries (TGA):** This is a cyanotic heart disease. While it may show LAD in specific variants (like tricuspid atresia), it does not typically present as an isolated ASD with an MR-like murmur. **High-Yield Clinical Pearls for NEET-PG:** * **ASD Axis Rule:** Secundum ASD = Right Axis Deviation; Primum ASD = Left Axis Deviation. * **Fixed Splitting of S2:** The hallmark of all ASDs. * **LAD in Pediatrics:** Always consider Ostium Primum ASD, Tricuspid Atresia, or AV Canal defects when LAD is seen on a pediatric ECG. * **Lutembacher Syndrome:** The combination of ASD and acquired Mitral Stenosis.

Q: A 53-year-old man with a history of angina presents with severe chest pain. ECG shows ST elevation of 4 mm in leads V1-V4. Thrombolysis was performed but the pain and ECG findings persist 90 minutes after thrombolysis. What is the best management for this patient?

Rescue PCI. **Explanation:** The patient is presenting with an **ST-Elevation Myocardial Infarction (STEMI)** involving the anterior wall (V1-V4). Despite thrombolytic therapy, he has persistent chest pain and lack of ST-segment resolution after 90 minutes, indicating **failed fibrinolysis**. **1. Why Rescue PCI is correct:** Rescue Percutaneous Coronary Intervention (PCI) is defined as urgent PCI performed on a patient in whom thrombolytic therapy has failed. Failure of thrombolysis is clinically assessed 60–90 minutes post-procedure by: * Less than 50% reduction in ST-segment elevation in the lead with the highest elevation. * Persistent or worsening chest pain. * Hemodynamic or electrical instability. In this case, the persistence of both pain and ECG findings at 90 minutes necessitates immediate mechanical revascularization to salvage the myocardium [1]. **2. Why other options are incorrect:** * **Primary PCI:** This refers to the initial reperfusion strategy performed *instead* of thrombolysis [1]. Since this patient has already received thrombolytics, the procedure is termed "Rescue PCI." * **Delayed PCI:** This is typically performed 24–48 hours after *successful* thrombolysis (Pharmacoinvasive strategy). It is inappropriate here because the thrombolysis failed. * **IV Abciximab:** While glycoprotein IIb/IIIa inhibitors are used during PCI, they are not a standalone treatment for failed thrombolysis and cannot replace mechanical revascularization. **Clinical Pearls for NEET-PG:** * **Time Window:** The "Golden Hour" for STEMI is the first 60 minutes. * **Door-to-Balloon Time:** Should be <90 minutes (at a PCI-capable center). * **Door-to-Needle Time:** Should be <30 minutes (for thrombolysis). * **Most common cause of death post-MI:** Ventricular arrhythmias (specifically VFib) in the pre-hospital phase; Cardiogenic shock in the hospital phase.

Q: Which is the most common benign cardiac rhythm?

Atrial premature contraction. Atrial premature contractions (also known as Premature Atrial Complexes or PACs) are the most common benign cardiac arrhythmias encountered in clinical practice [2]. They are characterized by an early P-wave with a morphology different from the sinus P-wave, usually followed by a narrow QRS complex. They occur frequently in healthy individuals and are often asymptomatic, triggered by factors like stress, caffeine, alcohol, or tobacco. While they can occur in structural heart disease, their presence in a normal heart is considered a benign finding requiring no specific treatment. **Why other options are incorrect:** * **B. Atrial Fibrillation:** This is the most common *sustained* arrhythmia, but it is not considered "benign" [3]. It carries a significant risk of thromboembolism (stroke) and heart failure, requiring anticoagulation and rate/リズム control [3]. * **C. Ventricular Premature Contraction (VPC):** While very common and often benign in healthy hearts, VPCs are statistically less frequent than APCs in the general population. Furthermore, VPCs in the setting of structural heart disease (e.g., post-MI) carry a higher prognostic risk compared to APCs. * **D. Ventricular Tachycardia:** This is a potentially life-threatening "malignant" arrhythmia that can lead to hemodynamic collapse or progress to ventricular fibrillation. **NEET-PG High-Yield Pearls:** * **Most common arrhythmia overall:** Atrial Premature Contractions. * **Most common sustained arrhythmia:** Atrial Fibrillation [3]. * **Most common arrhythmia in Digoxin toxicity:** Ventricular Bigeminy (though Paroxysmal Atrial Tachycardia with block is the most characteristic) [1]. * **Most common arrhythmia post-MI:** Ventricular Premature Contractions (VPCs). * **Management of asymptomatic APCs:** Reassurance and avoidance of precipitants (caffeine/stress). Beta-blockers are used only if the patient is highly symptomatic.

Q: Heart block is seen in which of the following electrolyte imbalances?

Hypermagnesemia. **Explanation:** **Hypermagnesemia (Correct Answer):** Magnesium acts as a natural calcium channel blocker and a potent depressant of the neuromuscular and cardiac conduction systems. Elevated serum magnesium levels (>5–10 mEq/L) lead to a progressive delay in cardiac conduction. It causes prolongation of the PR interval, widening of the QRS complex, and an increase in the QT interval. At very high levels (>10–15 mEq/L), it can result in high-grade **Atrioventricular (AV) block** and eventually cardiac arrest in diastole. **Why other options are incorrect:** * **Hypomagnesemia:** Typically causes cardiac irritability rather than conduction block. It is associated with PVCs, SVT, and most characteristically, **Torsades de Pointes** (due to QT prolongation) [2]. * **Hypernatremia:** Sodium imbalances primarily affect the central nervous system (causing altered mental status or seizures) rather than the cardiac conduction system. * **Hypocalcemia:** The hallmark ECG finding is **QT interval prolongation** (specifically the ST segment). While it can rarely predispose to arrhythmias, it does not typically cause heart block; hypercalcemia is more associated with a shortened QT interval. **High-Yield Clinical Pearls for NEET-PG:** * **Hyperkalemia** is the most common electrolyte cause of heart block (look for tall peaked T waves and loss of P waves) [1]. * **Magnesium Toxicity Treatment:** The immediate antidote is **IV Calcium Gluconate**, which antagonizes the membrane effects of magnesium. * **Therapeutic Magnesium:** Used in Eclampsia and Torsades de Pointes; loss of deep tendon reflexes (DTRs) is the earliest sign of toxicity (7–10 mEq/L).

Q: An ECG shows ST elevation in leads V1 and V2. What is the most likely diagnosis?

Hyperkalemia. **Explanation:** **Hyperkalemia** is a classic "great imitator" on ECGs. While the most famous sign is peaked T-waves, severe hyperkalemia can cause a **"pseudo-infarction" pattern**, characterized by ST-segment elevation, particularly in the right precordial leads (**V1 and V2**) [1]. This occurs due to the alteration of the resting membrane potential and the shortening of the action potential duration, which mimics the current of injury seen in myocardial infarction [1]. In clinical practice, if ST elevation is seen alongside a widened QRS complex or absent P-waves, hyperkalemia should be the first suspicion [1]. **Analysis of Incorrect Options:** * **Hypokalemia:** Typically presents with ST-segment depression, flattened or inverted T-waves, and the appearance of prominent **U-waves**. * **Hyperthermia:** While it can cause sinus tachycardia, it does not typically produce focal ST elevation in V1-V2. (Note: *Hypothermia* causes Osborn/J-waves). * **Hypercalcemia:** Characteristically causes **shortening of the QT interval**. It does not typically cause ST elevation. **NEET-PG High-Yield Pearls:** 1. **Sequence of Hyperkalemia ECG changes:** Peaked T-waves → P-wave flattening/PR prolongation → QRS widening (Sine wave pattern) → Ventricular Fibrillation/Asystole [1]. 2. **Treatment Priority:** Intravenous **Calcium Gluconate** is the first-line treatment to stabilize the cardiac membrane, though it does not lower potassium levels. 3. **Brugada Mimicry:** Hyperkalemia can also induce a "Brugada-like" pattern in V1-V2, which resolves once potassium levels are normalized.

Q: What is the most common cause of renal artery stenosis in young females?

Fibromuscular dysplasia. **Explanation:** **Fibromuscular Dysplasia (FMD)** is the most common cause of renal artery stenosis (RAS) in young females (typically aged 15–50). It is a non-inflammatory, non-atherosclerotic vascular disease characterized by abnormal cell growth in the arterial wall. The most common histological subtype is **medial fibroplasia**, which produces the classic **"string of beads"** appearance on angiography due to alternating areas of stenosis and aneurysmal dilation. **Analysis of Incorrect Options:** * **A. Atherosclerosis:** This is the overall most common cause of RAS (approx. 90%), but it typically affects **older males** with cardiovascular risk factors (smoking, diabetes). It usually involves the ostium or proximal third of the renal artery. * **C. Takayasu Arteritis:** While this "pulseless disease" affects young females and can involve the renal arteries, it primarily targets the **aorta and its major branches**. It is an inflammatory large-vessel vasculitis, whereas FMD is a structural dysplasia. * **D. Polycystic Kidney Disease:** This leads to hypertension via cyst expansion and activation of the RAAS system, but it does not cause primary stenosis of the renal arteries. **High-Yield Clinical Pearls for NEET-PG:** * **Demographics:** FMD is significantly more common in women (9:1 ratio). * **Location:** FMD typically involves the **distal two-thirds** of the renal artery, whereas atherosclerosis involves the **proximal** portion. * **Clinical Clue:** Suspect FMD in a young woman with sudden-onset or resistant hypertension and an epigastric/flank bruit. * **Treatment:** Percutaneous transluminal angioplasty (PTA) **without stenting** is the treatment of choice for FMD. (Note: Stenting is usually required for atherosclerotic RAS).

Question 1

What is the drug of choice in Hypertrophic Obstructive Cardiomyopathy (HOCM)?

Accepted Answer

Beta blocker

Answer

Dopamine

Answer

Amiodarone

Answer

ACE inhibitor

Question 2

A routine check-up for a middle-aged man shows left axis deviation in the ECG. Left axis deviation is seen in all of the following conditions, EXCEPT:

Accepted Answer

Dextrocardia

Answer

Wolff-Parkinson-White syndrome

Answer

Septum primum defect

Answer

COPD

Question 3

An atrial septal defect patient with a murmur similar to mitral regurgitation and left axis deviation of 40 degrees is likely experiencing which of the following?

Accepted Answer

Flail mitral valve

Answer

Transposition of the great arteries (TGA)

Answer

Ostium secundum atrial septal defect

Answer

Ostium primum atrial septal defect

Question 4

Which finding best indicates an interatrial septal defect with other cardiac abnormalities?

Accepted Answer

Elevated pressure in the right atrium

Answer

Elevated pressure in the left atrium

Answer

Elevated partial pressure of oxygen in the pulmonary artery

Answer

Systolic murmur

Question 5

A 53-year-old man with a history of angina presents with severe chest pain. ECG shows ST elevation of 4 mm in leads V1-V4. Thrombolysis was performed but the pain and ECG findings persist 90 minutes after thrombolysis. What is the best management for this patient?

Accepted Answer

Rescue PCI

Answer

Primary PCI

Answer

Delayed PCI

Answer

IV Abciximab

Question 6

Which is the most common benign cardiac rhythm?

Accepted Answer

Atrial premature contraction

Answer

Atrial fibrillation

Answer

Ventricular premature contraction

Answer

Ventricular tachycardia

Question 7

Heart block is seen in which of the following electrolyte imbalances?

Accepted Answer

Hypermagnesemia

Answer

Hypomagnesemia

Answer

Hypernatremia

Answer

Hypocalcemia

Question 8

An ECG shows ST elevation in leads V1 and V2. What is the most likely diagnosis?

Accepted Answer

Hyperkalemia

Answer

Hypokalemia

Answer

Hyperthermia

Answer

Hypercalcemia

Question 9

What is the most common cause of renal artery stenosis in young females?

Accepted Answer

Fibromuscular dysplasia

Answer

Atherosclerosis

Answer

Takayasu arteritis

Answer

Polycystic kidney disease

Question 10

A female has a diastolic blood pressure (DBP) of 100 mm Hg on two consecutive occasions. What is the best initial management?

Accepted Answer

Antihypertensive drugs

Answer

Rest

Answer

Sedation

Answer

Check for error in BP machine

Cardiology — MCQs

Cardiology — MCQs

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