Cardiology Practice Questions

Q: What is the drug of choice for persistent unstable ventricular arrhythmia?

Amiodarone. **Explanation:** **Amiodarone** is the drug of choice for persistent unstable ventricular arrhythmias (such as Ventricular Tachycardia or Ventricular Fibrillation) that are refractory to electrical cardioversion or defibrillation. As a Class III antiarrhythmic, its primary mechanism is blocking potassium channels, which prolongs the action potential duration and effective refractory period. However, it also possesses Class I (sodium channel), Class II (beta-blocking), and Class IV (calcium channel) properties, making it highly effective across various myocardial tissues. **Why other options are incorrect:** * **Procainamide (Option A):** While a Class IA antiarrhythmic used for stable VT (especially in Wolff-Parkinson-White syndrome), it is not the first-line choice for persistent unstable arrhythmias due to its slower onset and risk of hypotension. * **Calcium Gluconate (Option B):** This is used for cardioprotection in hyperkalemia or for calcium channel blocker toxicity; it has no direct antiarrhythmic effect on ventricular tachycardia. * **Digoxin (Option C):** Used primarily for rate control in atrial fibrillation or in heart failure. It can actually *induce* ventricular arrhythmias in toxic doses. **NEET-PG High-Yield Pearls:** * **ACLS Protocol:** In pulseless VT/VF, Amiodarone is administered after the third shock. Lidocaine is the alternative if Amiodarone is unavailable. * **Side Effects:** Long-term use is associated with "6 Ps": **P**ulmonary fibrosis, **P**hotodermatitis (Blue-grey skin), **P**rolonged QT, **P**eripheral neuropathy, and **P**eripapillary (corneal) deposits, and Thyroid **P**athology (Hypo/Hyperthyroidism due to high iodine content). * **Drug of Choice:** Amiodarone is also the drug of choice for arrhythmias in patients with structural heart disease or decreased ejection fraction.

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**.

Q: A 72-year-old male presented to the ER with falls. Based on the provided ECG interpretation, what is the likely diagnosis?

Second-degree heart block, Mobitz Type 1. ***Second-degree heart block, Mobitz Type 1*** - Characterized by **progressive PR interval prolongation** until a **QRS complex is dropped**, followed by **reset of the cycle** (Wenckebach phenomenon). - Falls in elderly patients occur due to **intermittent bradycardia** and **transient hemodynamic compromise** from dropped beats. *Hyperkalemia* - ECG shows **peaked T waves**, **widened QRS complexes**, and eventually **sine wave pattern** in severe cases. - Does not typically cause **progressive PR prolongation** with **dropped beats** as seen in this scenario. *Second-degree heart block, Mobitz Type 2* - Features **constant PR intervals** with **sudden dropping** of QRS complexes without prior prolongation. - More dangerous than Type 1 as it can **progress to complete heart block** and requires **immediate pacing**. *First-degree heart block* - Shows **prolonged PR interval** (>200ms) but **all P waves are conducted** to the ventricles. - Does not involve **dropped QRS complexes** and typically does not cause falls or hemodynamic instability.

Q: What is the characteristic cardiac anomaly associated with Lutembacher syndrome?

Ventricular septal defect. Lutembacher Syndrome is a specific clinical entity defined by the combination of acquired Mitral Stenosis (MS) [2] and a congenital Atrial Septal Defect (ASD) [4]. **Why the provided answer (C) is technically incorrect based on standard medical definitions:** In standard medical literature, Lutembacher syndrome consists of Mitral Stenosis + Atrial Septal Defect. If the question identifies Ventricular Septal Defect (VSD) as the "correct" answer, it likely represents a common error in specific question banks or a mislabeled option. Classically, a VSD is *not* a component of Lutembacher syndrome [1], [3]. **Analysis of Options:** * **A & B (Mitral Stenosis & Atrial Septal Defect):** These are the two classic components. The ASD (usually ostium secundum) provides a "decompression" route for the high left atrial pressure caused by MS, leading to an early and severe left-to-right shunt [4]. * **C (Ventricular Septal Defect):** This is traditionally incorrect. However, if forced to choose in a flawed question paper, ensure you recall the classic MS + ASD triad. * **D (Left to Right Shunt):** This is a *hemodynamic consequence* of the syndrome, not the anatomical anomaly itself. **NEET-PG High-Yield Pearls:** 1. **Hemodynamics:** The ASD protects the lungs from pulmonary congestion initially by shunting blood from the LA to the RA, but this leads to early **Right Ventricular Failure** and pulmonary hypertension [2]. 2. **Clinical Sign:** The typical diastolic murmur of MS (mid-diastolic rumble) is often **diminished or absent** because the ASD reduces the pressure gradient across the mitral valve [2]. 3. **Graham Steell Murmur:** May be present due to secondary pulmonary regurgitation from pulmonary hypertension. 4. **Treatment:** Percutaneous management (Balloon Mitral Valvotomy + Device closure of ASD) is now the preferred approach.

Q: Pulsus paradoxus is seen in which of the following conditions?

Emphysema. **Explanation:** **Pulsus paradoxus** is defined as an exaggerated decrease in systolic blood pressure (>10 mmHg) during inspiration. While most commonly associated with cardiac tamponade, it is also a classic finding in severe obstructive airway diseases like **Emphysema** and Asthma. **Why Emphysema is correct:** In Emphysema, hyperinflation of the lungs and increased airway resistance lead to extreme fluctuations in intrathoracic pressure. During inspiration, the highly negative intrathoracic pressure increases venous return to the right heart, causing the interventricular septum to bulge into the left ventricle (Bernheim effect). Simultaneously, the negative pressure "pools" blood in the expanded pulmonary vasculature, reducing left ventricular filling and stroke volume, thus dropping the systolic BP. **Why the other options are incorrect:** * **Infective Endocarditis:** Typically presents with murmurs, fever, and embolic phenomena (Janeway lesions, Osler nodes), but does not affect intrathoracic pressure dynamics to cause pulsus paradoxus. * **Mitral Stenosis:** Characterized by a mid-diastolic murmur and opening snap. It does not typically cause pulsus paradoxus; in fact, it may be associated with *pulsus parvus* (small volume pulse). * **Hypertrophic Cardiomyopathy (HCM):** Classically associated with **Pulsus Bisferiens** (a double-peaked systolic pulse). **High-Yield Clinical Pearls for NEET-PG:** * **Kussmaul’s Sign vs. Pulsus Paradoxus:** Kussmaul’s sign (rise in JVP on inspiration) is seen in Constrictive Pericarditis, whereas Pulsus Paradoxus is the hallmark of Cardiac Tamponade. * **Reverse Pulsus Paradoxus:** Seen in Hypertrophic Obstructive Cardiomyopathy (HOCM) and during positive pressure ventilation. * **Conditions with Pulsus Paradoxus:** Cardiac tamponade, Severe Asthma/COPD, Constrictive pericarditis (only in ~30%), and Massive Pulmonary Embolism.

Q: Which of the following is seen in torsades de pointes?

Prolonged QTc interval. **Explanation:** **Torsades de Pointes (TdP)** is a specific form of polymorphic ventricular tachycardia characterized by a "twisting of the points" around the isoelectric line [1]. 1. **Why Option C is correct:** The hallmark physiological prerequisite for TdP is a **prolonged QTc interval** [1]. Prolongation of the QT interval reflects delayed ventricular repolarization (usually due to blockade of potassium channels). This delay allows for "Early After-Depolarizations" (EADs), which can trigger a run of ventricular tachycardia. In clinical practice, a QTc > 500 ms is considered a high-risk zone for developing TdP. 2. **Why other options are incorrect:** * **Option A:** TdP is associated with **Hypomagnesemia**, not hypermagnesemia. Magnesium is the treatment of choice because it stabilizes the cardiac membrane. * **Option B:** TdP is a ventricular rhythm, which by definition involves a **wide QRS complex** (polymorphic), not a short one. * **Option D:** The PQ segment (part of the PR interval) relates to AV nodal conduction and is not the primary diagnostic feature of TdP. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Can be congenital (Jervell and Lange-Nielsen, Romano-Ward syndromes) or acquired (Drugs like Class IA/III antiarrhythmics, Macrolides, Antipsychotics, or electrolyte imbalances like Hypokalemia/Hypomagnesemia). * **Drug of Choice:** **Intravenous Magnesium Sulfate** is the first-line treatment, even if serum magnesium levels are normal. * **ECG Feature:** Look for the characteristic "spindle-node" pattern where the QRS axis rotates 180° over 5–20 beats [1].

Question 1

What is the drug of choice for persistent unstable ventricular arrhythmia?

Accepted Answer

Amiodarone

Answer

Procainamide

Answer

Calcium gluconate

Answer

Digoxin

Question 2

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 3

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 4

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 5

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

Question 6

What is the metabolic defect in accelerated hypertension?

Accepted Answer

Metabolic alkalosis

Answer

Normal non-ionic metabolic acidosis

Answer

Ionic gap metabolic acidosis

Answer

Hypomagnesemia

Question 7

A 72-year-old male presented to the ER with falls. Based on the provided ECG interpretation, what is the likely diagnosis?

Accepted Answer

Second-degree heart block, Mobitz Type 1

Answer

Hyperkalemia

Answer

Second-degree heart block, Mobitz Type 2

Answer

First-degree heart block

Question 8

What is the characteristic cardiac anomaly associated with Lutembacher syndrome?

Accepted Answer

Ventricular septal defect

Answer

Mitral stenosis

Answer

Atrial septal defect

Answer

Left to right shunt

Question 9

Pulsus paradoxus is seen in which of the following conditions?

Accepted Answer

Emphysema

Answer

Infective endocarditis

Answer

Mitral stenosis

Answer

Hypertrophic cardiomyopathy

Question 10

Which of the following is seen in torsades de pointes?

Accepted Answer

Prolonged QTc interval

Answer

Hypermagnesemia

Answer

Short QRS complex

Answer

PQ segment

Cardiology — MCQs

Cardiology — MCQs

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