Cardiology Practice Questions

Q: Prolonged QT interval is not seen in which of the following conditions?

Hypercalcemia. **Explanation:** The QT interval on an ECG represents the total time for ventricular depolarization and repolarization. It is primarily influenced by the duration of the action potential. **Why Hypercalcemia is the correct answer:** In **Hypercalcemia**, the increased extracellular calcium levels shorten the phase 2 (plateau phase) of the cardiac action potential. This leads to faster repolarization, which manifests on the ECG as a **shortened QT interval**. In severe cases, the ST segment may be completely absent, with the T wave starting immediately after the QRS complex. **Analysis of incorrect options (Conditions that prolong QT):** * **Hypocalcemia (B):** Low calcium levels prolong phase 2 of the action potential, leading to a lengthened ST segment and a **prolonged QT interval**. * **Hypokalemia (A):** Low potassium levels delay repolarization and often lead to the appearance of prominent **U waves** [1]. While the "true" QT may be normal, the fusion of the T and U waves creates a "QU interval," which is clinically interpreted as a prolonged QT. * **Hypomagnesemia (C):** Magnesium is a cofactor for the Na+/K+-ATPase pump. Its deficiency impairs repolarization and is frequently associated with both hypokalemia and hypocalcemia, collectively leading to QT prolongation. **High-Yield Clinical Pearls for NEET-PG:** * **Formula:** The corrected QT (QTc) is calculated using **Bazett’s Formula**: $QTc = QT / \sqrt{RR}$. * **Torsades de Pointes:** Prolonged QT interval is the primary precursor for this life-threatening polymorphic ventricular tachycardia [2]. * **Drug-induced QT prolongation:** Common culprits include Class IA and III antiarrhythmics, Macrolides, Fluoroquinolones, and Antipsychotics (e.g., Haloperidol). * **Congenital Syndromes:** Romano-Ward (autosomal dominant, pure cardiac) and Jervell and Lange-Nielsen (autosomal recessive, associated with sensorineural deafness) [3].

Q: Which of the following heart diseases is the most common cause of sudden death in young athletes?

Hypertrophic cardiomyopathy. ### Explanation **Correct Answer: D. Hypertrophic cardiomyopathy (HCM)** **Why it is correct:** Hypertrophic cardiomyopathy is the most common cause of sudden cardiac death (SCD) in young athletes (typically defined as <35 years) [1]. It is an autosomal dominant genetic disorder characterized by asymmetric septal hypertrophy and myofibrillar disarray [1]. The mechanism of sudden death is usually a **lethal ventricular arrhythmia** (Ventricular Tachycardia or Ventricular Fibrillation) triggered during intense physical exertion [1]. The thickened myocardium, combined with fibrosis and ischemia, creates a substrate for these re-entrant arrhythmias [2]. **Why the other options are incorrect:** * **A. Aortic Stenosis:** While congenital bicuspid aortic valve can lead to stenosis and SCD in young individuals, it is significantly less common than HCM in the athletic population [1]. * **B & C. Mitral and Aortic Regurgitation:** Chronic valvular regurgitant lesions generally lead to progressive heart failure over years rather than sudden, unexpected death in an otherwise asymptomatic young athlete. **High-Yield Clinical Pearls for NEET-PG:** * **Murmur Dynamics:** The systolic murmur of HCM **increases** with Valsalva and standing (decreased preload) and **decreases** with squatting or handgrip (increased preload/afterload). This is a classic "opposite" behavior compared to most other murmurs. * **EKG Findings:** Look for "dagger-like" Q waves in lateral (I, aVL, V5-V6) and inferior leads. * **Management:** Beta-blockers are the first-line medical therapy. For those at high risk of SCD (e.g., history of syncope, massive hypertrophy >30mm), an **Implantable Cardioverter Defibrillator (ICD)** is the treatment of choice. * **Note:** In athletes >35 years, the most common cause of SCD shifts from HCM to **Coronary Artery Disease**.

Q: A patient presents with recent onset of breathlessness. An ECG is taken. What is the diagnosis?

Multifocal atrial tachycardia (MAT). ***Multifocal atrial tachycardia (MAT)*** - Characterized by **≥3 different P-wave morphologies**, **variable PR intervals**, **variable RR intervals**, and **heart rate >100 bpm** with irregular rhythm. - Commonly associated with **COPD**, **hypoxemia**, and **electrolyte imbalances**, which can present with breathlessness as the primary symptom. *Atrial fibrillation (AF)* - Shows **absent P waves** with **fibrillatory waves** and **irregularly irregular rhythm**, not multiple distinct P-wave morphologies. - While it can cause breathlessness, the ECG pattern is distinctly different from MAT with its characteristic fibrillatory baseline. *Paroxysmal supraventricular tachycardia (PSVT)* - Presents with **regular rhythm** and **retrograde P waves** (often hidden in QRS or appearing after QRS). - Typically has a **regular RR interval** and sudden onset/termination, contrasting with MAT's irregular pattern. *Acute myocardial infarction (AMI)* - Primary ECG findings include **ST-segment elevation/depression**, **T-wave inversions**, and **pathological Q waves**. - While AMI can cause arrhythmias, the question focuses on rhythm diagnosis rather than **ischemic changes** typical of AMI.

Q: What is characteristic of unstable angina?

The levels of cardiac markers remain unchanged.. ### Explanation The core distinction between **Unstable Angina (UA)** and **Non-ST Elevation Myocardial Infarction (NSTEMI)** lies in the presence or absence of myocardial necrosis. Both conditions fall under the spectrum of Acute Coronary Syndrome (ACS) and may present with similar clinical symptoms (chest pain at rest) and ECG changes (ST-depression or T-wave inversion) [1]. **1. Why the Correct Answer is Right:** In Unstable Angina, there is transient or sub-total occlusion of a coronary artery leading to myocardial ischemia, but the ischemia is not severe or prolonged enough to cause irreversible cell death (necrosis) [2]. Since cardiac biomarkers like Troponin and CK-MB are only released into the bloodstream when the myocardial cell membrane is damaged, **the levels of cardiac markers remain within the normal range in UA.** [1] **2. Why the Incorrect Options are Wrong:** * **Options A, B, and C:** Elevation of **CK-MB**, **Troponin I**, or **Myoglobin** signifies myocardial injury/necrosis. If any of these markers are elevated in the clinical setting of ACS, the diagnosis automatically shifts from Unstable Angina to **Myocardial Infarction (NSTEMI or STEMI)** [1]. **3. NEET-PG Clinical Pearls:** * **Troponins (T and I):** These are the most sensitive and specific markers for cardiac injury. They begin to rise 3–6 hours after injury and can remain elevated for 7–14 days. * **CK-MB:** Useful for detecting **re-infarction** because it returns to baseline quickly (within 48–72 hours). * **Myoglobin:** The earliest marker to rise (1–2 hours), but it lacks specificity for cardiac muscle. * **Braunwald Classification:** Used to grade the severity of Unstable Angina based on the clinical presentation and intensity of treatment. * **Rule of Thumb:** UA = Ischemia (Normal Markers); NSTEMI = Necrosis (Elevated Markers, no ST-elevation); STEMI = Necrosis (Elevated Markers + ST-elevation).

Q: A 40-year-old male with a tense personality, who suffered from attacks of chest pain diagnosed as angina pectoris, presents with a resting heart rate of 96/min and blood pressure of 170/104 mm Hg. His blood sugar level and lipid profile are normal. Which antihypertensive medication is most suitable for initial therapy in this case?

Atenolol. **Explanation:** The patient presents with a triad of **Hypertension (170/104 mm Hg)**, **Tachycardia (96/min)**, and **Angina Pectoris**, likely exacerbated by a "tense personality" (suggestive of high sympathetic tone). **Why Atenolol is the Correct Choice:** Beta-blockers like **Atenolol** are the drugs of choice in this scenario because they address all three components of the patient's presentation: 1. **Antihypertensive effect:** They reduce blood pressure by decreasing cardiac output and inhibiting renin release. 2. **Anti-anginal effect:** They decrease myocardial oxygen demand by reducing heart rate and contractility. 3. **Negative Chronotropy:** They effectively control the resting tachycardia. In patients with co-existing hypertension and stable angina, beta-blockers are considered first-line therapy. **Why Other Options are Incorrect:** * **Nifedipine (Option A):** As a short-acting dihydropyridine, it can cause reflex tachycardia due to rapid vasodilation, which would worsen the patient's existing tachycardia and potentially precipitate an anginal attack. * **Hydrochlorothiazide (Option B):** While an effective antihypertensive, it has no direct benefit for angina or heart rate control. * **Methyldopa (Option D):** Primarily used in pregnancy-induced hypertension; it is not a first-line agent for essential hypertension with angina and often causes sedation. **NEET-PG High-Yield Pearls:** * **Beta-blockers** are the first-line treatment for chronic stable angina. * **Cardioselective Beta-blockers (M-A-N-B-E-A-T):** Metoprolol, Atenolol, Nebivolol, Bisoprolol, Esmolol, Acebutolol, Talinolol. * **Avoid Beta-blockers** in patients with Asthma/COPD, Heart Block, or Prinzmetal Angina (where they can cause coronary vasospasm due to unopposed alpha-action).

Q: In ECG leads II, III, and aVF, abnormalities are noted. Which of the following vessels is most likely blocked?

Right coronary artery. **Explanation:** The ECG leads **II, III, and aVF** are known as the **inferior leads**. They look at the diaphragmatic (inferior) surface of the heart. In approximately 80-85% of individuals (right-dominant circulation), the **Right Coronary Artery (RCA)** gives rise to the Posterior Descending Artery (PDA), which supplies the inferior wall of the left ventricle. Therefore, ST-elevation or Q-waves in these leads typically signify an **Inferior Wall Myocardial Infarction (IWMI)** caused by an RCA occlusion [1]. **Analysis of Options:** * **Right Coronary Artery (Correct):** As the primary vessel supplying the inferior wall in the majority of the population, its blockage leads to changes in leads II, III, and aVF [1]. * **Left Coronary Artery (LCA):** This is the main trunk. A proximal occlusion here would typically cause massive anterolateral infarction (leads V1–V6, I, aVL) and is often fatal. * **Left Anterior Descending (LAD):** Known as the "widow maker," it supplies the anterior wall and septum. Blockage results in changes in leads **V1 to V4** [1]. * **Right Circumflex Artery:** This is a distractor. The **Left Circumflex (LCx)** artery supplies the lateral wall (leads I, aVL, V5, V6). In "left-dominant" individuals (10%), the LCx may supply the inferior wall, but the RCA remains the most common answer for exams. **High-Yield Clinical Pearls for NEET-PG:** * **Right Ventricular Infarction:** About 40% of IWMIs involve the right ventricle. Always check **Lead V4R**; if ST-elevation is present, avoid nitrates (due to preload dependence). * **Bradycardia:** The RCA supplies the SA node (60%) and AV node (90%). Thus, IWMI is frequently associated with sinus bradycardia or AV blocks. * **Lead III > Lead II:** If ST-elevation in lead III is greater than in lead II, it highly suggests RCA over LCx involvement [1].

Q: Cardiomyopathy may be seen in all of the following conditions except?

Alkaptonuria. **Explanation:** The correct answer is **Alkaptonuria**. While Alkaptonuria is a metabolic disorder (deficiency of homogentisate 1,2-dioxygenase), its primary cardiovascular manifestation is **valvular heart disease**—specifically calcific aortic stenosis—rather than cardiomyopathy. The deposition of homogentisic acid (ochronosis) leads to inflammation and calcification of the heart valves and coronary arteries, but it does not typically involve the myocardium to cause cardiomyopathy. **Analysis of other options:** * **Duchenne Muscular Dystrophy (DMD):** This is a classic cause of **Dilated Cardiomyopathy (DCM)** [1]. The absence of dystrophin leads to progressive fibrosis of the myocardium, often involving the posterolateral wall of the left ventricle. * **Friedreich's Ataxia:** This neurodegenerative disorder is highly associated with **Hypertrophic Cardiomyopathy (HCM)** [1]. Up to 90% of patients develop cardiac involvement, which is the most common cause of death in these individuals. * **Type II Glycogen Storage Disease (Pompe Disease):** This lysosomal storage disorder (acid alpha-glucosidase deficiency) causes massive accumulation of glycogen in the heart, leading to severe **Hypertrophic Cardiomyopathy** in the infantile-onset form [1]. **NEET-PG High-Yield Pearls:** * **Pompe Disease:** Look for "massive cardiomegaly" and "short PR interval" on ECG in an infant. * **Friedreich's Ataxia:** Associated with trinucleotide repeat (GAA) on Chromosome 9; cardiac involvement is usually concentric hypertrophy [1]. * **Alkaptonuria:** Key features include dark urine on standing, ochronotic pigmentation of the sclera/ear cartilage, and disabling arthritis of large joints. Remember: **Valves, not Myocardium.**

Q: Angiotensin converting enzyme inhibitors are not used in congestive heart failure resulting from which of the following conditions?

Aortic stenosis. **Explanation:** In **Aortic Stenosis (AS)**, there is a fixed mechanical obstruction to the left ventricular outflow. ACE inhibitors (ACEIs) are potent veno- and arteriodilators. By reducing systemic vascular resistance (afterload), ACEIs can cause a significant drop in blood pressure. Because the cardiac output in severe AS is "fixed" by the narrowed valve, the heart cannot increase output to compensate for this peripheral vasodilation, leading to severe hypotension, syncope, and reduced coronary perfusion. Therefore, ACEIs are generally contraindicated in severe AS. **Analysis of Other Options:** * **Mitral Stenosis:** While caution is needed, ACEIs are not strictly contraindicated. However, they are less effective here because the primary issue is filling the left ventricle, not afterload. * **Aortic Regurgitation (AR):** ACEIs are actually **beneficial** in chronic AR. By reducing afterload, they decrease the resistance against which the heart pumps, thereby reducing the volume of blood that leaks back into the ventricle. * **Alcoholic Cardiomyopathy:** This is a form of dilated cardiomyopathy. ACEIs are the **gold standard** treatment as they prevent ventricular remodeling and reduce mortality. **Clinical Pearls for NEET-PG:** * **Dynamic vs. Fixed Obstruction:** ACEIs are contraindicated in **Fixed** obstructions (Aortic Stenosis, Coarctation of Aorta) and **Dynamic** obstructions (HOCM). * **Bilateral Renal Artery Stenosis:** Another absolute contraindication for ACEIs due to the risk of acute renal failure. * **Teratogenicity:** ACEIs are contraindicated in pregnancy (cause fetal renal dysgenesis). * **Drug of Choice:** ACEIs are the first-line agents for CHF with reduced ejection fraction (HFrEF) and diabetic nephropathy.

Question 1

A 16-year-old male is referred for a physical examination before joining the football team. His elder brother died suddenly during football practice; no autopsy was performed. The patient has a loud systolic murmur on chest auscultation. Which of the following findings is inconsistent with hypertrophic cardiomyopathy?

Accepted Answer

Increase in murmur intensity during Valsalva maneuver or standing

Answer

A crescendo-decrescendo systolic murmur

Answer

Murmur radiating to the neck

Answer

Brisk carotid upstroke

Question 2

Prolonged QT interval is not seen in which of the following conditions?

Accepted Answer

Hypercalcemia

Answer

Hypokalemia

Answer

Hypocalcemia

Answer

Hypomagnesemia

Question 3

An asymptomatic 19-year-old female student presents for routine follow-up. Echocardiogram shows congenital mitral regurgitation. What are the most typical clinical and auscultation findings?

Accepted Answer

Soft S1 and holosystolic murmur radiating from the apex to the axilla

Answer

Early and midsystolic murmur, pulmonary edema, and elevated JVP

Answer

Diminished S1

Answer

Clear lungs and elevated JVP

Question 4

Which of the following heart diseases is the most common cause of sudden death in young athletes?

Accepted Answer

Hypertrophic cardiomyopathy

Answer

Aortic stenosis

Answer

Mitral regurgitation

Answer

Aortic regurgitation

Question 5

A patient presents with recent onset of breathlessness. An ECG is taken. What is the diagnosis?

Accepted Answer

Multifocal atrial tachycardia (MAT)

Answer

Atrial fibrillation (AF)

Answer

Paroxysmal supraventricular tachycardia (PSVT)

Answer

Acute myocardial infarction (AMI)

Question 6

What is characteristic of unstable angina?

Accepted Answer

The levels of cardiac markers remain unchanged.

Answer

CK-MB is elevated

Answer

Troponin I is elevated

Answer

Myoglobin is elevated

Question 7

A 40-year-old male with a tense personality, who suffered from attacks of chest pain diagnosed as angina pectoris, presents with a resting heart rate of 96/min and blood pressure of 170/104 mm Hg. His blood sugar level and lipid profile are normal. Which antihypertensive medication is most suitable for initial therapy in this case?

Accepted Answer

Atenolol

Answer

Nifedipine

Answer

Hydrochlorothiazide

Answer

Methyldopa

Question 8

In ECG leads II, III, and aVF, abnormalities are noted. Which of the following vessels is most likely blocked?

Accepted Answer

Right coronary artery

Answer

Left coronary artery

Answer

Left anterior descending artery

Answer

Right circumflex artery

Question 9

Cardiomyopathy may be seen in all of the following conditions except?

Accepted Answer

Alkaptonuria

Answer

Duchenne muscular dystrophy

Answer

Friedreich's ataxia

Answer

Type II glycogen storage disease

Question 10

Angiotensin converting enzyme inhibitors are not used in congestive heart failure resulting from which of the following conditions?

Accepted Answer

Aortic stenosis

Answer

Mitral stenosis

Answer

Aortic regurgitation

Answer

Alcoholic cardiomyopathy

Cardiology — MCQs

Cardiology — MCQs

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