Cardiology Practice Questions

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).

Q: A 50-year-old male presented to the ER with new onset chest pain that was progressively increasing in nature and described as tearing pain, persisting for more than 20 minutes. After ECG, the patient was immediately put on thrombolysis therapy. Which vein is accompanied by the artery involved in this case?

Great cardiac vein. The clinical presentation describes a patient with **Acute Coronary Syndrome (ACS)**, specifically a Myocardial Infarction (MI) [3], as evidenced by the decision to perform immediate thrombolysis. In the context of NEET-PG questions, "tearing pain" often hints at aortic dissection; however, the immediate administration of **thrombolysis** based on an ECG confirms the diagnosis of **ST-Elevation Myocardial Infarction (STEMI)** [1][2]. The most commonly involved artery in MI is the **Left Anterior Descending (LAD) artery**, which is the "artery of sudden death." Anatomically, the LAD runs in the anterior interventricular groove. * **Correct Option (A):** The **Great Cardiac Vein** travels alongside the **LAD artery** in the anterior interventricular groove. Therefore, it is the vein accompanying the artery involved in this case. **Why other options are incorrect:** * **B. Small Cardiac Vein:** Accompanies the **Right Marginal Artery** along the lower border of the heart. * **C. Middle Cardiac Vein:** Accompanies the **Posterior Interventricular Artery** (usually a branch of the Right Coronary Artery) in the posterior interventricular groove. * **D. Oblique Vein of Left Atrium (Vein of Marshall):** A small vein on the posterior wall of the left atrium; it does not accompany a major coronary artery involved in STEMI thrombolysis protocols. **High-Yield Clinical Pearls for NEET-PG:** 1. **LAD Artery:** Accompanied by the **Great Cardiac Vein**. 2. **Posterior Interventricular Artery:** Accompanied by the **Middle Cardiac Vein**. 3. **Right Marginal Artery:** Accompanied by the **Small Cardiac Vein**. 4. **Coronary Sinus:** The largest vein of the heart, draining into the Right Atrium. 5. **Thrombolysis Rule:** Only indicated in STEMI (not NSTEMI or Unstable Angina) [1] if PCI cannot be performed within 120 minutes.

Q: In severe aortic stenosis, which of the following is a true finding?

ST segment changes in ECG. Explanation: **Correct Answer: C. ST segment changes in ECG** In severe Aortic Stenosis (AS), the left ventricle (LV) must generate massive pressure to overcome the narrowed valve orifice. This leads to compensatory **Left Ventricular Hypertrophy (LVH)**. On an ECG, this manifests as high-voltage QRS complexes accompanied by **ST-segment depression and T-wave inversion** (the "LV strain pattern"). These changes reflect subendocardial ischemia due to increased myocardial oxygen demand and reduced coronary perfusion pressure, even in the absence of coronary artery disease. **Analysis of Incorrect Options:** * **A. Late systolic ejection click:** Ejection clicks occur in *mild-to-moderate* AS when the valve leaflets are still mobile. In **severe** AS, the valve is heavily calcified and immobile, causing the click to disappear [2]. * **B. Heaving with outward apex beat:** While AS causes a "heaving" (sustained) apex beat due to LVH, the apex is typically **not displaced** outward in pure AS. Displacement occurs only when the heart fails and dilates. * **D. Loud S2:** In severe AS, the aortic component of the second heart sound (A2) is **soft or absent** because the leaflets are too rigid to snap shut [1]. **High-Yield NEET-PG Pearls:** * **Classic Triad of AS:** Dyspnea (most common), Angina, and Syncope (SAD). * **Pulse Finding:** *Pulsus Parvus et Tardus* (small volume, slow-rising pulse). * **Auscultation:** A harsh crescendo-decrescendo systolic murmur [1]. The **later the peak** of the murmur, the more severe the stenosis. * **Reverse Splitting:** Severe AS can cause paradoxical splitting of S2.

Q: Which drug is used in unstable angina to prevent myocardial infarction?

Aspirin. **Explanation:** **Aspirin (Correct Answer):** The primary pathology in unstable angina (UA) is the rupture or erosion of an atherosclerotic plaque, leading to sub-occlusive thrombus formation. Aspirin acts as an irreversible inhibitor of **Cyclooxygenase-1 (COX-1)**, preventing the synthesis of **Thromboxane A2** [1]. This inhibits platelet aggregation and prevents the progression of a partial thrombus to a complete occlusion (ST-Elevation MI) [2]. Clinical trials have proven that Aspirin reduces the risk of myocardial infarction (MI) and death in patients with UA by approximately 50%. **Incorrect Options:** * **Glyceryl trinitrate (GTN):** While GTN is the first-line drug for symptomatic relief of chest pain via venodilation (reducing preload), it **does not** improve mortality or prevent MI. * **Amlodipine:** This is a Calcium Channel Blocker (CCB) used for blood pressure control and vasospastic angina [3]. It does not have anti-platelet properties and is not used as a primary preventive measure for MI in the acute setting [4]. * **Fasudil:** This is a Rho-kinase inhibitor used primarily in the treatment of cerebral vasospasm and pulmonary hypertension; it has no established role in the management of unstable angina. **High-Yield Clinical Pearls for NEET-PG:** * **Dual Antiplatelet Therapy (DAPT):** In UA/NSTEMI, Aspirin is combined with a P2Y12 inhibitor (e.g., Clopidogrel, Ticagrelor) for synergistic effects. * **Loading Dose:** For acute coronary syndromes, the loading dose of Aspirin is **162–325 mg** (non-enteric coated, chewed for faster absorption). * **Contraindication:** Avoid Aspirin in patients with active peptic ulcer disease or known hypersensitivity (Aspirin-exacerbated respiratory disease).

Q: J waves (Osborn waves) on ECG are seen in all of the following conditions EXCEPT:

Hypocalcemia. ***Hypocalcemia*** - Hypocalcemia causes **prolonged QT interval** on ECG, not **J waves (Osborn waves)**. - The primary ECG finding is **QT prolongation** due to delayed ventricular repolarization, which can predispose to **torsades de pointes**. *Hypothermia* - **J waves (Osborn waves)** are classically seen in **hypothermia**, appearing as positive deflections at the **J point** (junction of QRS and ST segment). - The waves become more prominent as body temperature drops below **32°C (90°F)** and are most pronounced in **leads II, V5, and V6**. *Hypercalcemia* - **Hypercalcemia** can cause **J waves** along with **shortened QT intervals** due to accelerated ventricular repolarization. - Other ECG changes include **widened QRS complexes** and potential **bradycardia** in severe cases. *Subarachnoid hemorrhage (SAH)* - **SAH** can produce **J waves** as part of **neurogenic cardiac effects** due to massive **catecholamine release**. - Other ECG abnormalities include **deep T wave inversions**, **QT prolongation**, and various **arrhythmias** due to autonomic dysfunction.

Q: A patient with a moderate ventricular septal defect (VSD) in chronic congestive cardiac failure (CCF) develops clubbing without cyanosis. What is the most likely diagnosis?

Subacute bacterial endocarditis (SABE). ### Explanation The correct diagnosis is **Subacute Bacterial Endocarditis (SABE)**. **1. Why SABE is the Correct Answer:** In a patient with a moderate VSD, the presence of **clubbing without cyanosis** is a classic clinical pointer toward SABE. While clubbing is frequently associated with cyanotic congenital heart diseases (e.g., Tetralogy of Fallot), in acyanotic conditions like VSD, it typically signifies a complication. SABE causes chronic inflammation and the release of growth factors (like PDGF) from platelet-fibrin vegetations, leading to digital clubbing. Since the shunt remains left-to-right, the patient remains acyanotic. **2. Why Other Options are Incorrect:** * **Shunt Reversal (Eisenmenger Syndrome):** This occurs when pulmonary hypertension becomes severe enough to reverse the shunt (right-to-left). While this causes clubbing, it **must** be accompanied by central cyanosis. * **Long-standing Pulmonary Edema:** Chronic congestion leads to dyspnea and rales but does not cause digital clubbing. * **Pulmonary Arterial Hypertension (PAH):** PAH itself does not cause clubbing unless it progresses to shunt reversal (Eisenmenger syndrome), at which point cyanosis would be mandatory. **3. High-Yield Clinical Pearls for NEET-PG:** * **VSD & SABE:** Small to moderate VSDs have a higher risk of SABE than large VSDs because the high-velocity jet creates more turbulence and endocardial damage. * **Clubbing in Cardiology:** Always differentiate between **Cyanotic Clubbing** (TOF, Eisenmenger) and **Acyanotic Clubbing** (SABE, Atrial Myxoma). * **Most Common Site for SABE in VSD:** Vegetations usually form on the **tricuspid valve** or the margins of the defect on the right ventricular side due to the "jet effect." * **Prophylaxis:** Current guidelines do not recommend routine antibiotic prophylaxis for uncomplicated VSDs unless there is a prior history of endocarditis or prosthetic material used in repair.

Q: A 36-year-old female presents with a sensation of fast heart rate, slight dizziness, and vague chest fullness. Blood pressure is 110/70. The following rhythm strip is obtained, which shows?

Supraventricular tachycardia. ***Supraventricular tachycardia*** - Presents as **regular narrow-complex tachycardia** with a rate of **150-250 bpm** and absent or retrograde **P waves**, consistent with SVT. - Clinical presentation of **palpitations**, slight dizziness, and **preserved hemodynamics** (normal BP) is typical for SVT in young patients. *Atrial fibrillation* - Characterized by **irregularly irregular rhythm** with absent P waves and **variable RR intervals**, not a regular tachycardia. - Would show **fibrillatory waves** on ECG rather than the regular narrow-complex pattern seen in SVT. *Atrial flutter* - Shows characteristic **sawtooth flutter waves** at a rate of approximately **300 bpm** with regular **2:1 or 3:1 conduction block**. - Produces a more regular ventricular response but with **visible flutter waves** between QRS complexes, unlike SVT. *Ventricular tachycardia* - Presents as **wide-complex tachycardia** (QRS >120 ms) originating from ventricular tissue, not narrow complex. - Often associated with **hemodynamic compromise** and more severe symptoms than described in this stable patient.

Q: A patient presents 12 hours following a Myocardial infarction. What is the test of choice?

Cardiac troponins. **Explanation:** The diagnosis of acute myocardial infarction (MI) relies on the detection of a rise and/or fall of cardiac biomarkers [3]. **Cardiac Troponins (I and T)** are the "Gold Standard" and the test of choice due to their high sensitivity and superior myocardial specificity [2]. 1. **Why Cardiac Troponins are correct:** Troponins begin to rise within **3–6 hours** of myocardial injury, peak at **12–24 hours**, and remain elevated for 7–14 days. At the 12-hour mark, Troponins are highly sensitive and are the preferred markers for diagnosing both STEMI and NSTEMI [2]. 2. **Why other options are incorrect:** * **Myoglobin:** This is the earliest marker to rise (1–2 hours), but it lacks cardiac specificity (also found in skeletal muscle) and returns to baseline within 24 hours. It is used for early "rule-out" but not for definitive diagnosis. * **Creatine Phosphokinase (CK-MB):** While specific to the heart, it peaks around 24 hours and returns to normal within 48–72 hours [3]. It is primarily used to detect **re-infarction** because of its short half-life compared to Troponin. * **Lactate Dehydrogenase (LDH):** This is a late marker (rises after 24 hours, peaks at 3–4 days). It is now obsolete in acute settings due to poor specificity [1]. **NEET-PG High-Yield Pearls:** * **Earliest marker:** Myoglobin. * **Most specific marker:** Cardiac Troponin I. * **Marker for Re-infarction:** CK-MB. * **Marker for late diagnosis (>7 days):** Troponin T (remains elevated longer than I). * **False positive Troponin:** Can occur in Chronic Kidney Disease (CKD), Pulmonary Embolism, and Sepsis.

Question 1

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

Accepted Answer

Hypermagnesemia

Answer

Hypomagnesemia

Answer

Hypernatremia

Answer

Hypocalcemia

Question 2

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)

Question 3

A 50-year-old male presented to the ER with new onset chest pain that was progressively increasing in nature and described as tearing pain, persisting for more than 20 minutes. After ECG, the patient was immediately put on thrombolysis therapy. Which vein is accompanied by the artery involved in this case?

Accepted Answer

Great cardiac vein

Answer

Small cardiac vein

Answer

Middle cardiac vein

Answer

Oblique vein of left atrium

Question 4

In severe aortic stenosis, which of the following is a true finding?

Accepted Answer

ST segment changes in ECG

Answer

Late systolic ejection click

Answer

Heaving with outward apex beat

Answer

Loud S2

Question 5

Which drug is used in unstable angina to prevent myocardial infarction?

Accepted Answer

Aspirin

Answer

Glyceryl trinitrate (GTN)

Answer

Amlodipine

Answer

Fasudil

Question 6

J waves (Osborn waves) on ECG are seen in all of the following conditions EXCEPT:

Accepted Answer

Hypocalcemia

Answer

Hypothermia

Answer

Hypercalcemia

Answer

Subarachnoid hemorrhage (SAH)

Question 7

A patient with a moderate ventricular septal defect (VSD) in chronic congestive cardiac failure (CCF) develops clubbing without cyanosis. What is the most likely diagnosis?

Accepted Answer

Subacute bacterial endocarditis (SABE)

Answer

Shunt reversal

Answer

Long standing pulmonary edema

Answer

Pulmonary arterial hypertension

Question 8

A 36-year-old female presents with a sensation of fast heart rate, slight dizziness, and vague chest fullness. Blood pressure is 110/70. The following rhythm strip is obtained, which shows?

Accepted Answer

Supraventricular tachycardia

Answer

Atrial fibrillation

Answer

Atrial flutter

Answer

Ventricular tachycardia

Question 9

A patient presents 12 hours following a Myocardial infarction. What is the test of choice?

Accepted Answer

Cardiac troponins

Answer

Lactate dehydrogenase

Answer

Creatinine phosphokinase

Answer

Myoglobin

Question 10

A 37-year-old woman presents with shortness of breath on exertion. She has a past history of rheumatic fever as a child. On cardiac auscultation, there is a loud S1 and a mid-to-late low-pitched diastolic murmur. Which of the following findings is most likely to be seen on the chest X-ray in someone with mitral stenosis?

Accepted Answer

Straightening of the left heart border

Answer

General enlargement of the heart

Answer

Kerley B lines

Answer

Attenuation of pulmonary arteries

Cardiology — MCQs

Cardiology — MCQs

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