Cardiology Practice Questions

Q: What is the preferred analgesic for pain associated with ST-elevation myocardial infarction (STEMI)?

Morphine. **Explanation:** **Morphine** is the preferred analgesic for pain management in ST-elevation myocardial infarction (STEMI) because it provides more than just potent analgesia. Its benefits in STEMI are twofold: 1. **Hemodynamic Effects:** Morphine acts as a **venodilator**, which reduces venous return (preload) and decreases the workload of the heart (myocardial oxygen demand). It also causes mild arterial vasodilation, reducing afterload. 2. **Anxiolytic Effect:** By relieving intense pain and anxiety, it reduces sympathetic nervous system activation, further lowering heart rate and blood pressure. **Why other options are incorrect:** * **Diclofenac (NSAIDs):** These are generally **contraindicated** in the acute phase of MI. NSAIDs (except Aspirin) increase the risk of myocardial rupture, impair infarct healing, and are associated with an increased risk of recurrent MI and heart failure due to pro-thrombotic effects. * **Paracetamol:** While safe, it lacks the potent analgesic and hemodynamic benefits (preload reduction) required to manage the severe ischemic pain of STEMI. * **Dicyclomine:** This is an anticholinergic/antispasmodic used for GI smooth muscle cramps; it has no role in cardiac pain. **High-Yield Clinical Pearls for NEET-PG:** * **Route:** Morphine should be given **Intravenously (IV)**. Intramuscular (IM) injections should be avoided in MI as they can interfere with CK-MB/Troponin levels and cause hematomas during thrombolysis. * **Caution:** Morphine can slow the absorption of oral antiplatelets (like Clopidogrel/Ticagrelor) due to delayed gastric emptying. * **Alternative:** If Morphine is unavailable or contraindicated (e.g., allergy), **Fentanyl** is the preferred alternative. * **Side Effect:** If Morphine causes excessive bradycardia or hypotension, **Atropine** is the antidote of choice.

Q: The following ECG represents?

P pulmonale. ***P pulmonale*** - Characterized by **tall, peaked P waves** (>2.5 mm) in leads II, III, and aVF, indicating **right atrial enlargement**. - The **tall, peaked appearance** results from increased right atrial depolarization forces, creating the characteristic narrow, pointed P wave morphology. *Rabbit ear pattern* - This refers to the **RSR' pattern** seen in **right bundle branch block (RBBB)** in leads V1-V2. - It involves **QRS complexes**, not P waves, and appears as two distinct peaks resembling rabbit ears. *Delta wave* - A **slurred upstroke** of the QRS complex seen in **Wolff-Parkinson-White (WPW) syndrome**. - Results from **pre-excitation** via an accessory pathway, causing early ventricular depolarization, not P wave abnormalities. *P mitrale* - Indicates **left atrial enlargement** with **broad, notched or bifid P waves** (>0.12 seconds) in lead II. - Associated with conditions like **mitral stenosis**, appearing broad and notched rather than tall and peaked.

Q: Which coronary artery is the most likely culprit for the inferior STEMI seen on the ECG shown below?

RCA occlusion by thrombus. ***RCA occlusion by thrombus*** - **ST elevation** in **inferior leads (II, III, aVF)** is the classic ECG pattern most likely caused by **right coronary artery (RCA)** occlusion, though it is not definitively proven by the ECG alone. - The RCA typically supplies the **inferior wall** of the left ventricle and often the **posterior wall**, making it the most likely culprit vessel. However, LCX occlusion can also produce inferior STEMI and should be considered. *LAD occlusion by thrombus* - LAD occlusion would show **ST elevation** in **anterior leads (V1-V6)** and possibly **lead I and aVL**. - This pattern represents **anterior wall MI**, not the inferior wall changes seen in this ECG. *LCX occlusion by thrombus* - LCX occlusion typically causes **ST elevation** in **lateral leads (I, aVL, V5-V6)** or **posterior changes**. - While LCX can also cause inferior STEMI, the RCA is the more common culprit for isolated inferior lead ST elevation. May show **reciprocal ST depression** in anterior leads rather than the inferior lead changes observed. *Right ventricular MI* - Right ventricular MI can occur alongside inferior STEMI (also typically due to RCA occlusion) but would require additional right-sided leads (e.g., ST elevation in V4R) for diagnosis. - The ECG shown does not provide evidence of right ventricular involvement, making this a less specific diagnosis based on the available findings.

Q: Recurrent ischemic events following thrombosis have been pathophysiologically linked to which of the following?

Lipoprotein A. **Explanation:** **Lipoprotein (a) [Lp(a)]** is the correct answer because it possesses a unique structural homology with **plasminogen** [3]. Lp(a) consists of an LDL-like particle bound to apolipoprotein(a) [3]. Due to its similarity to plasminogen, it competitively inhibits the binding of plasminogen to fibrin and endothelial cell receptors [2][3]. This inhibition impairs fibrinolysis (the breakdown of clots), leading to a pro-thrombotic state [3]. Consequently, patients with elevated Lp(a) are at a significantly higher risk for recurrent ischemic events and "rebound" thrombosis following an initial vascular insult [3]. **Analysis of Incorrect Options:** * **Antibodies to thrombolytic agents:** While antibodies (e.g., anti-streptokinase) can neutralize the efficacy of specific drugs, they do not represent the primary pathophysiological mechanism for generalized recurrent ischemic events across the population [1]. * **Fibrinopeptide A:** This is a marker of active thrombin generation and fibrin formation. While it indicates an ongoing clotting process, it is a *product* of thrombosis rather than the underlying structural driver of recurrence. * **Triglycerides:** While hypertriglyceridemia is a risk factor for atherosclerosis, it does not have the direct anti-fibrinolytic properties that link Lp(a) specifically to recurrent thrombotic events. **Clinical Pearls for NEET-PG:** * **Lp(a) Level:** Levels are genetically determined and remain relatively constant throughout life; they are not significantly affected by diet or statins. * **Niacin and PCSK9 inhibitors** are known to lower Lp(a) levels, though clinical outcomes are still being studied. * **High-Yield Association:** Elevated Lp(a) is an independent risk factor for premature coronary artery disease (CAD) and calcific aortic stenosis [3].

Q: Paradoxical splitting of the second heart sound is heard in which of the following conditions?

Left bundle branch block (LBBB). The second heart sound (S2) consists of two components: **A2 (Aortic)** and **P2 (Pulmonary)**. Normally, A2 precedes P2, and the gap increases during inspiration (Physiological Splitting) [1]. **Paradoxical (Reversed) Splitting** occurs when A2 is significantly delayed, causing it to occur *after* P2. **Why LBBB is the Correct Answer:** In **Left Bundle Branch Block (LBBB)**, there is delayed depolarization of the left ventricle. This results in delayed closure of the aortic valve (A2). Consequently, P2 occurs before A2. During inspiration, the normal delay of P2 moves it closer to the delayed A2, narrowing the split. During expiration, P2 occurs earlier, widening the gap between P2 and A2. This "reverse" behavior compared to normal physiology defines paradoxical splitting. **Analysis of Incorrect Options:** * **RBBB (Option A):** Causes delayed right ventricular contraction, further delaying P2. This leads to **Wide Physiological Splitting** (A2 and P2 are far apart, widening further on inspiration). * **ASD (Option B):** Characterized by **Fixed Splitting**. The constant volume overload of the right heart keeps the P2 delay constant, regardless of the respiratory cycle. * **VSD (Option C):** Typically causes **Wide Physiological Splitting** due to increased right-sided volume and delayed P2, or it may be associated with a loud single S2 if pulmonary hypertension develops (Eisenmenger syndrome). **NEET-PG High-Yield Pearls:** * **Paradoxical Splitting Causes:** LBBB, Aortic Stenosis (severe), HOCM, and Patent Ductus Aueriosus (PDA). * **Fixed Splitting:** Pathognomonic for Atrial Septal Defect (ASD). * **Wide Splitting:** RBBB, Pulmonary Stenosis, and Mitral Regurgitation (due to early A2). * **Mnemonic for Paradoxical Split:** "The **L**eft side is **L**ate" (**L**BBB, **A**ortic **S**tenosis).

Q: A 50-year-old female presents to the OPD with shortness of breath. On examination, she is hypotensive, has soft heart sounds, and elevated JVP. Her ECG shows a reduction in the amplitude of QRS complexes. Which of the following is the investigation of choice for diagnosing her condition?

2-D Echocardiography. ### Explanation **Diagnosis: Cardiac Tamponade** The clinical presentation describes **Beck’s Triad** (hypotension, muffled/soft heart sounds, and elevated JVP), which is the classic hallmark of cardiac tamponade. The ECG finding of **low voltage QRS complexes** [1] (and potentially electrical alternans) further supports the presence of a large pericardial effusion causing tamponade. **1. Why 2-D Echocardiography is the Correct Answer:** 2-D Echocardiography is the **investigation of choice** because it is rapid, non-invasive, and highly sensitive [1]. It can visualize the "swinging heart" within the pericardial fluid and identify critical diagnostic signs of tamponade, such as: * **Early diastolic collapse of the Right Ventricle (RV).** * **Late diastolic collapse of the Right Atrium (RA).** * Significant respiratory variation in transvalvular flows. **2. Why Other Options are Incorrect:** * **Ultrasonography (USG):** While "Focused Assessment with Sonography for Trauma" (FAST) can detect fluid, 2-D Echo is the specific gold standard for cardiac structural and hemodynamic assessment. * **PET Scan:** This is used for metabolic activity (e.g., oncology or myocardial viability) and has no role in the acute diagnosis of tamponade. * **M-mode Echocardiography:** While M-mode provides high temporal resolution to see the timing of wall collapse, it lacks the spatial context of 2-D imaging required for a comprehensive diagnosis. It is usually an adjunct to 2-D Echo, not the primary choice. **Clinical Pearls for NEET-PG:** * **Pulsus Paradoxus:** A key clinical sign (drop in systolic BP >10 mmHg during inspiration). * **ECG Finding:** **Electrical Alternans** (alternating QRS amplitude) is pathognomonic for large effusions [1]. * **Management:** The definitive treatment for cardiac tamponade is **urgent pericardiocentesis** [1]. * **Chest X-ray:** May show a "Water bottle" or "Money bag" heart appearance.

Q: An electrocardiogram (ECG) in a patient with a systolic ejection murmur that shows an incomplete bundle branch block in the precordial lead is most consistent with which of the following conditions?

A secundum atrial septal defect (ASD).. The clinical presentation of a **systolic ejection murmur** (due to increased flow across the pulmonary valve) combined with an **incomplete right bundle branch block (RBBB)** in the precordial leads (rsR' pattern in V1) is the classic hallmark of an **Atrial Septal Defect (ASD)** [1]. **1. Why Option A is Correct:** In an **Ostium Secundum ASD** (the most common type), the volume overload of the right ventricle causes a delay in depolarization, manifesting as an incomplete RBBB [1]. Crucially, the ECG in Secundum ASD typically shows **Right Axis Deviation (RAD)**. This distinguishes it from other types of ASDs. **2. Why the Other Options are Incorrect:** * **Option C & D:** Both **Ostium Primum ASD** and **Complete AV Canal Defects** also present with an incomplete RBBB; however, they are characteristically associated with **Left Axis Deviation (LAD)** due to the superior displacement of the AV node and conduction system. * **Option B:** A **Sinus Venosus ASD** is often associated with a **leftward shift of the P-wave axis** (inverted P waves in inferior leads) because the sinoatrial node is often displaced or dysfunctional, but it does not typically present with the classic isolated incomplete RBBB/RAD pattern of a Secundum ASD. **3. High-Yield Clinical Pearls for NEET-PG:** * **Auscultation:** Look for a **fixed, wide split S2**—this is the most diagnostic physical sign of an ASD. * **ECG Shortcut:** * ASD + Right Axis Deviation = **Secundum ASD**. * ASD + Left Axis Deviation = **Primum ASD**. * **Radiology:** Chest X-ray typically shows "hilar dance" (increased pulmonary plethora) and right-sided heart enlargement [2]. * **Most Common Type:** Secundum ASD (75% of cases), located in the region of the fossa ovalis [1].

Question 1

What is the preferred analgesic for pain associated with ST-elevation myocardial infarction (STEMI)?

Accepted Answer

Morphine

Answer

Diclofenac

Answer

Paracetamol

Answer

Dicyclomine

Question 2

All of the following are usual features of left atrial myxoma, except?

Accepted Answer

Markedly enlarged left atrium

Answer

Raised ESR

Answer

Pyrexia

Answer

Systemic embolism

Question 3

The following ECG represents?

Accepted Answer

P pulmonale

Answer

Rabbit ear pattern

Answer

Delta wave

Answer

P mitrale

Question 4

Which coronary artery is the most likely culprit for the inferior STEMI seen on the ECG shown below?

Accepted Answer

RCA occlusion by thrombus

Answer

LAD occlusion by thrombus

Answer

LCX occlusion by thrombus

Answer

Right ventricular MI

Question 5

Pulsus paradoxus is seen in which of the following conditions?

Accepted Answer

Emphysema/Asthma

Answer

Shock

Answer

Elderly

Answer

High output state

Question 6

Recurrent ischemic events following thrombosis have been pathophysiologically linked to which of the following?

Accepted Answer

Lipoprotein A

Answer

Antibodies to thrombolytic agents

Answer

Fibrinopeptide A

Answer

Triglycerides

Question 7

Paradoxical splitting of the second heart sound is heard in which of the following conditions?

Accepted Answer

Left bundle branch block (LBBB)

Answer

Right bundle branch block (RBBB)

Answer

Atrial septal defect (ASD)

Answer

Ventricular septal defect (VSD)

Question 8

A 50-year-old female presents to the OPD with shortness of breath. On examination, she is hypotensive, has soft heart sounds, and elevated JVP. Her ECG shows a reduction in the amplitude of QRS complexes. Which of the following is the investigation of choice for diagnosing her condition?

Accepted Answer

2-D Echocardiography

Answer

Ultrasonography (USG)

Answer

Positron Emission Tomography (PET)

Answer

M-mode Echocardiography

Question 9

All of the following are clinical features of myxoma, EXCEPT:

Accepted Answer

Hypertension

Answer

Fever

Answer

Clubbing

Answer

Embolic phenomenon

Question 10

An electrocardiogram (ECG) in a patient with a systolic ejection murmur that shows an incomplete bundle branch block in the precordial lead is most consistent with which of the following conditions?

Accepted Answer

A secundum atrial septal defect (ASD).

Answer

A sinus venosus ASD with partial anomalous pulmonary venous return (PAPVR).

Answer

An ostium primum atrial septal defect (ASD).

Answer

A complete atrioventricular canal defect.

Cardiology — MCQs

Cardiology — MCQs

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