Cardiology Practice Questions

Q: Which one of the following electrocardiographic changes is found in hypercalcemia?

Short Q-T interval. The correct answer is **Short Q-T interval**. **Mechanism:** The QT interval on an ECG represents the total duration of ventricular depolarization and repolarization. In **hypercalcemia**, the increased extracellular calcium concentration shortens the duration of the action potential plateau (Phase 2) by accelerating calcium influx. This leads to faster ventricular repolarization, which manifests on the ECG as a shortened ST segment and, consequently, a **shortened QT interval**. **Analysis of Incorrect Options:** * **A. Prolonged Q-T interval:** This is a classic finding in **hypocalcemia**. Low calcium levels delay Phase 2 of the action potential, lengthening the ST segment. * **C. Increased QRS interval:** Widening of the QRS complex is typically associated with hyperkalemia, bundle branch blocks, or tricyclic antidepressant (TCA) toxicity, rather than calcium imbalances [1]. * **D. Short P-R interval:** A short PR interval is characteristic of pre-excitation syndromes like Wolff-Parkinson-White (WPW) syndrome [2] or Lown-Ganong-Levine (LGL) syndrome [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Osborn Waves (J waves):** While most commonly associated with hypothermia, they can occasionally be seen in severe hypercalcemia. * **Severe Hypercalcemia:** Can lead to T-wave flattening or inversion, and in extreme cases, may mimic an acute myocardial infarction (pseudoinfarction pattern). * **Mnemonic:** "Short Cow (Ca) = Short QT" and "Long Cow (Ca) = Long QT." * **Digoxin Toxicity:** Also causes a shortened QT interval; however, it is distinguished by the characteristic "reverse tick" or "scooped" ST-segment depression.

Q: Which of the following conditions causes a wide pulse pressure?

Aortic regurgitation. **Explanation:** **Pulse pressure** is the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP). A **wide pulse pressure** occurs when there is either an increase in stroke volume or a decrease in peripheral vascular resistance/arterial compliance [1]. **Why Aortic Regurgitation (AR) is the Correct Answer:** In AR, blood flows back from the aorta into the left ventricle during diastole [3]. This leads to: 1. **Increased SBP:** The left ventricle handles an increased stroke volume (normal venous return + regurgitant volume), ejecting more blood into the aorta [1]. 2. **Decreased DBP:** The rapid "runoff" of blood back into the ventricle and into the peripheral circulation causes a significant drop in diastolic pressure. The combination of high SBP and low DBP results in a characteristically wide pulse pressure. **Why Other Options are Incorrect:** * **Aortic Stenosis (AS):** Causes a **narrow pulse pressure** (*pulsus parvus et tardus*). The obstructed outflow reduces stroke volume, leading to a low systolic pressure [2]. * **Mitral Stenosis (MS) & Tricuspid Stenosis (TS):** These conditions limit ventricular filling, which reduces stroke volume and cardiac output, typically resulting in a narrow or normal pulse pressure [4]. **High-Yield Clinical Pearls for NEET-PG:** * **Water-hammer pulse (Corrigan’s pulse):** A rapid upstroke and collapse of the carotid pulse, pathognomonic for AR [1]. * **Traube’s sign:** "Pistol shot" sounds heard over the femoral arteries. * **Duroziez’s sign:** A systolic and diastolic murmur heard over the femoral artery when compressed. * **Other causes of wide pulse pressure:** Thyrotoxicosis, Patent Ductus Arteriosus (PDA), Anemia, Beriberi, and Atherosclerosis (due to stiffened arteries).

Q: Which of the following diastolic sounds may be heard during cardiac auscultation?

S3. **Explanation:** Diastolic sounds occur between S2 and S1 [2]. To identify the correct answer, one must distinguish between sounds occurring during ventricular filling (diastole) versus those occurring during ventricular contraction (systole). **Correct Answer: A. S3** The **Third Heart Sound (S3)**, also known as the ventricular gallop, occurs during the **early rapid filling phase** of diastole [2]. It is caused by blood rushing into an overfilled or dilated ventricle, hitting the ventricular wall. While it can be physiological in children and athletes, in adults, it is a hallmark of **congestive heart failure (CHF)** or volume overload states (e.g., Mitral Regurgitation). **Analysis of Other Options:** * **B. S4:** While S4 occurs at the end of diastole (atrial kick), it is technically a **pre-systolic** sound. In the context of standard NEET-PG classification, S3 is the classic "diastolic sound" associated with filling, whereas S4 is associated with atrial contraction against a stiff ventricle (e.g., LVH). * **C. Opening Snap:** This is a high-pitched diastolic sound heard in **Mitral Stenosis** [1]. However, it is an opening sound of a valve, not a heart sound produced by blood flow/vibration like S3. * **D. Ejection Click:** This is an **early systolic** sound [1]. It occurs shortly after S1 and is associated with the opening of semilunar valves (Aortic/Pulmonary) in conditions like stenosis or bicuspid aortic valve. **High-Yield NEET-PG Pearls:** * **S3 (Ventricular Gallop):** Best heard at the apex with the bell (low pitch). Associated with **systolic dysfunction**. * **S4 (Atrial Gallop):** Associated with **diastolic dysfunction** (stiff ventricle). Absent in Atrial Fibrillation. * **Sequence of Diastolic Sounds:** S2 → Opening Snap → S3 → Mid-diastolic murmur → S4 → S1 [1].

Q: What is the most important drug in the treatment of Ischemic Heart Disease?

Aspirin. **Explanation:** **Aspirin** is considered the most important drug in the management of Ischemic Heart Disease (IHD) because it is the only medication among the options that has been definitively proven to **reduce mortality** across the entire spectrum of the disease—from stable angina to Acute Coronary Syndrome (ACS) [1]. Its mechanism involves the irreversible inhibition of Cyclooxygenase-1 (COX-1), preventing the synthesis of Thromboxane A2 [2]. This inhibits platelet aggregation, thereby preventing the progression of a stable plaque into an occlusive thrombus [2]. **Analysis of Incorrect Options:** * **Statins (Option A):** While crucial for long-term plaque stabilization and secondary prevention (lowering LDL), they do not provide the immediate life-saving anti-thrombotic effect seen with Aspirin during acute events. * **Beta-blockers (Option B):** These are the first-line drugs for **symptom control** in stable angina as they reduce myocardial oxygen demand [3]. While they improve survival post-MI, they are secondary to Aspirin in overall priority. * **Nitrates (Option D):** These are primarily **venodilators** used for symptomatic relief of chest pain [1]. They have **no proven mortality benefit** in IHD. **Clinical Pearls for NEET-PG:** * **Gold Standard Dose:** In acute settings, a loading dose of 150–300 mg (chewed for faster absorption) is recommended. * **Primary vs. Secondary Prevention:** Aspirin is mandatory for secondary prevention; however, its role in primary prevention is now restricted due to bleeding risks. * **Contraindication:** In patients with true Aspirin allergy, **Clopidogrel** is the preferred alternative [1]. * **High-Yield Fact:** Aspirin reduces the risk of MI and death by approximately 25-30% in patients with unstable angina.

Q: Which infective organism is a known cause of atrioventricular block?

Borrelia burgdorferi. The correct answer is **Borrelia burgdorferi**, the causative agent of **Lyme disease**. **1. Why Borrelia burgdorferi is correct:** Lyme carditis occurs in approximately 1–10% of patients during the early disseminated stage of infection [1]. The hallmark of Lyme carditis is **atrioventricular (AV) nodal conduction block**, which can range from first-degree to complete (third-degree) heart block [1]. The organism infiltrates the cardiac conduction system, causing localized inflammation (myocarditis). A classic clinical scenario is a young patient presenting with sudden-onset high-grade AV block, often preceded by erythema migrans or joint pain [1]. **2. Why the other options are incorrect:** * **Treponema pallidum:** Causes Syphilis. While tertiary syphilis can cause cardiovascular complications like **aortitis** and aortic regurgitation (due to vasa vasorum involvement), it typically does not target the AV node directly. * **Cryptococcus:** This is a fungal pathogen primarily causing meningitis or pneumonia in immunocompromised patients; it does not have a predilection for the cardiac conduction system. * **Listeria monocytogenes:** Primarily causes meningitis or sepsis, especially in neonates, the elderly, and the immunocompromised. It is not a recognized cause of heart block. **3. NEET-PG High-Yield Pearls:** * **Lyme Carditis Management:** Most AV blocks in Lyme disease are reversible with appropriate antibiotic therapy (IV Ceftriaxone or oral Doxycycline) [3]. Permanent pacemakers are rarely required [4]. * **Other Infectious Causes of AV Block:** Chagas disease (*Trypanosoma cruzi*), Diphtheria (due to exotoxin), and Viral myocarditis (e.g., Coxsackie B). * **ECG in Lyme:** Look for fluctuating degrees of AV block; it can progress rapidly from 1st degree to 3rd degree [2].

Q: Which of the following findings is NOT seen in primary pulmonary hypertension?

Right parasternal heave. In primary pulmonary hypertension (now classified under Pulmonary Arterial Hypertension), the core pathophysiology involves increased resistance in the pulmonary vasculature, leading to **Right Ventricular (RV) hypertrophy and dilatation.** [1] **Why "Right parasternal heave" is the correct answer (the finding NOT seen):** This is a classic "trick" question regarding bedside physical examination. A heave (precordial lift) caused by right ventricular enlargement is felt at the **Left Parasternal** border (3rd/4th intercostal space) [3]. There is no such clinical entity as a "Right parasternal heave" in the context of pulmonary hypertension; the heart is situated in the left hemithorax, and RV enlargement displaces the impulse toward the left sternal border, not the right. **Analysis of Incorrect Options:** * **Left parasternal heave:** This is a hallmark sign of RV hypertrophy/enlargement, which occurs as the right ventricle pumps against high pulmonary pressures [3]. * **Single S2:** In severe pulmonary hypertension, the pulmonary component (P2) becomes very loud and occurs earlier, often merging with the aortic component (A2), resulting in a single, loud S2 [1]. * **Pulmonary ejection click:** This is caused by the sudden opening of the pulmonary valve into a dilated pulmonary artery under high pressure. It is typically heard at the left upper sternal border. **High-Yield Clinical Pearls for NEET-PG:** * **P2 Intensity:** A loud P2 (palpable in the 2nd left intercostal space) is the most sensitive physical sign of pulmonary hypertension [3]. * **Graham Steell Murmur:** A high-pitched, decrescendo diastolic murmur of pulmonary regurgitation may be heard. * **ECG Findings:** Look for "P pulmonale" (tall, peaked P waves) and Right Axis Deviation [2].

Q: What is the best treatment for multifocal atrial tachycardia?

Verapamil. **Explanation:** Multifocal Atrial Tachycardia (MAT) is a supraventricular arrhythmia characterized by a heart rate >100 bpm and at least three distinct P-wave morphologies in the same lead. It is most commonly associated with underlying pulmonary diseases, particularly **COPD** or acute respiratory failure. **Why Verapamil is the correct answer:** The primary management of MAT is treating the underlying cause (e.g., correcting hypoxia or hypercapnia). However, when pharmacological rate control is required, **Calcium Channel Blockers (Verapamil or Diltiazem)** are the drugs of choice [1]. Verapamil works by slowing conduction through the AV node and suppressing the ectopic atrial foci. **Why other options are incorrect:** * **DC Shock (A):** MAT is an irregular rhythm arising from multiple foci, not a re-entrant circuit. Therefore, electrical cardioversion is ineffective and contraindicated. * **Amiodarone (B):** While it has anti-arrhythmic properties, it is not the first-line treatment for MAT and carries a higher risk of toxicity compared to CCBs [1]. * **Beta-blockers (D):** Although they can control the rate, they are generally **avoided** because MAT is frequently associated with severe COPD/Asthma, where beta-blockers can precipitate bronchospasm [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnostic Triad:** HR >100 bpm, ≥3 different P-wave shapes, and irregular P-P intervals. * **Wandering Atrial Pacemaker (WAP):** Same ECG findings as MAT but with a heart rate <100 bpm. * **The

Q: All of the following are true regarding hypertrophic obstructive cardiomyopathy, except?

Digitalis is useful. **Explanation:** Hypertrophic Obstructive Cardiomyopathy (HOCM) is characterized by a dynamic pressure gradient in the subaortic region due to septal hypertrophy and systolic anterior motion (SAM) of the mitral valve. **Why Option A is the correct answer (False statement):** **Digitalis (Digoxin)** is a positive inotrope. In HOCM, increasing the force of myocardial contraction worsens the left ventricular outflow tract (LVOT) obstruction by narrowing the outflow tract further during systole. Therefore, Digitalis is **contraindicated** in HOCM (unless there is concomitant atrial fibrillation with a fast ventricular rate). Similarly, diuretics and vasodilators should be used with extreme caution as they decrease preload/afterload, which also worsens the obstruction. **Analysis of other options:** * **B. Left ventricular outflow obstruction:** This is the hallmark of HOCM, caused by the hypertrophied septum and the SAM of the mitral valve [1]. * **C. Asymmetrical septal thickness:** HOCM typically involves disproportionate thickening of the interventricular septum compared to the posterior wall (Septum:Free wall ratio > 1.3:1) [1]. * **D. Double apical impulse:** Patients often exhibit a "double" or "triple" apical impulse. The double impulse is due to a forceful atrial contraction (S4) followed by the sustained ventricular apex beat [1]. **NEET-PG High-Yield Pearls:** * **Management:** Beta-blockers are the first-line treatment (they increase diastolic filling time and decrease contractility). Calcium channel blockers (Verapamil) are also used. * **Murmur Dynamics:** The systolic murmur of HOCM **increases** with Valsalva and standing (decreased preload) and **decreases** with squatting and handgrip (increased preload/afterload). * **Jerky Pulse:** Often described as *Pulsus Bisferiens*.

Question 1

All of the following may be seen in ventricular premature beats, EXCEPT?

Accepted Answer

Narrow QRS complex

Answer

Fusion beat

Answer

AV Dissociation

Answer

Wide QRS complex

Question 2

Which one of the following electrocardiographic changes is found in hypercalcemia?

Accepted Answer

Short Q-T interval

Answer

Prolonged Q-T interval

Answer

Increased QRS interval

Answer

Short P-R interval

Question 3

Which of the following conditions causes a wide pulse pressure?

Accepted Answer

Aortic regurgitation

Answer

Aortic stenosis

Answer

Mitral stenosis

Answer

Tricuspid stenosis

Question 4

An 18-year-old man is admitted to the hospital with acute onset of substernal chest pain that began abruptly 30 minutes ago. The pain radiates to his neck and right arm. He has otherwise been in good health. On physical examination, he is diaphoretic and tachypnoeic. His BP is 102/48 mmHg and heart rate is 112 bpm, with a regular rhythm but is tachycardiac. A 2/6 holosystolic murmur is heard best at the apex and radiates to the axilla. His lungs have bilateral rales at the bases. The ECG demonstrates 4 mm of ST elevation in the anterior leads. In the past, he was hospitalized for some problem with his heart when he was 4 years old. His mother, who accompanies him, reports that he received aspirin and gamma globulin as treatment. Since that time, he has required intermittent follow-up with echocardiography. What is the most likely cause of this patient's acute coronary syndrome?

Accepted Answer

Thrombosis of a coronary artery aneurysm

Answer

Dissection of the aortic root and left coronary ostia

Answer

Presence of a myocardial bridge overlying the left anterior descending artery

Answer

Vasospasm following cocaine ingestion

Question 5

Which of the following diastolic sounds may be heard during cardiac auscultation?

Accepted Answer

S3

Answer

S4

Answer

Opening snap

Answer

Ejection click

Question 6

What is the most important drug in the treatment of Ischemic Heart Disease?

Accepted Answer

Aspirin

Answer

Statins

Answer

Beta blockers

Answer

Nitrates

Question 7

Which infective organism is a known cause of atrioventricular block?

Accepted Answer

Borrelia burgdorferi

Answer

Treponema pallidum

Answer

Cryptococcus

Answer

Listeria monocytogenes

Question 8

Which of the following findings is NOT seen in primary pulmonary hypertension?

Accepted Answer

Right parasternal heave

Answer

Left parasternal heave

Answer

Single S2

Answer

Pulmonary ejection click

Question 9

What is the best treatment for multifocal atrial tachycardia?

Accepted Answer

Verapamil

Answer

DC shock

Answer

Amiodarone

Answer

Beta blocker

Question 10

All of the following are true regarding hypertrophic obstructive cardiomyopathy, except?

Accepted Answer

Digitalis is useful

Answer

Left ventricular outflow obstruction

Answer

Asymmetrical septal thickness

Answer

Double apical impulse

Cardiology — MCQs

Cardiology — MCQs

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