Cardiology Practice Questions

Q: A 50-year-old male has had precordial pain for four hours. On examination, his BP is 110/80 mm Hg, pulse is 120 beats/min, and respiratory rate is 26/min. His ECG shows marked ST segment elevation in leads V3-V6 and left ventricular ectopics. What are the initial therapeutic modalities in this case?

Streptokinase and morphine. ### Explanation **1. Analysis of the Correct Answer (Option B)** The patient presents with classic features of an **Acute ST-Elevation Myocardial Infarction (STEMI)** involving the anterolateral wall (ST elevation in V3-V6). The two primary goals in the initial management of STEMI are **pain relief** and **reperfusion**. * **Morphine:** It is the analgesic of choice for STEMI [1]. It reduces pain, decreases sympathetic activity (lowering heart rate and BP), and acts as a venodilator, which reduces cardiac preload and oxygen demand. * **Streptokinase:** As a fibrinolytic agent, it is indicated for reperfusion in STEMI if the patient presents within 12 hours of symptom onset and Primary PCI is not immediately available [2]. **2. Why Other Options are Incorrect** * **Option A & D (Lignocaine):** Historically, Lignocaine was used for prophylactic suppression of Ventricular Premature Beats (VPBs/ectopics) in MI. However, current guidelines **strongly discourage** prophylactic anti-arrhythmics as they do not improve survival and may increase the risk of bradycardia or asystole. Ectopics usually resolve once ischemia is treated. * **Option C (Dobutamine):** Dobutamine is an inotropic agent used in cardiogenic shock. This patient’s BP (110/80 mmHg) is stable; adding an inotrope would unnecessarily increase myocardial oxygen consumption and worsen ischemia/arrhythmias. **3. NEET-PG High-Yield Pearls** * **Time is Muscle:** The "Golden Hour" for thrombolysis is the first 60 minutes. * **Drug of Choice for Pain:** Morphine (avoid NSAIDs except Aspirin, as they increase the risk of myocardial rupture) [1]. * **Arrhythmia Management:** In the setting of acute MI, the most common cause of death in the pre-hospital phase is **Ventricular Fibrillation**. However, routine use of Lignocaine is contraindicated. * **Reperfusion Criteria:** ST elevation >1mm in two contiguous limb leads or >2mm in precordial leads.

Q: What is the most common complication of sub-valvular aortic stenosis?

Aortic regurgitation. **Explanation:** **Sub-valvular aortic stenosis (Sub-AS)**, most commonly occurring as a discrete sub-aortic membrane, creates a high-velocity, turbulent jet of blood just below the aortic valve. **Why Aortic Regurgitation (AR) is the correct answer:** The primary mechanism for AR in sub-valvular stenosis is twofold: 1. **Mechanical Trauma:** The turbulent jet produced by the sub-aortic obstruction constantly strikes the delicate aortic valve leaflets. This leads to progressive thickening, fibrosis, and scarring of the cusps. 2. **Venturi Effect:** The high-velocity flow creates a suction effect that can cause malcoaptation of the leaflets. Over time, these structural changes prevent the valve from closing properly, making **Aortic Regurgitation** the most frequent complication, seen in over 50% of patients [1]. **Why other options are incorrect:** * **B, C, and D (MR, TR, PR):** While chronic left ventricular pressure overload from sub-AS can eventually lead to left ventricular dilatation and secondary (functional) mitral regurgitation, it is not the *most common* or direct complication. Tricuspid and pulmonary valves are located in the right heart and are hemodynamically distant from the sub-aortic turbulence. **High-Yield Clinical Pearls for NEET-PG:** * **Associated Lesions:** Sub-AS is frequently associated with VSD, PDA, or Coarctation of the aorta. * **Infective Endocarditis:** Patients with sub-AS are at a significantly higher risk for infective endocarditis compared to those with valvular AS due to the high-velocity jet damaging the endothelium. * **Surgical Timing:** Surgery is often indicated not just to relieve the gradient, but specifically to prevent the progression of irreversible aortic regurgitation. * **Echocardiography:** The "gold standard" for diagnosis, often showing a "thin membrane" or "tunnel-like" narrowing in the LV outflow tract.

Q: Persistence of ST-segment elevation in ECG in a case of Myocardial infarction is suggestive of which of the following?

Left Ventricular Aneurysm. **Explanation:** In the natural evolution of an acute ST-elevation myocardial infarction (STEMI), the ST segment typically returns to the baseline within hours to days following reperfusion or the completion of the infarct [1]. The **persistence of ST-segment elevation beyond 2 weeks** after an acute MI is a classic electrocardiographic hallmark of a **Left Ventricular (LV) Aneurysm** [2]. **Why Left Ventricular Aneurysm is correct:** An LV aneurysm occurs when a weakened area of the ventricular wall becomes thin and scarred, resulting in a paradoxical outward bulging (dyskinesia) during systole [2]. The persistent ST elevation is thought to result from the continuous mechanical stress and "stretching" of the viable myocardium at the border zone of the fibrotic aneurysm, creating a "current of injury" that never fully resolves. **Analysis of Incorrect Options:** * **A. Death of the patient:** While ECG activity ceases at death (asystole), persistent ST elevation is a clinical sign in a living patient. * **C. Normal finding:** ST elevation is always pathological in the context of post-MI follow-up and indicates either ongoing ischemia, pericarditis, or structural complications. * **D. Ventricular fibrillation:** This is a lethal arrhythmia characterized by chaotic, irregular electrical activity without identifiable P waves, QRS complexes, or ST segments. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** The apex and anterior wall (following LAD occlusion). * **ECG finding:** Persistent ST elevation + well-developed Q waves in the same leads [2]. * **Complications:** Heart failure, mural thrombus (leading to systemic embolism), and ventricular arrhythmias [2]. * **Imaging Gold Standard:** Echocardiography (shows localized dyskinesia/aneurysmal bulge) [2]. * **Note:** Unlike acute MI, these patients are usually asymptomatic or present with chronic heart failure rather than acute chest pain [2].

Q: Left atrial enlargement is seen in which of the following conditions?

Mitral stenosis. **Explanation:** **1. Why Mitral Stenosis (MS) is Correct:** In Mitral Stenosis, there is a narrowing of the mitral valve orifice, which creates a pressure gradient between the left atrium (LA) and the left ventricle (LV) during diastole. To overcome this resistance and maintain ventricular filling, the **Left Atrial pressure increases**. Over time, this chronic pressure overload leads to compensatory **Left Atrial hypertrophy and dilatation**. LA enlargement is a hallmark of MS and is often visible on an ECG as *P-mitrale* (broad, notched P-waves) and on a Chest X-ray as a "double atrial shadow" or straightening of the left cardiac border. **2. Why the Other Options are Incorrect:** * **Tricuspid Regurgitation (TR):** This involves the valve between the right atrium and right ventricle. TR leads to volume overload and enlargement of the **Right Atrium** and Right Ventricle, not the left side. * **Aortic Regurgitation (AR):** In AR, blood flows back from the aorta into the **Left Ventricle** during diastole. This primarily causes massive **Left Ventricular dilatation** (eccentric hypertrophy). While severe chronic AR can eventually lead to secondary LA enlargement due to elevated LV end-diastolic pressure, it is not the primary or classic association compared to MS. **Clinical Pearls for NEET-PG:** * **Most common cause of LA enlargement:** Mitral Stenosis (often due to Rheumatic Heart Disease). * **Complication:** Significant LA enlargement is a major risk factor for the development of **Atrial Fibrillation** and subsequent systemic thromboembolism. * **X-ray Sign:** Look for "Ortner’s Syndrome"—hoarseness of voice caused by a giant left atrium compressing the left recurrent laryngeal nerve. * **Echocardiography:** The gold standard for diagnosing and quantifying the severity of LA enlargement.

Q: Which of the following ECG changes in an asymptomatic athlete's heart should be considered pathological?

Prolonged QTc interval. The "Athlete’s Heart" refers to physiological structural and electrical remodeling resulting from regular, intense physical training. Distinguishing these benign adaptations from potentially fatal pathologies (like Hypertrophic Cardiomyopathy or Channelopathies) is a high-yield competency for NEET-PG. **Why Prolonged QTc is Pathological:** A **prolonged QTc interval (>470 ms in males, >480 ms in females)** is never considered a normal physiological adaptation to exercise [1]. It suggests an underlying **Long QT Syndrome (LQTS)**, which predisposes the athlete to Torsades de Pointes and sudden cardiac death [2]. While athletes often have bradycardia (which naturally lengthens the absolute QT), the *corrected* QT (QTc) should remain within normal limits [1]. **Analysis of Incorrect Options:** * **A. Increased QRS Amplitude:** This is a common, benign finding in athletes representing physiological Left Ventricular Hypertrophy (LVH) due to volume or pressure loads during training. * **B. Mobitz Type 1 (Wenckebach) Block:** High vagal tone in athletes frequently causes resting bradycardia, First-degree AV block, or Mobitz Type 1. These are benign and typically disappear with exercise or sympathetic stimulation. * **D. T-wave Inversion (TWI):** While TWI in lateral leads (V5-V6) is concerning, TWI in leads **V1–V3** is considered a common physiological variant in **Black athletes** (the "African/Afro-Caribbean pattern"). Since the option does not specify the leads, and QTc prolongation is universally pathological, QTc is the definitive answer. **Clinical Pearls for NEET-PG:** * **Normal Athlete ECG:** Sinus bradycardia, Early repolarization (ST-elevation with J-point notch), and incomplete RBBB. * **Pathological Findings:** Q-waves (>3mm depth), T-wave inversion in lateral leads, and QTc prolongation. * **International Criteria:** Always use the "Seattle Criteria" or "International Recommendations" to differentiate athlete ECGs.

Q: Pulsus bigeminy is seen in patients treated with which of the following medications?

Digitalis. **Explanation:** **Pulsus Bigeminy** is a rhythm characterized by pairs of heartbeats, where a normal sinus beat is followed by a premature ventricular contraction (PVC). This results in a pulse pattern of a strong beat followed by a weaker, premature beat, with a compensatory pause before the next cycle. **Why Digitalis is the correct answer:** Digitalis (Digoxin) toxicity is the most classic cause of pulsus bigeminy. Digoxin inhibits the Na+/K+ ATPase pump, leading to increased intracellular calcium. This high calcium concentration can cause **delayed after-depolarizations (DADs)**, which trigger premature ventricular contractions [1]. When these PVCs occur consistently after every sinus beat, it manifests as bigeminy [1]. In the context of NEET-PG, bigeminy is considered a hallmark ECG finding of Digoxin toxicity [2]. **Why other options are incorrect:** * **Beta-Blockers:** These drugs decrease sympathetic activity and are actually used to *suppress* arrhythmias and PVCs. They typically cause bradycardia, not bigeminal rhythms. * **ACE Inhibitors:** These primarily affect the renin-angiotensin system to lower blood pressure and are not associated with triggering ventricular ectopy. * **Calcium Channel Blockers (CCBs):** Non-dihydropyridines (like Verapamil) slow the heart rate and AV conduction but do not typically cause bigeminy. **High-Yield Clinical Pearls for NEET-PG:** * **Most common ECG finding in Digoxin toxicity:** PVCs (often presenting as bigeminy) [1]. * **Most characteristic/specific ECG finding:** Atrial Tachycardia with AV block. * **The "Reverse Tick" sign:** ST-segment depression (sagging) seen in patients on therapeutic doses of Digoxin (not necessarily toxicity). * **Electrolyte Precursor:** Hypokalemia increases the risk of Digoxin toxicity because K+ and Digoxin compete for the same binding site on the Na+/K+ ATPase pump.

Q: In a patient with myocardial infarction, which valvular lesion is commonly seen?

Mitral regurgitation. **Explanation:** **Mitral Regurgitation (MR)** is a common and significant complication following myocardial infarction (MI). The underlying mechanism is usually **papillary muscle dysfunction** or, more severely, **papillary muscle rupture**. The mitral valve apparatus relies on the integrity of the chordae tendineae and papillary muscles; when an MI (particularly an inferior wall MI) affects the blood supply to these muscles (most commonly the posteromedial papillary muscle), the valve leaflets fail to coapt properly, leading to acute or chronic MR [1]. **Analysis of Incorrect Options:** * **Aortic Stenosis (A):** This is typically a chronic, degenerative, or congenital process (e.g., senile calcification or bicuspid valve) and is not acutely caused by myocardial ischemia. * **Aortic Regurgitation (C):** This usually results from aortic root dilation (e.g., dissection, Marfan syndrome) or valve leaflet damage (e.g., endocarditis), not from ventricular wall motion abnormalities seen in MI [2]. * **Septal Defect (D):** While a **Ventricular Septal Rupture (VSR)** is a known mechanical complication of MI, it is a "septal defect" rather than a "valvular lesion." MR remains the more frequent valvular finding [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Posteromedial Papillary Muscle:** Most commonly involved in MI because it has a **single blood supply** (usually the Right Coronary Artery), making it more vulnerable than the anterolateral muscle, which has dual supply (LAD and LCx). * **Timing:** Acute MR typically occurs **2 to 7 days** post-MI. * **Clinical Sign:** A new-onset **pansystolic murmur** at the apex radiating to the axilla [1]. * **Diagnosis:** Echocardiography is the gold standard for confirming the severity and mechanism of MR post-MI [1], [3].

Q: Which of the following is true in mitral regurgitation (MR)?

Pansystolic murmur at the apex. In Mitral Regurgitation (MR), there is a backflow of blood from the high-pressure Left Ventricle (LV) to the low-pressure Left Atrium (LA) throughout the entire systolic phase [1]. Because the pressure gradient between the LV and LA remains significant from the beginning of isovolumetric contraction (closure of mitral valve) until the end of isovolumetric relaxation (opening of mitral valve), the murmur is **pansystolic (holosystolic)**. It is best heard at the **apex** and typically radiates to the **axilla** [1]. **2. Why Other Options are Incorrect:** * **B. Loud S1:** In chronic MR, the S1 is usually **soft or muffled** because the mitral valve leaflets fail to coapt properly. A loud S1 is a hallmark of Mitral Stenosis. * **C. Functional/Secondary MR:** Functional MR occurs due to LV dilatation (e.g., dilated cardiomyopathy) which displaces papillary muscles and stretches the mitral annulus [1]. Papillary muscle rupture post-MI causes **Acute Organic MR**, not functional MR. * **D. ECG Findings:** MR leads to Left Atrial Enlargement (LAE), which manifests as **'P' mitrale** (broad, notched P waves in Lead II). 'P' pulmonale (tall, peaked P waves) is a sign of Right Atrial Enlargement. **Clinical Pearls for NEET-PG:** * **Murmur Dynamics:** The MR murmur does *not* increase with inspiration (unlike tricuspid regurgitation) but increases with **handgrip** (increased afterload). * **S3 Gallop:** The presence of an S3 in MR indicates severe volume overload and LV dysfunction [1]. * **Acute vs. Chronic:** Acute MR (e.g., chordae tendineae rupture) presents with a decrescendo systolic murmur and pulmonary edema, whereas chronic MR allows for compensatory chamber dilatation [1].

Question 1

A 50-year-old male has had precordial pain for four hours. On examination, his BP is 110/80 mm Hg, pulse is 120 beats/min, and respiratory rate is 26/min. His ECG shows marked ST segment elevation in leads V3-V6 and left ventricular ectopics. What are the initial therapeutic modalities in this case?

Accepted Answer

Streptokinase and morphine

Answer

Lignocaine and streptokinase

Answer

Morphine and dobutamine

Answer

Lignocaine, streptokinase and morphine

Question 2

Which of the following is used to prevent recurrence of a rhythm disorder?

Accepted Answer

Catheter ablation

Answer

Adenosine

Answer

Synchronized defibrillation with 120 Joules biphasic

Answer

Non-synchronized DC shock 200 Joules biphasic

Question 3

In Wolff-Parkinson-White syndrome, all of the following are true except?

Accepted Answer

Right bundle branch block pattern is seen in type B WPW syndrome.

Answer

Digoxin is contraindicated.

Answer

Short PR interval.

Answer

Broad QRS complex.

Question 4

What is the most common complication of sub-valvular aortic stenosis?

Accepted Answer

Aortic regurgitation

Answer

Mitral regurgitation

Answer

Tricuspid regurgitation

Answer

Pulmonary regurgitation

Question 5

Persistence of ST-segment elevation in ECG in a case of Myocardial infarction is suggestive of which of the following?

Accepted Answer

Left Ventricular Aneurysm

Answer

Death of the patient

Answer

Normal finding

Answer

Ventricular fibrillation

Question 6

Left atrial enlargement is seen in which of the following conditions?

Accepted Answer

Mitral stenosis

Answer

Tricuspid regurgitation

Answer

Aortic regurgitation

Answer

None of the above

Question 7

Which of the following ECG changes in an asymptomatic athlete's heart should be considered pathological?

Accepted Answer

Prolonged QTc interval

Answer

Increased amplitude of QRS

Answer

Second Degree (Mobitz 1) heart block

Answer

T wave inversion

Question 8

Pulsus bigeminy is seen in patients treated with which of the following medications?

Accepted Answer

Digitalis

Answer

Beta Blockers

Answer

ACE inhibitors

Answer

Calcium channel blockers

Question 9

In a patient with myocardial infarction, which valvular lesion is commonly seen?

Accepted Answer

Mitral regurgitation

Answer

Aortic stenosis

Answer

Aortic regurgitation

Answer

Septal defect

Question 10

Which of the following is true in mitral regurgitation (MR)?

Accepted Answer

Pansystolic murmur at the apex

Answer

Loud S1

Answer

Functional or Secondary MR is caused by papillary muscle rupture after myocardial infarction

Answer

ECG commonly reveals 'P' pulmonale

Cardiology — MCQs

Cardiology — MCQs

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