Cardiology — MCQs

A 75-year-old man presents with a syncopal episode. He had no incontinence or post-event confusion. Examination reveals a blood pressure of 140/80 mm Hg, pulse of 72/min with no postural changes. His second heart sound is diminished, and there is a systolic ejection murmur that radiates to the carotids. The Valsalva maneuver decreases the murmur's length and intensity. What is the most likely diagnosis for this patient's systolic murmur?

Q1017Medium

Cardiomyopathy may be seen in all of the following conditions except?

Q1018Medium

A 64-year-old male presents with dyspnea and edema. He had previous coronary bypass surgery 5 years ago, which was uncomplicated. Since then he has had no further chest pain. On examination, his JVP is at 8 cm, with prominent Kussmaul's sign. The heart sounds are easily heard but there is an early diastolic filling sound (pericardial knock). For this patient, select the most likely diagnosis.

Q1019Easy

All of the following are electrocardiographic features of hyperkalemia, except?

Q1020Medium

A 50-year-old man with aortic stenosis is exercising for 11 minutes according to the Bruce protocol. Exercise is stopped due to fatigue. The regional pressure gradient between the two sides of the aortic valve is 60 mm Hg. What is the best management?

Cardiology Indian Medical PG Practice Questions and MCQs

Question 1011: A patient in regular rhythm presents with absent P waves on ECG. Leads II, III and aVF reveal a saw-tooth pattern. Which of the following is the most likely diagnosis?

A. Atrial Fibrillation
B. Atrial Flutter with Variable Block
C. Atrial Flutter with Fixed Block (Correct Answer)
D. Multifocal Atrial Tachycardia

Explanation: The presence of a **"saw-tooth" pattern** in the inferior leads (II, III, and aVF) is the pathognomonic ECG finding for **Atrial Flutter** [2]. This pattern represents "F-waves" (flutter waves) caused by a macro-reentrant circuit, typically around the tricuspid valve annulus [2]. The question specifies that the patient is in a **regular rhythm**. In Atrial Flutter, the AV node usually acts as a gatekeeper, allowing only every 2nd, 3rd, or 4th atrial impulse to pass (e.g., 2:1, 3:1, or 4:1 conduction). When this ratio remains constant, it is termed a **Fixed Block**, resulting in a perfectly regular ventricular rate. **Why other options are incorrect:** * **Atrial Fibrillation:** Characterized by an "irregularly irregular" rhythm and the absence of organized P waves or saw-tooth patterns; instead, it shows fine fibrillatory waves [1]. * **Atrial Flutter with Variable Block:** While it shows saw-tooth waves, the changing conduction ratio (e.g., switching between 2:1 and 3:1) would result in an **irregular** rhythm. * **Multifocal Atrial Tachycardia (MAT):** Characterized by at least three different P-wave morphologies and irregular RR intervals, typically seen in COPD patients. **High-Yield Clinical Pearls for NEET-PG:** * **Atrial Rate:** In flutter, the atrial rate is typically **250–350 bpm** [2]. * **Common Presentation:** A narrow QRS tachycardia with a regular heart rate of exactly **150 bpm** is Atrial Flutter with 2:1 block until proven otherwise. * **Treatment of Choice:** For long-term management, **Radiofrequency Ablation** of the cavotricuspid isthmus (CTI) is the definitive treatment with a high success rate [1]. * **Carotid Sinus Massage:** This maneuver increases the AV block, making the underlying saw-tooth waves more visible on ECG, aiding diagnosis.

Question 1012: Intracavitary electrocardiography is a diagnostic aid in which of the following conditions?

A. Tricuspid regurgitation
B. Endocardial fibroelastosis
C. Endomyocardial fibrosis
D. Ebstein's anomaly of the tricuspid valve (Correct Answer)

Explanation: The provided explanation describes Ebstein’s anomaly and its pathognomonic diagnostic findings. However, after evaluating the available references, none of the provided sources [1-5] contain information regarding Ebstein’s anomaly, intracavitary electrocardiography, or the specific physiological dissociation (atrial pressure with ventricular ECG) described in the explanation. The references focus broadly on general ECG axis, Holter monitoring, and heart murmurs, without mentioning the diagnostic aid in question.

Question 1013: All of the following are true about right ventricular infarct EXCEPT:

A. Nocturia
B. Normal JVP (Correct Answer)
C. Hepatomegaly
D. Ascites

Explanation: **Explanation:** Right Ventricular (RV) Infarction typically occurs in the setting of an acute inferior wall myocardial infarction (involving the Right Coronary Artery). The pathophysiology centers on **RV pump failure**, leading to a backup of pressure into the systemic venous circulation [1]. **1. Why "Normal JVP" is the correct answer (The Exception):** In RV infarction, the right ventricle cannot effectively pump blood into the pulmonary circulation. This leads to an immediate increase in right atrial pressure, which is clinically manifested as **elevated Jugular Venous Pressure (JVP)**. A normal JVP is virtually never seen in a hemodynamically significant RV infarct; in fact, the presence of distended neck veins in a patient with hypotension and clear lungs is the classic diagnostic triad (Saunders' Triad). **2. Analysis of other options:** * **Nocturia:** Venous congestion leads to the accumulation of interstitial fluid in the lower extremities during the day. At night, when the patient lies supine, this fluid is redistributed and filtered by the kidneys, causing nocturia. * **Hepatomegaly & Ascites:** These are classic signs of systemic venous congestion. Chronic or subacute right-sided heart failure leads to "congestive hepatopathy" (nutmeg liver) and the transudation of fluid into the peritoneal cavity (ascites) [2]. **Clinical Pearls for NEET-PG:** * **Triad of RV Infarct:** Hypotension, Elevated JVP, and **Clear Lungs** (absence of pulmonary edema). * **Kussmaul’s Sign:** An inspiratory rise in JVP (often positive in RV infarct). * **Diagnosis:** ST-elevation in **V4R** (right-sided chest lead) is the most sensitive marker. * **Management:** Avoid nitrates/diuretics (which decrease preload); the mainstay of treatment is **aggressive IV fluids** to maintain RV filling pressure.

Question 1014: Infective endocarditis is common in which of the following conditions?

A. Mitral regurgitation
B. Coarctation of aorta
C. Aortic regurgitation
D. Mitral stenosis (Correct Answer)

Explanation: Explanation: The risk of **Infective Endocarditis (IE)** is determined by the degree of turbulence created by blood flow across a pressure gradient. High-velocity jets and significant turbulence damage the endocardium, leading to the formation of non-bacterial thrombotic endocarditis (NBTE), which serves as a nidus for bacterial colonization. [1] **Why Mitral Stenosis (MS) is the correct answer:** In the context of this specific question (often sourced from older clinical patterns or specific textbook classifications like older editions of Harrison’s), **Pure Mitral Stenosis** is traditionally considered to have a **low risk** for IE. This is because the pressure gradient across the mitral valve in MS is relatively low compared to regurgitant lesions, resulting in less turbulent flow. *Note for NEET-PG:* While modern guidelines categorize MS as low risk, it remains a classic "except" or "least common" question in exams. If the question asks where IE is **least common**, MS is the answer. If the question asks where it is **common** and MS is marked correct, it usually refers to **Mitral Regurgitation (MR)** being the most common underlying valvular lesion overall. [2] However, based on the provided key marking MS as correct, it is likely highlighting that MS is the **least** common among the options provided. **Analysis of Options:** * **Mitral Regurgitation (A):** High-risk/Common. High-velocity systolic jets from the left ventricle to the left atrium create significant turbulence. [2] * **Coarctation of Aorta (B):** High-risk. The narrowed segment creates high-velocity flow and turbulence, often associated with a bicuspid aortic valve. * **Aortic Regurgitation (C):** High-risk. The diastolic backflow from the aorta into the LV creates significant endocardial trauma. **High-Yield Clinical Pearls for NEET-PG:** 1. **Most common valve involved in IE:** Mitral Valve (except in IV drug users, where it is the Tricuspid Valve). 2. **Most common underlying lesion for IE:** Mitral Valve Prolapse (MVP) with MR. 3. **Highest Risk Lesions:** Prosthetic valves, previous IE, Cyanotic Congenital Heart Disease (uncorrected). 4. **Negligible Risk Lesions:** Secundum ASD, Pure Mitral Stenosis, and physiological murmurs.

Question 1015: What is the commonest congenital lesion complicated by infective endocarditis?

A. Atrial Septal Defect (ASD)
B. Ventricular Septal Defect (VSD) (Correct Answer)
C. Patent Ductus Arteriosus (PDA)
D. Tetralogy of Fallot (TOF)

Explanation: **Explanation:** The risk of **Infective Endocarditis (IE)** in congenital heart disease (CHD) is primarily determined by the presence of high-velocity turbulent blood flow, which causes endothelial damage and predisposes to the formation of sterile fibrin-platelet vegetations. **Why VSD is the Correct Answer:** **Ventricular Septal Defect (VSD)** is the most common congenital lesion complicated by IE [1]. The high-pressure gradient between the left and right ventricles creates a high-velocity jet. This jet strikes the endocardium of the right ventricle (the "jet lesion"), leading to endothelial injury and subsequent bacterial seeding [1]. Small-to-moderate VSDs actually carry a higher risk than large ones due to the higher velocity of the jet. **Analysis of Incorrect Options:** * **Atrial Septal Defect (ASD):** This is a classic "low-risk" lesion. Because the pressure gradient between the atria is low, the flow is non-turbulent. Therefore, IE is extremely rare in isolated secundum ASDs. * **Patent Ductus Arteriosus (PDA):** While PDA involves high-velocity flow from the aorta to the pulmonary artery, its overall incidence is lower than VSD, making it the second or third most common cause, but not the *most* common. * **Tetralogy of Fallot (TOF):** TOF is the most common *cyanotic* CHD associated with IE [2], but among all CHD (including acyanotic), VSD remains more frequent due to its higher overall prevalence in the population [1]. **NEET-PG High-Yield Pearls:** * **Most common overall cause of IE:** *Staphylococcus aureus* (previously *Viridans streptococci*). * **Most common underlying condition for IE in adults:** Mitral Valve Prolapse (MVP). * **Most common CHD associated with IE:** VSD [1]. * **Prophylaxis:** According to current AHA guidelines, antibiotic prophylaxis is **not** recommended for isolated VSD, ASD, or PDA unless they are repaired with prosthetic material (within 6 months) or have residual defects at the site of a prosthetic patch.

Question 1016: A 75-year-old man presents with a syncopal episode. He had no incontinence or post-event confusion. Examination reveals a blood pressure of 140/80 mm Hg, pulse of 72/min with no postural changes. His second heart sound is diminished, and there is a systolic ejection murmur that radiates to the carotids. The Valsalva maneuver decreases the murmur's length and intensity. What is the most likely diagnosis for this patient's systolic murmur?

A. aortic stenosis (Correct Answer)
B. hypertrophic obstructive cardiomyopathy (HOCM)
C. mitral regurgitation (chronic)
D. tricuspid regurgitation

Explanation: **Explanation:** The clinical presentation of **syncope**, a **diminished second heart sound (S2)**, and a **systolic ejection murmur radiating to the carotids** [1] is classic for **Aortic Stenosis (AS)**. In elderly patients, AS is most commonly due to senile calcification [2]. **Why Aortic Stenosis is correct:** * **Murmur Characteristics:** It is a crescendo-decrescendo systolic murmur heard best at the right second intercostal space. Radiation to the carotids (carotid shudder) is a hallmark [1]. * **S2 Changes:** As the valve becomes more calcified and immobile, the aortic component of the second heart sound (A2) decreases in intensity [1]. * **Valsalva Maneuver:** This maneuver decreases venous return (preload). In AS, reduced preload leads to less blood flowing across the stenotic valve [3], thereby **decreasing** the murmur's intensity. **Why other options are incorrect:** * **HOCM:** While HOCM also presents with a systolic ejection murmur and syncope, the murmur **increases** in intensity with Valsalva (due to decreased LV volume increasing outflow obstruction) [3]. It typically does not radiate to the carotids. * **Mitral Regurgitation (MR):** MR presents with a **holosystolic** (pansystolic) murmur heard best at the apex radiating to the axilla, not an ejection murmur radiating to the carotids. * **Tricuspid Regurgitation (TR):** TR is a holosystolic murmur heard at the left lower sternal border that **increases with inspiration** (Carvallo's sign). **NEET-PG High-Yield Pearls:** * **SAD Triad of AS:** **S**yncope, **A**ngina, and **D**yspnea (indicates heart failure). * **Pulsus Parvus et Tardus:** A small-amplitude, delayed carotid pulse is a classic sign of severe AS. * **Dynamic Auscultation:** Most murmurs decrease with Valsalva/Standing (decreased preload) **EXCEPT** HOCM and Mitral Valve Prolapse (MVP), which increase [3].

Question 1017: Cardiomyopathy may be seen in all of the following conditions except?

A. Duchene muscular dystrophy
B. Friedreich's ataxia
C. Type II glycogen storage disease
D. Alkaptonuria (Correct Answer)

Explanation: **Explanation:** The correct answer is **Alkaptonuria**. This question tests your ability to differentiate between systemic diseases that involve the myocardium (causing cardiomyopathy) and those that primarily affect the valvular or vascular structures. **1. Why Alkaptonuria is the correct answer:** Alkaptonuria is an autosomal recessive disorder caused by a deficiency of **homogentisate 1,2-dioxygenase**, leading to the accumulation of homogentisic acid. While it has significant cardiovascular manifestations due to pigment deposition (ochronosis), it typically causes **valvular heart disease** (most commonly aortic stenosis) and **coronary artery disease** (due to accelerated atherosclerosis). It does not typically result in primary cardiomyopathy. **2. Why the other options are incorrect:** * **Duchenne Muscular Dystrophy (DMD):** Dystrophin is present in both skeletal and cardiac muscle. Its absence leads to progressive fibrosis of the myocardium, typically resulting in **Dilated Cardiomyopathy (DCM)** [1]. * **Friedreich's Ataxia:** This is the most common inherited ataxia. Up to 90% of patients develop cardiac involvement, most characteristically **Hypertrophic Cardiomyopathy (HCM)**, which can eventually progress to heart failure [2]. * **Type II Glycogen Storage Disease (Pompe Disease):** This is a lysosomal storage disorder (acid maltase deficiency). It is a classic cause of **massive cardiomegaly** and hypertrophic cardiomyopathy in infants due to excessive glycogen deposition in cardiac myocytes. **Clinical Pearls for NEET-PG:** * **Pompe Disease:** Look for "massive cardiomegaly" and "short PR interval" on ECG in an infant. * **Friedreich's Ataxia:** The most common cause of death is heart failure/arrhythmia due to cardiomyopathy. * **Alkaptonuria Triad:** Ochronotic arthritis, dark urine (on standing), and black pigmentation of the sclera/ear cartilage. Remember: **Valves, not Myocardium.**

Question 1018: A 64-year-old male presents with dyspnea and edema. He had previous coronary bypass surgery 5 years ago, which was uncomplicated. Since then he has had no further chest pain. On examination, his JVP is at 8 cm, with prominent Kussmaul's sign. The heart sounds are easily heard but there is an early diastolic filling sound (pericardial knock). For this patient, select the most likely diagnosis.

A. Cardiac tamponade
B. Constrictive pericarditis (Correct Answer)
C. Restrictive cardiomyopathy
D. Right ventricle myocardial infarction

Explanation: The clinical presentation of elevated JVP, **Kussmaul’s sign** (paradoxical rise in JVP during inspiration), and a **pericardial knock** (a high-pitched early diastolic sound) is classic for **Constrictive Pericarditis (CP)**. In this patient, the history of prior coronary artery bypass surgery is a significant risk factor, as post-surgical inflammation can lead to pericardial fibrosis and calcification [1]. #### **Why the Correct Answer is Right:** In CP, the rigid, non-compliant pericardium limits diastolic filling. The **pericardial knock** occurs due to the sudden cessation of rapid ventricular filling by the rigid pericardium. **Kussmaul’s sign** occurs because the stiff pericardium prevents the right heart from accommodating the increased venous return during inspiration, forcing the pressure back into the jugular veins. #### **Why Other Options are Wrong:** * **A. Cardiac Tamponade:** While it causes elevated JVP, it typically presents with muffled heart sounds (Beck’s triad) and **pulsus paradoxus**. Kussmaul’s sign is absent because the heart is compressed throughout the respiratory cycle, not just at the limit of filling. * **C. Restrictive Cardiomyopathy (RCM):** RCM shares many features with CP. However, a **pericardial knock is specific to CP**, whereas RCM is more likely to have an S3 or S4 gallop [2]. * **D. Right Ventricle MI:** This presents with hypotension and clear lungs in the setting of an acute inferior wall MI [3]. While JVP is elevated and Kussmaul’s sign may be present, the history of surgery 5 years ago and the presence of a pericardial knock point toward a chronic pericardial process. #### **NEET-PG High-Yield Pearls:** * **Most common cause of CP:** Worldwide – Tuberculosis; Developed countries – Idiopathic/Viral or Post-cardiac surgery. * **JVP Waveform in CP:** Prominent **'x' and 'y' descents** (Friedreich’s sign), giving a "W" or "M" shape. * **Imaging Gold Standard:** Cardiac MRI or CT (shows pericardial thickening >4mm). * **Treatment of choice:** Pericardiectomy.

Question 1019: All of the following are electrocardiographic features of hyperkalemia, except?

A. Prolonged PR interval
B. Prolonged QT interval (Correct Answer)
C. Sine wave patterns
D. Loss of P waves

Explanation: **Explanation:** Hyperkalemia is a critical electrolyte abnormality that alters the resting membrane potential of myocytes, leading to predictable sequential changes on an ECG [1]. **Why Prolonged QT Interval is the Correct Answer:** Hyperkalemia typically causes **shortening of the QT interval**, not prolongation. This occurs because high extracellular potassium levels increase the speed of repolarization (Phase 3 of the action potential), leading to narrow, peaked T waves and a shortened QT duration. In contrast, **Hypokalemia** is associated with QT prolongation (often due to prominent U waves). **Analysis of Incorrect Options:** * **Prolonged PR interval:** As potassium levels rise (typically >6.5 mEq/L), conduction through the atria and AV node slows down, leading to PR interval prolongation. * **Loss of P waves:** As toxicity progresses, the P wave flattens and eventually disappears (Atrial standstill) because the atrial myocardium becomes inexcitable [1]. * **Sine wave patterns:** This is a late, pre-terminal sign of severe hyperkalemia (>8.0 mEq/L). The QRS complex widens significantly and merges with the T wave, creating a characteristic sinusoidal appearance, which can rapidly degenerate into ventricular fibrillation or asystole [1]. **High-Yield NEET-PG Pearls:** * **Earliest sign:** Tall, "tented" or peaked T waves (best seen in V2-V4) [1]. * **Sequence of changes:** Peaked T waves → PR prolongation/P wave flattening → QRS widening → Sine wave → Asystole [1]. * **Treatment:** Calcium gluconate (stabilizes the cardiac membrane) is the first step if ECG changes are present [2], followed by insulin/dextrose and salbutamol to shift K+ intracellularly.

Question 1020: A 50-year-old man with aortic stenosis is exercising for 11 minutes according to the Bruce protocol. Exercise is stopped due to fatigue. The regional pressure gradient between the two sides of the aortic valve is 60 mm Hg. What is the best management?

A. Angiogram
B. Aortic valve replacement
C. Aortic ballooning to prevent further derangement
D. Observation (Correct Answer)

Explanation: **Explanation:** The management of Aortic Stenosis (AS) is primarily guided by the presence of symptoms and the severity of the stenosis. In this scenario, the patient is **asymptomatic** (fatigue at 11 minutes of the Bruce protocol is a normal physiological response, not an exercise-induced symptom) and has a pressure gradient of 60 mmHg, which classifies as **Severe AS** (Mean gradient >40 mmHg) [1]. **Why Observation is correct:** Current guidelines (ACC/AHA) state that for asymptomatic patients with severe AS and preserved Left Ventricular Ejection Fraction (LVEF), the management is **watchful waiting** (Observation). Exercise testing is used to unmask "latent" symptoms [1]. Since this patient completed 11 minutes (Stage IV of Bruce protocol) and only stopped due to general fatigue—not chest pain, dyspnea, or hypotension—the test is considered negative for symptoms. Therefore, surgery is not yet indicated. **Why other options are incorrect:** * **Aortic Valve Replacement (B):** This is the definitive treatment but is reserved for *symptomatic* severe AS, asymptomatic severe AS with LVEF <50%, or those undergoing other cardiac surgeries. * **Angiogram (A):** Usually performed as a preoperative workup before valve surgery to check coronary anatomy; it is not indicated in an asymptomatic patient being managed conservatively. * **Aortic Ballooning (C):** Balloon Valvotomy is generally a palliative measure or a "bridge to surgery" in unstable patients or children; it is not a standard preventive treatment for stable adults [1]. **Clinical Pearls for NEET-PG:** * **Classic Triad of AS:** Dyspnea (most common), Angina, and Syncope (**SAD**). * **Severe AS Criteria:** Valve Area <1.0 cm², Mean Gradient >40 mmHg, or Jet Velocity >4 m/s. * **Indication for Surgery in Asymptomatic AS:** LVEF <50%, drop in BP during exercise, or very severe AS (Velocity >5 m/s).

Practice by Chapter

Coronary Artery Disease and Angina

Practice Questions

Acute Coronary Syndromes

Practice Questions

Heart Failure

Practice Questions

Cardiac Arrhythmias

Practice Questions

Valvular Heart Diseases

Practice Questions

Cardiomyopathies

Practice Questions

Pericardial Diseases

Practice Questions

Congenital Heart Disease in Adults

Practice Questions

Hypertension and Hypertensive Emergencies

Practice Questions

Pulmonary Hypertension

Practice Questions

Non-invasive Cardiac Diagnostics

Practice Questions

Preventive Cardiology

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Cardiology — MCQs

Cardiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?