Cardiology Practice Questions

Q: Torsades de pointes is seen in all except

Hyponatremia. ***Hyponatremia*** - **Hyponatremia** (low sodium levels) primarily affects neuronal function and can lead to neurological symptoms like seizures and altered mental status [1]. - It does not directly cause **QT prolongation** or **Torsades de Pointes (TdP)**, which are typically associated with electrolyte imbalances affecting cardiac repolarization. *Hypocalcemia* - **Hypocalcemia** (low calcium levels) can prolong the **QT interval** on an electrocardiogram. - Prolongation of the QT interval increases the risk of developing **Torsades de Pointes**, a life-threatening polymorphic ventricular tachycardia [2]. *Hypomagnesemia* - **Hypomagnesemia** (low magnesium levels) is a common cause and aggravator of **Torsades de Pointes**. - Magnesium plays a crucial role in cardiac ion channel function, and its deficiency can lead to significant **QT prolongation** and ventricular arrhythmias. *Hypokalemia* - **Hypokalemia** (low potassium levels) can prolong the **QT interval** and increase the risk of developing ventricular arrhythmias, including **Torsades de Pointes** [1]. - Potassium channels are essential for cardiac repolarization, and their dysfunction due to low potassium can destabilize myocardial electrical activity [1].

Q: Absent P Wave is seen on an ECG in:

Atrial Fibrillation (AF). ***Atrial Fibrillation (AF)*** - In **atrial fibrillation**, the atria beat chaotically and irregularly, leading to the absence of coordinated **atrial depolarization**, thus no distinct P wave is seen [1]. - The ECG characteristically shows an **irregularly irregular rhythm** with narrow QRS complexes and no discernible P waves. *Cor Pulmonale* - Cor pulmonale involves right ventricular hypertrophy and dilation due to lung disease, which can cause peaked **P waves (P pulmonale)** in leads II, III, aVF, indicating right atrial enlargement. - It does not typically lead to the absence of P waves but rather changes in their morphology. *Mitral Stenosis* - **Mitral stenosis** can cause left atrial enlargement, which typically manifests as a broad, notched **P wave (P mitrale)**, especially in lead II, and a prominent negative phase in V1. - P waves are present but altered in appearance due to the increased atrial pressure and volume. *Chronic Obstructive Pulmonary Disease (COPD)* - Patients with **COPD** often show signs of right atrial enlargement, similar to cor pulmonale, resulting in **P pulmonale** on the ECG due to increased pulmonary pressures. - While other ECG changes like low voltage and right axis deviation may be present, the P wave is generally present, though often peaked.

Q: Diagnose the underlying medical disorder based on the ECG changes.

ECG changes due to hypocalcemia. ***ECG changes due to hypocalcemia*** - **Hypocalcemia** characteristically causes a **prolonged QT interval** on the ECG due to delayed repolarization of ventricular myocytes. - This prolongation is primarily due to the lengthening of the **ST segment**, while the T wave itself is usually unchanged. *ECG changes due to hypokalemia* - **Hypokalemia** typically presents with prominent **U waves**, T wave flattening or inversion, and sometimes ST segment depression. - While it can also prolong the QT interval, the primary distinguishing feature is the presence of U waves, which are not mentioned as the main finding. *ECG changes due to hypercalcemia* - **Hypercalcemia** is associated with a **shortened QT interval** on the ECG due to accelerated repolarization. - It can also cause a shortened ST segment and widened QRS complex in severe cases. *ECG changes due to hyperkalemia* - **Hyperkalemia** classically manifests as tall, **peaked T waves**, followed by a prolonged PR interval, widened QRS complex, and eventual sine wave pattern as it worsens. - These changes are distinctly different from the prolonged QT interval seen in hypocalcemia.

Q: Graham Steell murmur is associated with which of the following conditions?

Pulmonary Regurgitation (PR). ***Pulmonary Regurgitation (PR)*** - The **Graham Steell murmur** is a high-pitched, decrescendo early diastolic murmur heard best at the left sternal border associated with **pulmonary hypertension**. [1] - It results from dilation of the pulmonary artery due to **elevated pulmonary pressures**, leading to functional pulmonary valve regurgitation. [1] *Tricuspid Regurgitation (TR)* - TR typically presents as a **holosystolic murmur** best heard at the left lower sternal border, often increasing with inspiration (Carvallo's sign). - It is caused by improper coaptation of the tricuspid valve leaflets, often due to **right ventricular dilation**. *Tricuspid Stenosis (TS)* - TS is characterized by a **diastolic rumble** heard best at the lower left sternal border, often with an opening snap. [2] - It is relatively rare and often associated with **rheumatic heart disease**. *Pulmonary Stenosis (PS)* - PS typically produces a **systolic ejection murmur** heard at the upper left sternal border, often radiating to the back. - It is caused by **obstruction to blood flow** from the right ventricle to the pulmonary artery.

Q: Treatment of choice for prinzmetal's angina

Calcium Channel Blockers (CCBs). ***Calcium Channel Blockers (CCBs)*** - **Dihydropyridine** CCBs like nifedipine or amlodipine, and **non-dihydropyridine** CCBs like diltiazem or verapamil, are the **first-line agents** for Prinzmetal's angina [1]. - They work by **relaxing coronary smooth muscle**, preventing the vasospasm that causes the angina [1]. *Nitroglycerin* - **Nitroglycerin is effective** for acute relief of Prinzmetal's angina symptoms due to its **vasodilatory properties**. - However, it's typically used as **rescue therapy** and not as a long-term preventative treatment. *Beta-blockers* - Beta-blockers are **contraindicated** in Prinzmetal's angina as they can **worsen coronary vasospasm** by blocking beta-2 mediated vasodilation, leaving unopposed alpha-1 vasoconstriction [2]. - They can increase the **frequency and severity of attacks**. *Prazosin* - Prazosin is an **alpha-1 adrenergic blocker** used primarily for **hypertension** and benign prostatic hyperplasia. - While it can cause vasodilation, it is **not the treatment of choice** for Prinzmetal's angina and is less effective than CCBs in preventing coronary spasm.

Q: In the management of a patient with acute myocardial infarction, which of the following is the most critical step in the initial treatment?

Administering aspirin. - **Aspirin** is crucial in the immediate management of **acute myocardial infarction (AMI)** due to its **antiplatelet effects**, which prevent further thrombus formation in the coronary arteries [1]. - It rapidly inhibits **cyclooxygenase-1 (COX-1)**, reducing **thromboxane A2** production and thus platelet aggregation, limiting infarct size and improving outcomes. *Performing coronary angiography* - While essential for definitive diagnosis and revascularization (e.g., PCI), **coronary angiography** is typically performed after initial medical stabilization and is not the *first* critical step [2]. - Delay in initial medical therapy to prioritize angiography can worsen myocardial damage. *Initiating thrombolytic therapy* - **Thrombolytic therapy** is a revascularization strategy, similar to PCI, used when immediate catheterization is not available, but it comes with a risk of bleeding [3]. - It is often initiated after **aspirin** and other immediate stabilizing medications, and its use depends on specific criteria and contraindications [3]. *Administering beta-blockers* - **Beta-blockers** are important in AMI management to reduce myocardial oxygen demand, control arrhythmias, and improve long-term outcomes. - However, their administration typically follows **aspirin** and other initial stabilizing measures, and they may be contraindicated in certain conditions like **acute heart failure** or **bradycardia** [2].

Q: Which condition is associated with a left axis deviation of -30° to -60°?

Left ventricular hypertrophy (LVH). ***Left ventricular hypertrophy (LVH)*** - **Left ventricular hypertrophy** often leads to an increased mass of the left ventricle, causing the electrical axis to shift leftward, potentially resulting in **left axis deviation** between -30° and -90° [1]. - The electrical activity generated by the hypertrophied left ventricle dominates, pulling the mean QRS vector towards the **left and inferior direction** [1]. *Right ventricular hypertrophy (RVH)* - **Right ventricular hypertrophy** typically causes a **right axis deviation**, pushing the electrical axis beyond +90° [1]. - The increased muscle mass of the right ventricle pulls the electrical vector towards the **right and inferior direction**. *Aortic stenosis (AS)* - While **aortic stenosis** can *cause* **left ventricular hypertrophy** due to increased afterload, it is not the direct ECG finding. LVH is the direct ECG manifestation. - The primary ECG change in AS is often **LVH**, which consequently leads to **left axis deviation**, but AS itself is a valvular disease. *Left atrial enlargement (LAE)* - **Left atrial enlargement** primarily affects the P wave, causing changes such as a **notched P wave (P mitrale)** or a prolonged P wave duration. - While LAE can occur with conditions that cause LVH, it does not directly lead to **left axis deviation** of the QRS complex.

Q: Tall T waves on ECG are seen in:

Hyperkalemia. ***Hyperkalemia*** - **Tall, peaked T waves** are a hallmark ECG finding in early to moderate **hyperkalemia**, reflecting altered repolarization due to elevated extracellular potassium [1]. - As potassium levels rise further, other ECG changes may include a **prolonged PR interval**, **widened QRS complex**, and ultimately a **sine wave pattern**, leading to ventricular arrhythmias [1]. *Hypokalemia* - This condition is typically associated with **flattened or inverted T waves**, prominent **U waves**, and a **prolonged QT interval** on the ECG [1]. - The ECG changes in hypokalemia reflect delayed repolarization and increased myocardial instability [1]. *Hypercalcemia* - **Hypercalcemia** is characterized by a **shortened QT interval** on the ECG due to accelerated ventricular repolarization. - T waves, if affected, are usually not tall or peaked but may be wider or slightly less prominent. *Hypocalcemia* - **Hypocalcemia** typically leads to a **prolonged QT interval** on the ECG, primarily due to a lengthened ST segment. - While it can manifest with various T wave morphologies, it does not typically cause the characteristic tall, peaked T waves seen in hyperkalemia.

Q: In Marfan's syndrome, Aortic aneurysm occurs most commonly in:

Ascending aorta. ***Ascending aorta*** - The **ascending aorta** is the most common site for aortic aneurysm and dissection in Marfan syndrome due to cystic medial degeneration weakening the vessel wall [1]. - This predisposition is linked to defects in the **fibrillin-1 gene (FBN1)**, severely impacting the structural integrity of the arterial media primarily in the ascending aorta [1]. *Descending aorta* - While possible, **descending aortic** involvement is less common than ascending aortic involvement in Marfan syndrome [2]. - Aneurysms here are more frequently associated with atherosclerosis or other connective tissue disorders. *Abdominal aorta* - **Abdominal aortic aneurysms** are relatively rare in Marfan syndrome and are more typically seen in older patients with atherosclerosis [3]. - The disease primarily affects the elastic tissue content, which is most abundant in the proximal aorta. *Arch of aorta* - Aortic arch aneurysms can occur, but they are still less frequent than those in the **ascending aorta** as the primary initial site of dilation and dissection in Marfan syndrome. - Arch involvement often represents an extension of a more proximal ascending aortic pathology.

Question 1

Torsades de pointes is seen in all except

Accepted Answer

Hyponatremia

Answer

Hypomagnesemia

Answer

Hypokalemia

Answer

Hypocalcemia

Question 2

Absent P Wave is seen on an ECG in:

Accepted Answer

Atrial Fibrillation (AF)

Answer

Cor Pulmonale

Answer

Mitral Stenosis

Answer

Chronic Obstructive Pulmonary Disease (COPD)

Question 3

Diagnose the underlying medical disorder based on the ECG changes.

Accepted Answer

ECG changes due to hypocalcemia

Answer

ECG changes due to hypokalemia

Answer

ECG changes due to hypercalcemia

Answer

ECG changes due to hyperkalemia

Question 4

What is the most likely cause of fluid overload in a patient presenting with shortness of breath?

Accepted Answer

Cardiac failure

Answer

Nephritic syndrome

Answer

TB

Answer

Portal hypertension

Question 5

Graham Steell murmur is associated with which of the following conditions?

Accepted Answer

Pulmonary Regurgitation (PR)

Answer

Tricuspid Regurgitation (TR)

Answer

Tricuspid Stenosis (TS)

Answer

Pulmonary Stenosis (PS)

Question 6

Treatment of choice for prinzmetal's angina

Accepted Answer

Calcium Channel Blockers (CCBs)

Answer

Nitroglycerin

Answer

Prazosin

Answer

Beta-blockers

Question 7

In the management of a patient with acute myocardial infarction, which of the following is the most critical step in the initial treatment?

Accepted Answer

Administering aspirin

Answer

Administering beta-blockers

Answer

Performing coronary angiography

Answer

Initiating thrombolytic therapy

Question 8

Which condition is associated with a left axis deviation of -30° to -60°?

Accepted Answer

Left ventricular hypertrophy (LVH)

Answer

Right ventricular hypertrophy (RVH)

Answer

Aortic stenosis (AS)

Answer

Left atrial enlargement (LAE)

Question 9

Tall T waves on ECG are seen in:

Accepted Answer

Hyperkalemia

Answer

Hypokalemia

Answer

Hypercalcemia

Answer

Hypocalcemia

Question 10

In Marfan's syndrome, Aortic aneurysm occurs most commonly in:

Accepted Answer

Ascending aorta

Answer

Descending aorta

Answer

Abdominal aorta

Answer

Arch of aorta

Cardiology — MCQs

Cardiology — MCQs

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