Cardiology Practice Questions

Q: Sudden death can be due to which of the following conditions?

Ventricular fibrillation. Explanation: **Sudden Cardiac Death (SCD)** is defined as a natural, unexpected death due to cardiac causes, usually occurring within one hour of the onset of symptoms. **1. Why Ventricular Fibrillation (VF) is correct:** Ventricular fibrillation is the most common terminal rhythm identified in cases of sudden cardiac arrest [3]. In VF, the ventricles lose their coordinated contraction and instead "quiver" chaotically [2]. This results in an immediate loss of cardiac output, leading to cessation of cerebral blood flow and death within minutes unless immediate defibrillation is performed [1]. It is frequently triggered by acute myocardial ischemia or underlying structural heart disease. **2. Analysis of Incorrect Options:** * **QT Prolongation:** While a prolonged QT interval (Congenital or Acquired) is a significant *risk factor* for SCD because it can lead to Torsade de Pointes, it is the resulting arrhythmia (VF or VT), not the prolongation itself, that causes death [1]. * **Atrial Flutter:** This is a supraventricular tachycardia. While it can cause palpitations or hemodynamic compromise in patients with poor ventricular function, it is rarely life-threatening as the AV node protects the ventricles from the high atrial rate. * **Ventricular Premature Contractions (VPCs):** These are common, often benign ectopic beats. While frequent VPCs can be markers of underlying heart disease, they do not cause sudden death in isolation. **Clinical Pearls for NEET-PG:** * **Most common cause of SCD:** Coronary Artery Disease (CAD) is responsible for ~80% of cases. * **Hypertrophic Cardiomyopathy (HCM):** The most common cause of SCD in young athletes. * **The "Golden Hour":** Survival rates for VF decrease by 7-10% for every minute that passes without defibrillation [3]. * **Commotio Cordis:** Sudden death caused by a blunt, non-penetrating blow to the chest during the vulnerable phase of ventricular repolarization [2].

Q: What is the most common heart valve involved in intravenous drug users?

Tricuspid valve. Explanation: In the context of Infective Endocarditis (IE), the choice of valve involvement is heavily influenced by the route of entry of the pathogen. Why the Tricuspid Valve is Correct: Intravenous drug use (IVDU) involves the direct introduction of pathogens (most commonly *Staphylococcus aureus*) into the venous circulation [1]. These pathogens travel through the superior or inferior vena cava directly into the right side of the heart. The **Tricuspid Valve** is the first cardiac valve they encounter. Approximately 60–70% of IE cases in IVDU involve the tricuspid valve. Analysis of Incorrect Options: * **Mitral Valve (A):** This is the most common valve involved in the **general population** (non-IVDU) and in patients with underlying rheumatic heart disease. In IVDUs, left-sided involvement can occur but is less frequent than right-sided involvement. * **Aortic Valve (B):** This is the second most common valve involved in the general population. While it can be affected in IVDUs (often concurrently with the mitral valve), it is not the *most* common. * **Pulmonary Valve (C):** This is the least commonly involved valve in both IVDUs and the general population. High-Yield Clinical Pearls for NEET-PG: * **Most Common Organism (IVDU):** *Staphylococcus aureus* (often MRSA) [1]. * **Septic Emboli:** Right-sided endocarditis (Tricuspid) frequently presents with **septic pulmonary emboli**, leading to cough, chest pain, and "flea-bitten" lung appearance on imaging. * **Classic Triad:** Fever, anemia, and a new murmur (though murmurs are often absent in early right-sided IE). * **Culture-Negative IE:** Most commonly due to prior antibiotic use or HACEK group organisms. * **Treatment:** IVDU-associated tricuspid IE is often managed medically with antibiotics (e.g., Nafcillin/Vancomycin + Gentamicin); surgery is reserved for refractory cases.

Q: Kussmaul's sign is most commonly seen in which of the following conditions?

Constrictive pericarditis. **Explanation:** **Kussmaul’s sign** is defined as a paradoxical rise (or lack of fall) in the Jugular Venous Pressure (JVP) during inspiration. Normally, JVP falls during inspiration because the negative intrathoracic pressure increases venous return to the right heart. **1. Why Constrictive Pericarditis is the Correct Answer:** In **Constrictive Pericarditis**, the heart is encased in a rigid, non-compliant pericardium [1]. During inspiration, the increased venous return cannot be accommodated by the right ventricle because it cannot expand outward. This leads to a backup of pressure into the vena cava and jugular veins, causing the JVP to rise. While it is also seen in Restrictive Cardiomyopathy, it is a **classic hallmark** and most frequently associated with Constrictive Pericarditis in exam scenarios. **2. Analysis of Incorrect Options:** * **Pericardial Tamponade:** This is the most important distractor [1]. Kussmaul’s sign is **absent** in tamponade because the intrapericardial pressure is fluid-based and can still transmit negative intrathoracic pressure changes. Instead, tamponade is characterized by **Pulsus Paradoxus**. * **Restrictive Cardiomyopathy:** While Kussmaul’s sign can occur here, it is less common than in constriction. * **Right Ventricular Infarct:** It can be seen here due to RV failure, but it is a transient finding compared to the chronic presentation of pericardial disease [2]. **3. NEET-PG High-Yield Pearls:** * **Kussmaul’s Sign vs. Pulsus Paradoxus:** Remember, Kussmaul’s sign is seen in Constriction (not Tamponade), while Pulsus Paradoxus is seen in Tamponade (not Constriction). * **Other causes of Kussmaul’s sign:** Right Ventricular Infarction, Tricuspid Stenosis, and Right-sided Heart Failure. * **JVP Waveform:** In Constrictive Pericarditis, look for prominent **'y' descents** (Friedreich’s sign).

Q: Which of the following conditions is associated with a "pea soup" or "head bag" appearance on abdominal X-ray?

Hypermagnesemia. **Explanation:** **Hypermagnesemia** is the correct answer. The "pea soup" or "head bag" appearance on an abdominal X-ray refers to the presence of diffuse, amorphous, granular opacities within the bowel lumen. This occurs due to the precipitation of magnesium salts (often from magnesium-containing laxatives or antacids) in the gastrointestinal tract. Magnesium is a potent neuromuscular depressant; high levels lead to decreased smooth muscle contractility, resulting in paralytic ileus [1]. This stasis allows the magnesium salts to concentrate and become radiopaque, creating the characteristic mottled appearance. **Incorrect Options:** * **Hypomagnesemia:** Low magnesium levels typically present with neuromuscular irritability (tetany, seizures) and arrhythmias (Torsades de Pointes), but do not produce radiopaque findings on X-ray. * **Hypernatremia:** Primarily affects the central nervous system (altered mental status, brain shrinkage) due to osmotic shifts; it has no specific pathognomonic radiological sign in the abdomen. * **Hypocalcemia:** While it causes neuromuscular excitability (Chvostek’s and Trousseau’s signs) and QT prolongation, it does not result in the "pea soup" appearance. **Clinical Pearls for NEET-PG:** * **Magnesium and the Gut:** Magnesium acts as an osmotic laxative. In renal failure patients, excessive intake can lead to toxicity. * **Antidote:** The immediate treatment for severe hypermagnesemia (with respiratory depression or cardiac conduction defects) is **Intravenous Calcium Gluconate**, which antagonizes the membrane effects of magnesium. * **Reflexes:** Loss of deep tendon reflexes (DTRs) is the earliest clinical sign of hypermagnesemia (occurring at 4–6 mEq/L).

Q: A 48-year-old male presents with a history of precordial chest pain. His blood pressure is 80/60 mm Hg. An ECG shows a wide QRS complex with no preceding P waves and a rate of 112/min. What is the most immediate step in the management of this patient?

Direct current electrical cardioversion. The patient presents with **Ventricular Tachycardia (VT)**, characterized by a wide QRS complex, absence of P waves, and a rate >100/min [1]. The most critical factor in this clinical scenario is the patient’s **hemodynamic instability**, evidenced by a blood pressure of 80/60 mm Hg (hypotension) and precordial chest pain. **1. Why Option B is Correct:** According to ACLS guidelines, any tachyarrhythmia (wide or narrow complex) associated with **hemodynamic instability** (hypotension, altered mental status, signs of shock, ischemic chest pain, or acute heart failure) must be treated with **immediate synchronized Direct Current (DC) Cardioversion** [1]. In an unstable patient, pharmacological interventions are bypassed to prevent progression to ventricular fibrillation or cardiac arrest [2]. **2. Why Other Options are Incorrect:** * **Option A (IV Lidocaine):** While lidocaine is an antiarrhythmic used for VT, it is indicated only in **hemodynamically stable** patients. In this unstable patient, waiting for drug infusion is contraindicated. * **Option C (Overdrive Atrial Pacing):** This is typically used for refractory Torsades de Pointes or specific supraventricular tachycardias; it is not the first-line treatment for unstable VT. * **Option D (Primary PTCA):** While the patient has chest pain suggesting ischemia, the immediate life-threatening issue is the arrhythmia causing low cardiac output. Hemodynamic stabilization via cardioversion must precede any coronary intervention. **Clinical Pearls for NEET-PG:** * **Stable VT:** Treat with IV Amiodarone (preferred), Procainamide, or Lidocaine. * **Unstable VT (with pulse):** Synchronized DC Cardioversion [1]. * **Pulseless VT/VF:** Defibrillation (Unsynchronized shock) [2]. * **Rule of Thumb:** "If they are unstable and have a pulse, you shock (sync); if they have no pulse, you shock (unsync)."

Q: Which of the following is NOT associated with prolonged QT syndrome?

Lidocaine therapy. The correct answer is **Lidocaine therapy**. ### **Explanation** Prolonged QT syndrome (LQTS) results from delayed repolarization of the myocardium, typically due to the inhibition of potassium efflux or the enhancement of sodium influx. [1] **Why Lidocaine is the correct answer:** Lidocaine is a **Class IB antiarrhythmic**. Unlike Class IA or Class III agents, Class IB drugs **shorten** the action potential duration and the QT interval. Because it does not prolong repolarization, it is not associated with Long QT Syndrome or the risk of Torsades de Pointes (TdP). **Analysis of Incorrect Options:** * **Romano-Ward Syndrome:** The most common **autosomal dominant** congenital LQTS. It involves pure cardiac manifestations (prolonged QT) without deafness. * **Jervell and Lange-Nielsen Syndrome:** An **autosomal recessive** congenital LQTS. It is characterized by a very long QT interval and is uniquely associated with **sensorineural deafness**. [1] * **Encainide Therapy:** Encainide is a **Class IC antiarrhythmic**. While Class IC drugs primarily affect the QRS duration (sodium channel blockade), they can also cause modest prolongation of the QT interval in some patients, though less significantly than Class IA (e.g., Procainamide) or Class III (e.g., Amiodarone, Sotalol). [2] ### **High-Yield Clinical Pearls for NEET-PG** * **Drug-Induced LQTS Mnemonic (ABCDE):** **A**ntiarrhythmics (Class IA, III), **B**iotics (Macrolides, Quinolones), **C**isapride/Antipsychotics (Haloperidol), **D**epressants (TCAs), **E**metics (Ondansetron). * **Electrolyte triggers:** Hypokalemia, Hypomagnesemia, and Hypocalcemia all prolong the QT interval. [3] * **Management:** Congenital LQTS is primarily treated with **Beta-blockers** (Propranolol/Nadolol). Acute Torsades de Pointes is treated with **IV Magnesium Sulfate**.

Question 1

A 47-year-old woman presents with accelerated hypertension (blood pressure 210/105 mm Hg) and frequent headaches for the past month. She has a past medical history notable for hypertension during her first pregnancy, and her family history is positive for hypertension in both parents and a brother. On physical examination, her blood pressure is 210/105 mm Hg in both arms, heart rate is 88/min, and she is alert and oriented. Cardiac examination reveals an S4, lungs are clear, and there are no focal neurological deficits. Which of the following findings are most likely on examination of the fundi?

Accepted Answer

Cotton wool spots

Answer

Retinitis obliterans

Answer

Retinal detachment

Answer

Optic atrophy

Question 2

What is the most common cause of mitral stenosis?

Accepted Answer

Rheumatic heart disease

Answer

Infective endocarditis

Answer

Diabetes mellitus

Answer

Congenital

Question 3

Sudden death can be due to which of the following conditions?

Accepted Answer

Ventricular fibrillation

Answer

QT prolongation

Answer

Atrial flutter

Answer

Ventricular premature contractions (VPCs)

Question 4

What is the most common heart valve involved in intravenous drug users?

Accepted Answer

Tricuspid valve

Answer

Mitral valve

Answer

Aortic valve

Answer

Pulmonary valve

Question 5

Pseudo resistant hypertension is seen in which situation?

Accepted Answer

Patient at the office

Answer

Patient at home

Answer

Patient at the hospital

Answer

None of the above

Question 6

Kussmaul's sign is most commonly seen in which of the following conditions?

Accepted Answer

Constrictive pericarditis

Answer

Restrictive cardiomyopathy

Answer

Pericardial tamponade

Answer

Right ventricular infarct

Question 7

Which of the following conditions is associated with a "pea soup" or "head bag" appearance on abdominal X-ray?

Accepted Answer

Hypermagnesemia

Answer

Hypomagnesemia

Answer

Hypernatremia

Answer

Hypocalcemia

Question 8

A 48-year-old male presents with a history of precordial chest pain. His blood pressure is 80/60 mm Hg. An ECG shows a wide QRS complex with no preceding P waves and a rate of 112/min. What is the most immediate step in the management of this patient?

Accepted Answer

Direct current electrical cardioversion

Answer

Intravenous lidocaine

Answer

Overdrive atrial pacing

Answer

Primary percutaneous transluminal angioplasty

Question 9

A 65-year-old man presents with dyspnea, chest pain, and several syncopal episodes. His symptoms have worsened over the past few months, and his third syncopal episode prompted this visit. On examination, a systolic ejection murmur with an ejection click is auscultated in the right second intercostal space. Rales are present at the lung bases. He has a history of rheumatic fever in his twenties. Which of the following might explain the angina pectoris in this patient?

Accepted Answer

Increased ventricular wall tension limits perfusion.

Answer

Left ventricular hypertrophy accelerates atherosclerotic disease.

Answer

Pulmonary hypertension decreases the PO2 of arterial blood.

Answer

Stenotic valves occlude the coronary arteries.

Question 10

Which of the following is NOT associated with prolonged QT syndrome?

Accepted Answer

Lidocaine therapy

Answer

Romano-Ward syndrome

Answer

Jervell and Lange-Nielsen syndrome

Answer

Encainide therapy

Cardiology — MCQs

Cardiology — MCQs

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