Cardiology — MCQs

A patient presents with confusion, altered mental status, and unusual behavior. On examination, CNS features such as disorientation and lethargy are noted. Laboratory results reveal a urine osmolality of 1000 mOsm/kg and a plasma osmolality of 250 mOsm/kg. What is the most likely electrolyte imbalance?

Q59

A patient presents with breathing difficulty and generalized weakness. On auscultation, a middiastolic murmur with a prominent "a" wave is observed. What is the most likely diagnosis?

Q60

A patient presents with breathlessness and wheezing. Absolute eosinophil count is 500 cells/ $\mu \mathrm{L}$. Chest X-ray shows a miliary pattern. What is the most likely diagnosis?

Cardiology US Medical PG Practice Questions and MCQs

Question 51: In Type 1 Diabetes Mellitus (DM) stage 3 beta cell destruction, which of the following is the most likely presentation?

A. Dysglycemic symptomatic
B. Normoglycemic symptomatic
C. Dysglycemic asymptomatic
D. Hyperglycemia symptomatic (Correct Answer)
E. Normoglycemic asymptomatic

Explanation: ***Hyperglycemia symptomatic*** - **Type 1 DM stage 3** is characterized by sufficient **beta-cell destruction** to cause overt hyperglycemia. - This level of hyperglycemia typically leads to classic symptoms such as **polyuria, polydipsia, and weight loss**. *Dysglycemic symptomatic* - **Dysglycemic** refers to abnormal blood sugar levels, but this term is too broad and doesn't specify the degree or symptomatic nature as precisely as **hyperglycemia symptomatic**. - While patients are symptomatic, the primary issue is **hyperglycemia**, making that a more specific and accurate description. *Normoglycemic symptomatic* - **Normoglycemic** implies normal blood sugar levels, which is inconsistent with **Type 1 DM stage 3** where significant beta-cell destruction has occurred. - This stage is defined by definite hyperglycemia, so a patient cannot be symptomatic while having normal glucose levels due to the disease. *Dysglycemic asymptomatic* - While there is **dysglycemia**, **asymptomatic presentation** is more characteristic of earlier stages (Type 1 DM stage 2), where hyperglycemia is present but not yet severe enough to cause overt symptoms. - In **stage 3**, beta-cell destruction is substantial, leading to glucose levels that are high enough to cause noticeable symptoms. *Normoglycemic asymptomatic* - **Normoglycemic asymptomatic** describes **Type 1 DM stage 1**, where autoimmunity is present but beta-cell destruction has not yet progressed enough to affect glucose levels. - This is the earliest stage of Type 1 DM, well before the overt hyperglycemia seen in stage 3.

Question 52: A young patient in an endemic area presents with pleural fluid showing LDH level greater than 0.6 times the serum LDH, protein level greater than 0.5 times the serum protein, and lymphocytic predominance. What is the most likely diagnosis?

A. Tuberculosis (Correct Answer)
B. Heart failure
C. Hepatic failure
D. Renal failure
E. Malignancy

Explanation: ***Tuberculosis*** - The patient's presentation with **exudative pleural fluid** (LDH > 0.6 times serum LDH, protein > 0.5 times serum protein) in an **endemic area** strongly suggests tuberculosis. - The **lymphocytic predominance** in the pleural fluid is a hallmark characteristic of tuberculous pleurisy. - **Young age** and **endemic area** further support TB as the most likely diagnosis. *Heart failure* - Pleural effusions due to heart failure are typically **transudative**, meaning they have low protein and LDH levels. - While heart failure can lead to pleural effusions, the fluid characteristics (exudative, lymphocytic predominance) do not fit this diagnosis. *Hepatic failure* - Pleural effusions in hepatic failure (e.g., due to cirrhosis) are usually **transudative** and result from fluid shifting from the abdomen (hepatic hydrothorax). - The fluid analysis in this scenario (exudative, lymphocytic predominance) is inconsistent with hepatic failure. *Renal failure* - Pleural effusions associated with renal failure (e.g., uremic pleurisy) can be exudative, but they often present with a **neutrophilic predominance** or may be hemorrhagic. - The specific lymphocytic predominance points away from typical renal failure-associated effusions. *Malignancy* - While malignant pleural effusions (lymphoma, metastatic carcinoma) can present with **lymphocytic predominance** and exudative characteristics, the clinical context is crucial. - The patient's **young age** and presentation in an **endemic area for tuberculosis** makes TB far more likely than malignancy. - In endemic areas, TB should be ruled out first before considering malignancy in young patients with lymphocytic pleural effusions.

Question 53: A patient presents with hypotension, hyponatremia, and blackening of the palmar creases. Which of the following conditions is most likely associated with these symptoms?

A. Conn syndrome
B. Cushing's syndrome
C. Primary ACTH deficiency
D. Addison disease (Correct Answer)
E. Sheehan syndrome

Explanation: ***Addison disease*** - **Hypotension**, **hyponatremia**, and **hyperpigmentation** (blackening of palmar creases) are classic symptoms of **primary adrenal insufficiency** or Addison disease, due to deficient cortisol and aldosterone. - The lack of **cortisol** leads to hypotension and fatigue, while the absence of **aldosterone** causes hyponatremia and hyperkalemia. *Conn syndrome* - This condition involves **primary hyperaldosteronism**, typically leading to **hypertension** and **hypokalemia**, which contradicts the patient's symptoms of hypotension and hyponatremia. - Pigmentation changes are not a feature of Conn syndrome. *Cushing's syndrome* - Characterized by **excess cortisol**, leading to symptoms like **hypertension**, **hyperglycemia**, and central obesity, not hypotension or hyperpigmentation. - **Hyponatremia** is also not typical in Cushing's syndrome. *Primary ACTH deficiency* - Also known as **secondary adrenal insufficiency**, this condition results in low cortisol but typically spares aldosterone production, meaning **hyponatremia** and **hyperkalemia** are less common. - **Hyperpigmentation** does not occur in primary ACTH deficiency because ACTH levels are low. *Sheehan syndrome* - This is **postpartum pituitary necrosis** causing panhypopituitarism, which can lead to secondary adrenal insufficiency with hypotension and hyponatremia. - However, **hyperpigmentation does not occur** in Sheehan syndrome because ACTH levels are low (secondary insufficiency), not elevated as in Addison disease. - The clinical context would typically include a history of postpartum hemorrhage and failure to lactate.

Question 54: A patient presents with wheezing that improves with as-needed use of albuterol. Spirometry shows FEV1 ranging from 70 % to 83 %, and the patient experiences nighttime chest tightening twice a week. What is the most appropriate treatment?

A. Continue with albuterol
B. Replace with salmeterol twice daily
C. Start Tab prednisolone
D. Add an inhaled corticosteroid (Correct Answer)
E. Add a leukotriene modifier

Explanation: ***Add an inhaled corticosteroid*** * The patient has persistent asthma as evidenced by symptoms occurring twice a week (nighttime chest tightening), and **FEV1 variability** despite current albuterol use. * Adding a **low-dose inhaled corticosteroid** is the recommended *first-line controller treatment* for persistent asthma to reduce inflammation and prevent exacerbations per **GINA guidelines**. *Continue with albuterol* * Continuing albuterol alone is insufficient for persistent asthma, as it only provides **symptomatic relief** and does not address the underlying inflammation. * This approach would lead to continued symptoms and potential **asthma exacerbations**. *Replace with salmeterol twice daily* * Salmeterol is a **long-acting beta-agonist (LABA)**, and while it provides prolonged bronchodilation, it should never be used as monotherapy in asthma due to the risk of severe exacerbations. * LABAs should always be prescribed in combination with an **inhaled corticosteroid**. *Start Tab prednisolone* * **Oral prednisolone** is a systemic corticosteroid typically reserved for **severe asthma exacerbations** or for patients whose symptoms are not controlled by high-dose inhaled corticosteroids and other controller medications. * It carries more significant **side effects** with long-term use compared to inhaled corticosteroids. *Add a leukotriene modifier* * While **leukotriene receptor antagonists** (e.g., montelukast) can be used as alternative controller therapy for mild persistent asthma, they are considered **less effective** than inhaled corticosteroids. * They are typically reserved as an alternative for patients who cannot use or tolerate inhaled corticosteroids, or as **add-on therapy** in more severe cases.

Question 55: A 60-year-old lady presents with shortness of breath (SOB) and episodes of angina pectoris. Work-up reveals aortic stenosis. Which of the following is the most likely reason behind these chest pain episodes?

A. Increased pressure in aorta
B. Decreased pressure in aorta
C. Increased oxygen consumption in the heart (Correct Answer)
D. Increase in volume overload of the heart
E. Decreased coronary blood flow

Explanation: ***Increased oxygen consumption in the heart*** - In **aortic stenosis**, the left ventricle must generate significantly higher pressures to eject blood through the narrowed aortic valve, leading to **left ventricular hypertrophy**. This increased workload significantly raises the **myocardial oxygen demand**. - Angina pectoris occurs when this increased oxygen demand surpasses the oxygen supply, leading to **myocardial ischemia**. - This is the **primary mechanism** of angina in aortic stenosis. *Increased pressure in aorta* - While there is **increased pressure within the left ventricle** to overcome the stenotic valve, the pressure in the aorta *distal* to the stenosis is often normal or even slightly reduced due to the obstruction. - Increased aortic pressure itself is not the primary direct cause of angina in aortic stenosis; rather, it's the compensatory ventricular workload. *Decreased pressure in aorta* - A **decreased pressure in the aorta** could actually worsen coronary perfusion, but the primary reason for angina in aortic stenosis is the vastly **increased myocardial demand**, not necessarily a critical drop in aortic pressure. - The elevated left ventricular pressure required to overcome the stenosis is the key factor driving the angina. *Increase in volume overload of the heart* - **Aortic stenosis primarily causes pressure overload**, not volume overload, on the left ventricle due to the obstruction to outflow. - Volume overload typically occurs in conditions like **aortic regurgitation** or **mitral regurgitation**, which have different pathophysiological mechanisms for angina. *Decreased coronary blood flow* - While **decreased coronary perfusion** can be a contributing factor in aortic stenosis (due to reduced aortic pressure and shortened diastolic filling time), it is a **secondary mechanism**. - The **primary cause** of angina in aortic stenosis is the markedly **increased myocardial oxygen demand** from left ventricular hypertrophy and increased workload, rather than a primary reduction in coronary blood flow.

Question 56: A hypertensive patient presents with an irregularly irregular pulse and a loud P2 on auscultation. Which JVP finding is likely to be seen in this patient?

A. Absent a wave (Correct Answer)
B. Cannon a wave
C. Rapid $x$ descent
D. Rapid $y$ descent
E. Prominent v wave

Explanation: ***Absent a wave*** - An **irregularly irregular pulse** and **loud P2** suggest **atrial fibrillation** with **pulmonary hypertension**. In atrial fibrillation, there is chaotic atrial activity, meaning the atria do not contract in a coordinated fashion. - The **"a" wave** on the JVP tracing represents **atrial contraction**. Since the atria are fibrillating and not contracting effectively, the normal "a" wave will be absent. *Cannon a wave* - **Cannon a waves** occur when the **right atrium contracts against a closed tricuspid valve**, such as during **ventricular tachycardia** or **complete heart block** (AV dissociation). - This patient's irregularly irregular pulse suggests **atrial fibrillation**, not a condition typically associated with cannon a waves. *Rapid $x$ descent* - A **rapid x descent** primarily reflects **atrial relaxation** and **right ventricular systole**, which pulls the tricuspid annulus downwards. - While a rapid x descent can be seen in various conditions, it is not the most specific JVP finding for the described clinical picture, which points strongly to absent atrial contraction. *Rapid $y$ descent* - A **rapid y descent** signifies rapid filling of the right ventricle during early diastole, often associated with a **compliant right ventricle** and unobstructed tricuspid inflow. It can be prominent in conditions like **constrictive pericarditis** or **restrictive cardiomyopathy**. - This finding is not directly or specifically linked to the irregularly irregular pulse and absent atrial contraction seen in atrial fibrillation. *Prominent v wave* - A **prominent v wave** occurs with **tricuspid regurgitation**, where blood regurgitates back into the right atrium during ventricular systole, causing venous distension. - While pulmonary hypertension can eventually lead to right ventricular dysfunction and tricuspid regurgitation, the most characteristic JVP finding for **atrial fibrillation itself** is the **absence of the "a" wave** due to lack of coordinated atrial contraction.

Question 57: 30-year-old male, weighing 70 kg , presents with a serum sodium level of $120 \mathrm{mEq} / \mathrm{L}$. Calculate the total sodium deficit.

A. 630 mEq
B. 280 mEq
C. 420 mEq
D. 840 mEq (Correct Answer)
E. 1260 mEq

Explanation: ***840 mEq*** - The formula for calculating **total sodium deficit** is: **(Desired Na - Actual Na) × Total Body Water (TBW)**. - In a male, TBW is approximately **60% of body weight**. For a 70 kg male, **TBW = 0.6 × 70 kg = 42 L**. - With a desired sodium of **140 mEq/L** (normal) and actual sodium of **120 mEq/L**, the total deficit is: - **(140 - 120) × 42 = 20 × 42 = 840 mEq** - This represents the **complete calculated sodium deficit** needed to restore serum sodium to normal levels. - **Note:** In clinical practice, this entire deficit is NOT replaced rapidly. Typically, only **6-12 mEq/L increase per 24 hours** is recommended to prevent **osmotic demyelination syndrome**, but the question asks for the total calculated deficit. *630 mEq* - This value represents a **partial correction target**, corresponding to raising serum sodium to approximately **135 mEq/L** instead of 140 mEq/L: (135 - 120) × 42 = 630 mEq. - Alternatively, it equals about **75% of the total deficit** (840 × 0.75 = 630). - While this may reflect a practical clinical target, it does not answer the question which asks for the **total deficit**. *420 mEq* - This corresponds to raising serum sodium by **10 mEq/L** (10 × 42 = 420 mEq). - This represents the **maximum recommended increase in the first 24 hours** to prevent complications. - It is a safe initial correction amount but not the total calculated deficit. *280 mEq* - This represents an even smaller increment, roughly equivalent to raising serum sodium by **6-7 mEq/L**. - This would be an **ultra-conservative initial correction** for chronic hyponatremia. - It significantly underestimates the total sodium deficit. *1260 mEq* - This is an **overestimation** that might result from incorrectly using 100% body weight as TBW instead of 60%: (140 - 120) × 70 = 1400 mEq (close to this range). - Or from miscalculation using wrong formula components. - This exceeds the actual total sodium deficit.

Question 58: A patient presents with confusion, altered mental status, and unusual behavior. On examination, CNS features such as disorientation and lethargy are noted. Laboratory results reveal a urine osmolality of 1000 mOsm/kg and a plasma osmolality of 250 mOsm/kg. What is the most likely electrolyte imbalance?

A. Hypokalemia
B. Hyperkalemia
C. Hyponatremia (Correct Answer)
D. Hypernatremia
E. Hypercalcemia

Explanation: ***Hyponatremia*** - The **low plasma osmolality** (250 mOsm/kg) combined with a **high urine osmolality** (1000 mOsm/kg) indicates that the kidneys are inappropriately concentrating urine despite diluted plasma, a hallmark finding in euvolemic hyponatremia. - **Confusion**, **altered mental status**, and **unusual behavior** are classic neurological symptoms associated with hyponatremia, particularly when it develops acutely or severely. *Hypokalemia* - **Hypokalemia** is characterized by low serum potassium and can cause muscle weakness, arrhythmias, and fatigue, but it does not directly explain the given plasma and urine osmolality findings. - The neurological symptoms described are not typical primary manifestations of hypokalemia. *Hyperkalemia* - **Hyperkalemia** involves high serum potassium, commonly leading to cardiac arrhythmias and muscle weakness. - The provided **osmolality values** are not consistent with a primary diagnosis of hyperkalemia. *Hypernatremia* - **Hypernatremia** is defined by high serum sodium and would present with **high plasma osmolality**, which contradicts the given plasma osmolality of 250 mOsm/kg. - While it can cause neurological symptoms, the osmolality findings rule it out. *Hypercalcemia* - **Hypercalcemia** can present with neurological symptoms including confusion and lethargy ("stones, bones, groans, and psychiatric overtones"). - However, hypercalcemia does not produce the characteristic **low plasma osmolality with high urine osmolality** pattern seen in this case.

Question 59: A patient presents with breathing difficulty and generalized weakness. On auscultation, a middiastolic murmur with a prominent "a" wave is observed. What is the most likely diagnosis?

A. Mitral Regurgitation (MR)
B. Mitral Stenosis (MS)
C. Tricuspid Regurgitation (TR)
D. Tricuspid Stenosis (TS) (Correct Answer)
E. Pulmonary Stenosis (PS)

Explanation: ***Tricuspid Stenosis (TS)*** - A **middiastolic murmur** in the tricuspid area (usually left lower sternal border) along with a **prominent "a" wave** (due to increased right atrial pressure against a stenotic tricuspid valve) is pathognomonic for tricuspid stenosis. - The symptoms of **breathing difficulty** and **generalized weakness** can arise from reduced cardiac output and venous congestion characteristic of TS. *Mitral Regurgitation (MR)* - MR typically presents with a **holosystolic murmur** best heard at the apex and radiating to the axilla. - It does not characteristically produce a middiastolic murmur or a prominent "a" wave. *Mitral Stenosis (MS)* - MS causes a **diastolic rumble** with an **opening snap**, best heard at the apex, but it is not typically associated with a pronounced "a" wave in the jugular venous pulse unless there's associated pulmonary hypertension and right heart strain. - The murmur is usually localized to the apex, whereas tricuspid murmurs are typically heard from the lower left sternal border. *Tricuspid Regurgitation (TR)* - TR is characterized by a **holosystolic murmur** that increases with inspiration, heard at the left lower sternal border. - It typically causes a prominent **"v" wave** in the jugular venous pulse due to regurgitant flow into the right atrium, not a prominent "a" wave. *Pulmonary Stenosis (PS)* - PS presents with a **systolic ejection murmur** at the left upper sternal border (pulmonic area), not a diastolic murmur. - While it can cause right heart strain, it does not produce the characteristic middiastolic murmur or prominent "a" wave seen in tricuspid stenosis.

Question 60: A patient presents with breathlessness and wheezing. Absolute eosinophil count is 500 cells/ $\mu \mathrm{L}$. Chest X-ray shows a miliary pattern. What is the most likely diagnosis?

A. Tropical pulmonary eosinophilia (Correct Answer)
B. Bronchial asthma
C. Miliary Tuberculosis (TB)
D. Hypersensitivity pneumonitis
E. Allergic bronchopulmonary aspergillosis (ABPA)

Explanation: ***Tropical pulmonary eosinophilia*** - This condition is characterized by **eosinophilia** (absolute eosinophil count >500 cells/µL), **respiratory symptoms** such as breathlessness and wheezing, and a **miliary pattern** on chest X-ray, all consistent with the patient's presentation. - It results from a **hypersensitivity reaction** to microfilariae from Wuchereria bancrofti or Brugia malayi in individuals living in endemic regions. *Bronchial asthma* - While bronchial asthma can cause **breathlessness** and **wheezing**, a miliary pattern on chest X-ray is **not typical**, nor is an eosinophil count of 500 cells/µL, though eosinophilia can occur. - Asthma is primarily a disease of reversible airway obstruction, often triggered by **allergens** or irritants. *Miliary Tuberculosis (TB)* - **Miliary TB** would present with a miliary pattern on chest X-ray and breathlessness, but it is typically associated with **low or normal eosinophil counts**, and wheezing is less common. - Fever, night sweats, and weight loss are also common symptoms of Miliary TB. *Hypersensitivity pneumonitis* - This condition involves inflammation of the lung alveoli due to inhalation of organic dusts or chemicals, causing **breathlessness** and, occasionally, wheezing, but **eosinophilia is not a primary feature**. - Chest X-ray findings can be diverse, but a **miliary pattern** is less specific than for tropical pulmonary eosinophilia. *Allergic bronchopulmonary aspergillosis (ABPA)* - ABPA can present with **eosinophilia**, **wheezing**, and respiratory symptoms, but chest X-ray typically shows **central bronchiectasis** and **fleeting infiltrates** rather than a miliary pattern. - It occurs in patients with asthma or cystic fibrosis and is characterized by **hypersensitivity to Aspergillus fumigatus**.

Practice by Chapter

Hypertension diagnosis and management

Practice Questions

Stable coronary artery disease

Practice Questions

Peripheral arterial disease

Practice Questions

Aortic diseases

Practice Questions

Valvular heart disease

Practice Questions

Pericardial diseases

Practice Questions

Adult congenital heart disease

Practice Questions

Cardiac tumors

Practice Questions

Cardiac manifestations of systemic diseases

Practice Questions

Pre-operative cardiac risk assessment

Practice Questions

Cardiac imaging modalities

Practice Questions

Preventive cardiology

Practice Questions

Cardiac rehabilitation

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Cardiology — MCQs

Cardiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?