Cardiology Practice Questions

Q: Reperfusion is believed to restore contractile function of which of the following?

Hibernating Myocardium. ### Explanation The correct answer is **Hibernating Myocardium**. **1. Why Hibernating Myocardium is Correct:** Hibernating myocardium refers to a state of **chronic** but reversible left ventricular systolic dysfunction due to persistently reduced coronary blood flow (chronic ischemia) [1]. In this state, the myocytes remain viable but "downregulate" their metabolism and contractility to match the low oxygen supply, preventing irreversible necrosis [1]. The hallmark of hibernation is that **contractile function improves or is restored after reperfusion** (e.g., via CABG or PCI), provided intervention occurs before irreversible damage [2]. **2. Why the Other Options are Incorrect:** * **Stunned Myocardium (Option A):** This is a state of temporary contractile dysfunction that persists **after** blood flow has already been restored (post-ischemic dysfunction). Unlike hibernation, the blood flow is already normal, but the muscle takes time to recover. Reperfusion is the *cause* of the recovery process, not the trigger for restoration of function, as the flow is already present. * **Ischemic/Non-ischemic bled myocardium (Options C & D):** These terms are not standard clinical descriptors for reversible myocardial dysfunction. "Bled" (hemorrhagic) myocardium usually implies severe microvascular injury or reperfusion injury, which often leads to permanent damage rather than functional restoration. **3. NEET-PG Clinical Pearls:** * **Gold Standard for Viability:** PET scan (showing FDG uptake) is the gold standard to differentiate hibernating (viable) from infarcted (non-viable) tissue. * **Dobutamine Stress Echo:** Hibernating myocardium shows a **biphasic response** (improvement at low doses, worsening at high doses). * **Key Distinction:** * **Stunning:** Flow is normal; function is low (temporary). * **Hibernation:** Flow is low; function is low (reversible upon revascularization).

Q: A 26-year-old man attends an occupational health assessment. A 12-lead ECG is recorded. He is feeling well and has no symptoms or significant past medical history. Based on the ECG findings, what is the most likely diagnosis?

Wolff-Parkinson White Syndrome. ***Wolff-Parkinson White Syndrome*** - Classic **ECG triad** includes **short PR interval** ( 120ms) due to ventricular pre-excitation via an **accessory pathway**. - Often discovered **incidentally** in asymptomatic young individuals during routine screening, as the **accessory pathway** allows early ventricular activation bypassing the normal AV node conduction delay. *Right Bundle Branch Block* - Characterized by **wide QRS** (>120ms) with **RSR' pattern** in V1-V2 and **wide S waves** in leads I and V6, but **no delta wave** present. - Maintains **normal PR interval** and lacks the characteristic **slurred upstroke** seen in pre-excitation syndromes. *Brugada Syndrome* - Distinguished by **coved ST elevation** in leads V1-V2 with **downsloping ST segments**, not delta waves or short PR intervals. - Associated with **sodium channel mutations** and risk of **ventricular arrhythmias**, but ECG shows normal PR interval and narrow QRS when not in arrhythmia. *Normal Variant* - Would show **normal PR interval** (120-200ms), **narrow QRS complex** (<120ms), and **absence of delta waves**. - Lacks any of the characteristic pre-excitation findings that suggest an **accessory pathway** or conduction abnormality.

Q: Which of the following investigations can detect the volume of infarcted area in acute myocardial infarction?

Echocardiography. The correct answer is **Echocardiography (Option A)**. In the setting of acute myocardial infarction (AMI), Echocardiography is the most practical bedside tool to assess the **volume and extent of the infarcted area** [1]. It detects regional wall motion abnormalities (RWMA) that occur almost immediately after coronary occlusion. By visualizing which segments of the myocardium are hypokinetic, akinetic, or dyskinetic, clinicians can estimate the "area at risk" and the total volume of functional loss. **Why other options are incorrect:** * **Electrocardiography (ECG):** While ECG is the gold standard for initial diagnosis and localization (e.g., Anterior vs. Inferior), it reflects electrical changes rather than physical volume [2]. It cannot precisely quantify the cubic volume of infarcted tissue. * **CPK-MB:** Cardiac enzymes correlate with the *magnitude* of myocardial necrosis, but they provide a biochemical estimate rather than a spatial or volumetric measurement of the infarct. * **Thallium Scan:** Thallium-201 is a "cold spot" scan used primarily for assessing myocardial viability and perfusion. While it can show areas of decreased uptake, it is rarely used in the *acute* phase to measure infarct volume due to its logistical complexity compared to Echo. **NEET-PG High-Yield Pearls:** * **Echo in AMI:** The earliest sign of ischemia on Echo is systolic wall thinning and reduced inward motion (RWMA) [1]. * **Gold Standard:** While Echo is the practical choice, **Cardiac MRI (Delayed Gadolinium Enhancement)** is the most accurate "Gold Standard" for quantifying infarct size and transmurality [3]. * **Negative Predictive Value:** A normal Echocardiogram during active chest pain has a very high negative predictive value for ruling out a large MI.

Q: All of the following can occur in rheumatic fever except?

Loud first heart sound. **Explanation:** The correct answer is **Loud first heart sound (S1)** because, in the **acute phase** of Rheumatic Fever (RF), the S1 is typically **soft or muffled**, not loud. **1. Why "Loud S1" is the correct choice (The Exception):** Acute Rheumatic Fever causes **pancarditis** [1]. Inflammation of the myocardium (myocarditis) leads to a prolonged PR interval (First-degree AV block). A prolonged PR interval allows the mitral valve leaflets to float back toward a semi-closed position before ventricular systole begins, resulting in a **soft S1**. Additionally, acute mitral regurgitation (common in RF) [2] further softens the S1. A *loud* S1 is a hallmark of chronic, calcified Mitral Stenosis, not the acute inflammatory phase of RF. **2. Analysis of Incorrect Options:** * **Mitral Regurgitation (MR):** This is the **most common** valvular abnormality in acute rheumatic carditis [2]. It occurs due to annular dilatation or chordal inflammation, presenting as a pansystolic murmur at the apex. * **Mitral Stenosis (MS):** While MS is a **chronic** sequela of rheumatic heart disease (occurring years later), the question asks what *can* occur in rheumatic fever (encompassing the disease spectrum). However, in the acute phase, a "Carey Coombs murmur" (a mid-diastolic murmur) can mimic MS due to valvulitis. * **Pericarditis:** As part of the **pancarditis** (endocarditis, myocarditis, and pericarditis) [1], patients can develop pericardial friction rubs or effusions. **Clinical Pearls for NEET-PG:** * **Most common valve involved:** Mitral > Aortic > Tricuspid > Pulmonary. * **Carey Coombs Murmur:** A short, mid-diastolic murmur heard in acute RF due to mitral valve leaflet edema (distinguish from the opening snap of chronic MS). * **Jones Criteria:** Remember that Carditis is a **Major** criterion, while a prolonged PR interval is a **Minor** criterion.

Q: A 70-year-old male with a history of hypertension and diabetes mellitus presents with the following rhythm, accompanied by a blood pressure of 90/40 mm Hg and a feeble pulse. What is the next step in management?

DC cardioversion. ***DC cardioversion*** - The patient presents with **hemodynamic instability** (BP 90/40 mmHg, feeble pulse) requiring **immediate electrical cardioversion** per ACLS guidelines. - **Synchronized DC cardioversion** is the first-line treatment for any **hemodynamically unstable tachyarrhythmia** regardless of rhythm type. *IV adenosine* - **Adenosine** is used for stable patients with **narrow-complex SVT** and requires hemodynamic stability for safe administration. - In **hemodynamically unstable** patients, pharmacological agents delay definitive treatment and can worsen hypotension. *IV diltiazem* - **Diltiazem** is a calcium channel blocker used for **rate control** in stable atrial fibrillation or atrial flutter. - It can cause **further hypotension** and is contraindicated in hemodynamically unstable patients. *Ibutilide* - **Ibutilide** is used for **chemical cardioversion** of atrial fibrillation/flutter in hemodynamically stable patients. - It requires **continuous cardiac monitoring** and is inappropriate when immediate intervention is needed for instability.

Q: A patient with myocardial infarction presents with nausea, vomiting, epigastric pain, and bradycardia. ECG shows a first-degree heart block. What is the most commonly involved coronary artery in this scenario?

Right coronary artery. **Explanation:** The clinical presentation described—nausea, vomiting, epigastric pain, bradycardia, and heart block—is classic for an **Inferior Wall Myocardial Infarction (IWMI)**. **1. Why the Right Coronary Artery (RCA) is correct:** * **Anatomy:** In approximately 80–85% of individuals (right-dominant circulation), the RCA gives off the posterior descending artery, which supplies the inferior wall of the left ventricle. * **Conduction System:** The RCA supplies the **SA node** (in 60% of cases) and the **AV node** (in 90% of cases). Ischemia to the RCA often leads to bradyarrhythmias and AV blocks (like the first-degree block mentioned) [3]. * **Bezold-Jarisch Reflex:** Ischemia of the inferior wall stimulates vagal afferent fibers, leading to the "Vagal Triad" of hypotension, bradycardia, and nausea/vomiting [2]. **2. Why the other options are incorrect:** * **Left Anterior Descending (LAD):** Supplies the anterior wall and septum. LAD infarcts typically present with tachycardia (due to sympathetic surge) and bundle branch blocks, rather than bradycardia. * **Left Circumflex (LCx):** Supplies the lateral wall. While it can supply the inferior wall in "left-dominant" individuals (10%), it is statistically less common than the RCA [1]. * **Oblique Artery:** This is a small branch (e.g., the oblique vein of Marshall or small atrial branches) and is not a major epicardial vessel responsible for MI. **High-Yield Clinical Pearls for NEET-PG:** * **Right Ventricular MI:** Always suspect this in IWMI patients with hypotension and clear lungs. **Avoid Nitrates** in these patients as they are preload-dependent. * **ECG Leads:** Inferior wall MI is seen in leads **II, III, and aVF** [1]. * **Autonomic Association:** Inferior MI = Parasympathetic (Vagal) signs; Anterior MI = Sympathetic signs [2].

Q: Which of the following is NOT true about Hypertrophic Obstructive Cardiomyopathy?

Beta-2 agonists are useful. Hypertrophic Obstructive Cardiomyopathy (HOCM) is characterized by a dynamic pressure gradient in the Left Ventricular Outflow Tract (LVOT). The severity of this obstruction is inversely proportional to the **Left Ventricular (LV) volume**. Anything that decreases LV volume (decreased preload/afterload) or increases contractility will worsen the obstruction [1]. **Why Option A is the correct answer (False statement):** Beta-2 agonists (like Salbutamol) are **contraindicated** in HOCM. They cause peripheral vasodilation (decreasing afterload) and have mild positive inotropic effects. Both actions decrease the LV end-diastolic volume and increase the LVOT gradient, thereby worsening the obstruction and symptoms. **Analysis of other options:** * **Option B:** Asymmetrical Septal Hypertrophy (ASH) is the hallmark of HOCM, where the interventricular septum is significantly thicker than the posterior wall (Ratio >1.3:1) [1]. * **Option C:** The obstruction is "dynamic" because it varies with the cardiac cycle and loading conditions, often involving the **Systolic Anterior Motion (SAM)** of the mitral valve. * **Option D:** Passive leg raising increases venous return (preload). Increased LV volume pushes the septum away from the mitral valve, widening the LVOT and **improving** (decreasing) the murmur intensity. **High-Yield Clinical Pearls for NEET-PG:** 1. **Murmur Dynamics:** The HOCM murmur (harsh systolic) **increases** with Valsalva and standing (decreased preload) and **decreases** with Squatting and Handgrip (increased preload/afterload). 2. **Drug of Choice:** Beta-blockers (e.g., Metoprolol) are the first-line treatment as they increase diastolic filling time and decrease contractility. 3. **Avoid:** Nitrates, Diuretics, and ACE inhibitors, as they reduce preload/afterload and worsen the gradient [1].

Question 1

Reperfusion is believed to restore contractile function of which of the following?

Accepted Answer

Hibernating Myocardium

Answer

Stunned Myocardium

Answer

Ischemic non-bled myocardium

Answer

Non ischemic bled myocardium

Question 2

A 71-year-old man presents with blurry vision and blood-tinged urine. He has a history of hypertension treated with a beta-blocker, an ACE inhibitor, and a calcium channel blocker. His symptoms began 3 days ago when he stopped his medications. His blood pressure is 200/110 mmHg, funduscopic examination reveals flame hemorrhages and papilledema, and urinalysis shows red blood cells with dysmorphic red blood cell casts. He has an abdominal bruit. What is the most appropriate next step in management?

Accepted Answer

Administer intravenous medication to reduce his blood pressure.

Answer

Order an ECG and observe the patient.

Answer

Order an abdominal CT scan to rule out aortic aneurysm.

Answer

Administer the patient's usual daily doses of blood pressure medications and observe him.

Question 3

Which of the following is a criterion for cardiac shock?

Accepted Answer

Systolic blood pressure < 90 mm Hg

Answer

Diastolic blood pressure < 80 mm Hg

Answer

Cardiac index < 3.5 L/min/m

Answer

Stroke volume 70 ml

Question 4

A 26-year-old man attends an occupational health assessment. A 12-lead ECG is recorded. He is feeling well and has no symptoms or significant past medical history. Based on the ECG findings, what is the most likely diagnosis?

Accepted Answer

Wolff-Parkinson White Syndrome

Answer

Right Bundle Branch Block

Answer

Brugada Syndrome

Answer

Normal Variant

Question 5

Which of the following investigations can detect the volume of infarcted area in acute myocardial infarction?

Accepted Answer

Echocardiography

Answer

Electrocardiography

Answer

Levels of Creatine Phosphokinase-MB

Answer

Thallium scan

Question 6

Brugada syndrome is associated with which of the following ECG findings?

Accepted Answer

Right Bundle Branch Block

Answer

Left Bundle Branch Block

Answer

Left Anterior Fascicular block

Answer

Left Posterior Fascicular block

Question 7

All of the following can occur in rheumatic fever except?

Accepted Answer

Loud first heart sound

Answer

Mitral regurgitation

Answer

Mitral stenosis

Answer

Pericarditis

Question 8

A 70-year-old male with a history of hypertension and diabetes mellitus presents with the following rhythm, accompanied by a blood pressure of 90/40 mm Hg and a feeble pulse. What is the next step in management?

Accepted Answer

DC cardioversion

Answer

IV adenosine

Answer

IV diltiazem

Answer

Ibutilide

Question 9

A patient with myocardial infarction presents with nausea, vomiting, epigastric pain, and bradycardia. ECG shows a first-degree heart block. What is the most commonly involved coronary artery in this scenario?

Accepted Answer

Right coronary artery

Answer

Left anterior descending artery

Answer

Oblique artery

Answer

Left circumflex coronary artery

Question 10

Which of the following is NOT true about Hypertrophic Obstructive Cardiomyopathy?

Accepted Answer

Beta-2 agonists are useful

Answer

Asymmetrical hypertrophy of the septum

Answer

Dynamic left ventricular outflow obstruction

Answer

The condition improves on passive leg raising

Cardiology — MCQs

Cardiology — MCQs

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