Cardiology Practice Questions

Q: On an ECG tracing, the presence of right atrial hypertrophy is suggested by which of the following?

Tall spiky P wave. ### Explanation **1. Why "Tall spiky P wave" is correct:** The P wave on an ECG represents atrial depolarization. In **Right Atrial Hypertrophy (RAH)**, the increased muscle mass of the right atrium generates a higher electrical voltage during the initial phase of atrial activation. This results in a P wave that is **tall and peaked** (amplitude **>2.5 mm** in lead II). This morphology is classically referred to as **"P-pulmonale"** because it is frequently associated with chronic obstructive pulmonary disease (COPD) or pulmonary hypertension. **2. Analysis of Incorrect Options:** * **B. Widened P wave:** This is characteristic of **Left Atrial Hypertrophy (LAH)**. Since the left atrium is the last to depolarize, its enlargement extends the duration of the P wave (>0.12s), often resulting in a notched or "M-shaped" wave known as **P-mitrale**. * **C. Prolonged P-R interval:** This indicates a delay in conduction through the AV node, signifying a **First-degree AV block**, not atrial chamber enlargement. * **D. Increased P-Q segment:** The P-Q (or P-R) segment represents the time between the end of atrial depolarization and the start of ventricular depolarization. Its prolongation is typically seen in conditions affecting the AV node or in **pericarditis** (where PR-segment depression is a key finding). **3. High-Yield Clinical Pearls for NEET-PG:** * **P-pulmonale (RAH):** Tall, peaked P waves in Lead II, III, aVF (>2.5 mm). * **P-mitrale (LAH):** Wide, notched P waves in Lead II (>0.12s) and a deep terminal negative deflection in Lead V1. * **Bi-atrial Enlargement:** Shows features of both (tall and wide P waves). * **Common Causes of RAH:** Pulmonary stenosis, Tricuspid stenosis, and Cor pulmonale.

Q: Bradycardia is a feature of which type of myocardial infarction?

Inferior wall MI. **Explanation:** **Inferior wall myocardial infarction (MI)** is classically associated with bradycardia due to two primary pathophysiological mechanisms: 1. **Blood Supply to the Nodes:** In approximately 60% of individuals, the **Right Coronary Artery (RCA)** supplies the Sinoatrial (SA) node, and in 90%, it supplies the Atrioventricular (AV) node. Since the RCA is the culprit vessel in most inferior wall MIs, ischemia to these nodes leads to sinus bradycardia or AV blocks [2]. 2. **Bezold-Jarisch Reflex:** The inferior wall of the left ventricle is rich in vagal afferent fibers. Ischemia in this region triggers a parasympathetic reflex, resulting in the clinical triad of bradycardia, hypotension, and vasodilation. **Analysis of Incorrect Options:** * **Anteroseptal MI:** Usually involves the Left Anterior Descending (LAD) artery. This is more commonly associated with **tachycardia** (due to sympathetic activation) or bundle branch blocks rather than sinus bradycardia [1]. * **Lateral wall MI:** Involves the Left Circumflex (LCx) artery. While it can occasionally affect the SA node (in 40% of cases), it is not the classic or most frequent presentation for bradycardia compared to inferior MI. * **Posterior wall MI:** Often occurs alongside inferior or lateral MIs. While it may be associated with bradycardia if the RCA is involved, the primary association taught and tested is with the inferior wall. **High-Yield Facts for NEET-PG:** * **Drug of Choice:** Atropine is the initial treatment for symptomatic bradycardia in inferior MI [2]. * **Right Ventricular MI:** Always look for RV infarction in patients with inferior MI (seen in 40% of cases). Avoid nitrates in these patients as they are preload-dependent. * **ECG Findings:** Look for ST-elevation in leads II, III, and aVF [1].

Q: Hydrostatic Pulmonary edema with fluid in alveoli is usually seen when PCWP is?

25mmHg. **Explanation:** The development of hydrostatic pulmonary edema is governed by **Starling’s Law**, which describes the balance between hydrostatic and oncotic pressures. In a healthy state, the Pulmonary Capillary Wedge Pressure (PCWP)—a surrogate for left atrial pressure—ranges between **8–12 mmHg**. **Why 25 mmHg is correct:** Pulmonary edema occurs in stages as PCWP rises: 1. **Stage I (13–18 mmHg):** Increased lymphatic flow; minimal clinical findings. 2. **Stage II (18–25 mmHg):** **Interstitial edema** occurs. Fluid leaks into the perivascular and peribronchial spaces (seen as Kerley B lines on X-ray). 3. **Stage III (>25 mmHg):** The compensatory capacity of the lymphatics is overwhelmed, and fluid floods the **alveoli**. Therefore, frank alveolar edema with clinical features like rales and "bat-wing" opacities typically requires a PCWP **>25 mmHg** [1]. **Analysis of Incorrect Options:** * **A (>6 mmHg) & B (0 mmHg):** These are within or below the normal physiological range (8–12 mmHg). At these pressures, the oncotic pressure (approx. 25 mmHg) easily keeps fluid within the capillaries. * **C (15 mmHg):** This represents mild elevation (often seen in early heart failure or fluid overload) but typically only results in vascular redistribution (cephalization) rather than alveolar flooding. **NEET-PG High-Yield Pearls:** * **Normal PCWP:** 8–12 mmHg. * **Cephalization (Upper lobe diversion):** Seen at PCWP 12–18 mmHg. * **Kerley B Lines:** Seen at PCWP 18–25 mmHg. * **Bat-wing appearance:** Classic radiological sign of alveolar edema (PCWP >25 mmHg) [1]. * **Non-cardiogenic edema (e.g., ARDS):** Characterized by alveolar fluid with a **normal PCWP (<18 mmHg)** due to increased permeability rather than hydrostatic pressure.

Q: Reverse splitting of the first heart sound is heard in which condition?

Left Bundle Branch Block (LBBB). **Explanation:** The **First Heart Sound (S1)** is produced by the closure of the atrioventricular valves: the Mitral (M1) and Tricuspid (T1) valves [1]. Normally, M1 occurs slightly before T1 because the left ventricle depolarizes just before the right ventricle [2]. **Why LBBB is correct:** In **Left Bundle Branch Block (LBBB)**, there is a significant delay in the depolarization and subsequent contraction of the left ventricle. This causes the Mitral valve (M1) closure to be delayed so significantly that it occurs *after* the Tricuspid valve (T1) closure. This reversal of the normal sequence (T1 followed by M1) is termed **reversed (paradoxical) splitting of S1**. **Analysis of Incorrect Options:** * **RBBB (Option A):** In Right Bundle Branch Block, the depolarization of the right ventricle is delayed. This further delays T1, leading to an **exaggerated (wide) normal split** (M1 followed by a much later T1), rather than a reversal. * **Tricuspid Stenosis (Option C):** This condition typically results in a loud S1 due to the elevated right atrial pressure keeping the valve wide open until the last moment, but it does not characteristically cause reverse splitting. * **Aortic Regurgitation (Option D):** AR primarily affects the second heart sound (S2) and may cause a soft S1 due to early closure of the mitral valve (from high LV end-diastolic pressure), but it is not a classic cause of reversed S1 splitting. **High-Yield Clinical Pearls for NEET-PG:** * **Reversed S1** is rare and seen in: LBBB, Right Ventricular Pacing, and severe Mitral Stenosis. * **Reversed S2** (more common in exams) is seen in: LBBB, Aortic Stenosis, and HOCM. * **Wide Fixed Split S2:** Pathognomonic for Atrial Septal Defect (ASD). * **Soft S1:** Seen in First-degree Heart Block and Mitral Regurgitation.

Q: A 34-year-old male with a history of palpitations presents to the emergency department with a pulse rate of 156/min and a BP of 70/40 mm Hg. The emergency crew has attempted vagal maneuvers and adenosine, to which the rhythm is refractory. What is the next step?

DC shock. ### Explanation The core principle in managing any tachyarrhythmia is assessing **hemodynamic stability**. According to ACLS guidelines, the presence of "red flag" signs—such as hypotension (BP 70/40 mm Hg), altered mental status, signs of shock, ischemic chest pain, or acute heart failure—mandates immediate **Synchronized Cardioversion (DC Shock)** [2]. **Why DC Shock is correct:** In this patient, the BP of 70/40 mm Hg indicates hemodynamic instability. While vagal maneuvers and adenosine are first-line for stable Supraventricular Tachycardia (SVT), they should not delay definitive electrical therapy in an unstable patient [2]. Synchronized cardioversion is the treatment of choice to rapidly restore cardiac output and prevent progression to cardiac arrest. **Why other options are incorrect:** * **A. Repeat Adenosine:** Adenosine is used for stable narrow-complex tachycardias. In an unstable patient, repeating a drug that has already failed is a waste of critical time. * **B. Amiodarone:** This is an anti-arrhythmic used for stable Ventricular Tachycardia or as an adjunct in refractory cases. It is not the primary treatment for unstable patients [4]. * **D. Adrenaline:** This is used in pulseless arrest (VF/pVT/Asystole/PEA) or profound anaphylaxis/sepsis, not as a rhythm controller for tachycardia with a pulse [1]. ### High-Yield Clinical Pearls for NEET-PG: * **Unstable + Pulse:** Synchronized Cardioversion [2]. * **Unstable + No Pulse:** Defibrillation (Unsynchronized) [1]. * **Stable Narrow Complex (SVT):** Vagal maneuvers → Adenosine (6mg → 12mg). * **Stable Wide Complex (VT):** Amiodarone or Procainamide [3]. * **Adenosine Contraindication:** Avoid in patients with asthma (can cause bronchospasm) or WPW syndrome with Atrial Fibrillation.

Q: Which electrolyte imbalance is classically associated with a "tombstone" P wave on an ECG?

Hypermagnesemia. The correct answer is **Hypermagnesemia**. **1. Why Hypermagnesemia is Correct:** Magnesium acts as a natural calcium channel blocker and a potent depressant of the cardiac conduction system [2]. While mild elevations are often asymptomatic, severe hypermagnesemia (typically >10 mEq/L) leads to significant electrophysiological changes. The "tombstone" P wave refers to a **broad, tall, and peaked P wave** (not to be confused with "tombstone ST elevation" seen in MI [3]). As magnesium levels rise further, the P wave eventually flattens and disappears, the PR interval prolongs, and the QRS complex widens, potentially leading to complete heart block or asystole. **2. Why the Other Options are Incorrect:** * **Hypomagnesemia:** Classically associated with a prolonged QT interval, flattened T waves, and the development of **Torsades de Pointes** [4]. It does not cause peaked P waves. * **Hypernatremia:** Sodium imbalances primarily affect neurological status (osmotic shifts) rather than specific ECG morphologies [1]. ECG changes in hypernatremia are rare and non-specific. * **Hypocalcemia:** The hallmark ECG finding is **prolongation of the QT interval**, specifically due to lengthening of the ST segment. It does not typically affect the P wave morphology. **3. NEET-PG High-Yield Pearls:** * **Hypermagnesemia Clinical Triad:** Loss of deep tendon reflexes (first sign) → Respiratory depression → Cardiac arrest. * **Antidote:** Calcium gluconate (antagonizes the membrane effects of magnesium). * **Differential for Peaked P waves:** * **P-pulmonale:** Tall, peaked P waves in Lead II (>2.5mm) due to Right Atrial Enlargement. * **Hypermagnesemia:** "Tombstone" P waves (broad and peaked). * **Hyperkalemia vs. Hypermagnesemia:** Hyperkalemia causes peaked **T waves** [1] and flattened P waves; Hypermagnesemia can cause peaked **P waves**.

Q: Right axis deviation is seen in all EXCEPT?

Tricuspid atresia. The standard electrical axis of the heart is determined by the bulk of the ventricular muscle mass. In most congenital cyanotic heart diseases that involve right-sided obstruction or volume overload, **Right Axis Deviation (RAD)** is the expected finding. **1. Why Tricuspid Atresia is the Correct Answer:** Tricuspid Atresia is a unique "high-yield" exception in pediatric cardiology. In this condition, the tricuspid valve fails to develop, leading to an obligatory right-to-left shunt at the atrial level and a **hypoplastic (underdeveloped) right ventricle**. Because the left ventricle must handle both systemic and pulmonary venous return, it undergoes compensatory hypertrophy. This combination of **Left Ventricular Hypertrophy (LVH)** and a small right ventricle results in **Left Axis Deviation (LAD)** on ECG. Finding LAD in a cyanotic infant is a classic diagnostic hallmark for Tricuspid Atresia. **2. Analysis of Other Options:** * **Atrial Septal Defect (ASD):** Causes right ventricular volume overload, leading to RAD and RBBB (Right Bundle Branch Block). * **Pulmonary Atresia:** Typically presents with Right Ventricular Hypertrophy (RVH) due to high pressures, resulting in RAD (unless associated with a hypoplastic RV, but standard pulmonary atresia with VSD follows the RAD pattern). * **Ventricular Septal Defect (VSD):** Large VSDs eventually lead to pulmonary hypertension and RVH (Eisenmenger syndrome), causing RAD. **Clinical Pearls for NEET-PG:** * **Cyanotic Heart Disease + LAD:** Think **Tricuspid Atresia** or **AV Canal Defect (Endocardial Cushion Defect)**. * **ASD Primum vs. Secundum:** ASD primum shows LAD, while ASD secundum (the most common type) shows RAD. * **RAD Criteria:** QRS axis > +90°. Common causes include RVH, Lateral MI, and Left Posterior Fascicular Block (LPFB).

Question 1

On an ECG tracing, the presence of right atrial hypertrophy is suggested by which of the following?

Accepted Answer

Tall spiky P wave

Answer

Widened P wave

Answer

Prolonged P-R interval

Answer

Increased P-Q segment

Question 2

Reasons for preference of internal jugular vein over external jugular vein for measurement of JVP include all except?

Accepted Answer

Increased sympathetic activity in IJV

Answer

IJV is in direct continuation with the right atrium

Answer

EJV passes through more facial planes

Answer

Prominent valves at the proximal portion of EJV

Question 3

A 60-year-old patient presents with recurrent TIA episodes. Echocardiography shows the candle flame sign. What is the probable etiology?

Accepted Answer

Rheumatic fever during youth

Answer

Senile calcification of the heart valve

Answer

Long-standing undiagnosed hypertension

Answer

Undiagnosed congenital condition

Question 4

Bradycardia is a feature of which type of myocardial infarction?

Accepted Answer

Inferior wall MI

Answer

Anterospatial MI

Answer

Lateral wall MI

Answer

Posterior wall MI

Question 5

Hydrostatic Pulmonary edema with fluid in alveoli is usually seen when PCWP is?

Accepted Answer

25mmHg

Answer

>6mmHg

Answer

0mmHg

Answer

15mmHg

Question 6

Reverse splitting of the first heart sound is heard in which condition?

Accepted Answer

Left Bundle Branch Block (LBBB)

Answer

Right Bundle Branch Block (RBBB)

Answer

Tricuspid stenosis

Answer

Aortic Regurgitation (AR)

Question 7

A 34-year-old male with a history of palpitations presents to the emergency department with a pulse rate of 156/min and a BP of 70/40 mm Hg. The emergency crew has attempted vagal maneuvers and adenosine, to which the rhythm is refractory. What is the next step?

Accepted Answer

DC shock

Answer

Repeat adenosine

Answer

Amiodarone

Answer

Adrenaline

Question 8

According to revised guidelines, which of the following drugs is not recommended in cardiac arrest?

Accepted Answer

Atropine

Answer

Adrenaline

Answer

Amiodarone

Answer

Vasopressin

Question 9

Which electrolyte imbalance is classically associated with a "tombstone" P wave on an ECG?

Accepted Answer

Hypermagnesemia

Answer

Hypomagnesemia

Answer

Hypernatremia

Answer

Hypocalcemia

Question 10

Right axis deviation is seen in all EXCEPT?

Accepted Answer

Tricuspid atresia

Answer

Ventricular septal defect (VSD)

Answer

Pulmonary atresia

Answer

Atrial septal defect (ASD)

Cardiology — MCQs

Cardiology — MCQs

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