A man presents with chest pain, and his ECG shows ST segment depression in leads V1 to V4. Which of the following medications is contraindicated?
Q1682
Coarctation of the aorta is associated with which of the following?
Q1683
Features of Torsade de pointes include which of the following?
Q1684
What is the first-line treatment for rate control in a 60-year-old man with a history of atrial fibrillation who presents with palpitations and shortness of breath?
Cardiology Indian Medical PG Practice Questions and MCQs
Question 1681: A man presents with chest pain, and his ECG shows ST segment depression in leads V1 to V4. Which of the following medications is contraindicated?
A. Morphine
B. Aspirin
C. Beta blocker
D. Thrombolytic (Correct Answer)
Explanation: ***Thrombolytic***
- The ECG findings of **ST segment depression** in leads V1-V4 suggest **ischemia** or possibly a **non-ST elevation myocardial infarction (NSTEMI)** or **posterior MI**, but not an **ST elevation myocardial infarction (STEMI)**.
- **Thrombolytics** are contraindicated in NSTEMI and are primarily reserved for STEMI when PCI is not available or delayed, due to the risk of bleeding without significant benefit [1].
*Beta blocker*
- **Beta blockers** are often indicated in chest pain suspected to be cardiac in origin to reduce myocardial oxygen demand and improve outcomes, unless contraindicated by **bradycardia**, **hypotension**, or **heart failure** [1].
- They help decrease **heart rate** and **blood pressure**, lessening the workload on the heart [2].
*Morphine*
- **Morphine** is used for significant pain relief in acute coronary syndromes, including NSTEMI, as it can reduce pain and anxiety [3].
- It works by reducing **preload** and **afterload** through systemic venodilation, which in turn reduces myocardial oxygen demand [3].
*Aspirin*
- **Aspirin** is a cornerstone of therapy for acute coronary syndromes, including NSTEMI, due to its **antiplatelet effects** [4].
- It inhibits **platelet aggregation**, preventing further thrombus formation and reducing the risk of ischemic events [4].
Question 1682: Coarctation of the aorta is associated with which of the following?
A. TAPVC
B. Bicuspid aortic valve (Correct Answer)
C. PDA
D. Non-cyanotic heart defects
Explanation: ***Bicuspid aortic valve***
- **Coarctation of the aorta** is strongly associated with a **bicuspid aortic valve**, which is a congenital abnormality where the aortic valve has only two cusps instead of the usual three [1].
- This association is clinically significant as patients with coarctation often require long-term follow-up for potential complications related to the bicuspid valve, such as **aortic stenosis** or **regurgitation** [1].
*TAPVC*
- **Total anomalous pulmonary venous connection (TAPVC)** is a **cyanotic heart defect** where all four pulmonary veins drain abnormally into the systemic venous circulation.
- It is not directly associated with coarctation of the aorta.
*PDA*
- A **patent ductus arteriosus (PDA)** is a common congenital heart defect, but it is not specifically or uniquely associated with coarctation of the aorta to the same extent as a bicuspid aortic valve.
- While PDA can coexist with coarctation, it is not a direct or defining association.
*Non-cyanotic heart defects*
- While **coarctation of the aorta** is generally considered a non-cyanotic heart defect (unless severe or complicated by other defects), this option is too broad and does not identify the specific, most prominent associated anomaly.
- There are numerous non-cyanotic heart defects, and this option does not provide the most relevant or specific association.
Question 1683: Features of Torsade de pointes include which of the following?
A. Prolonged QTc interval (Correct Answer)
B. Wide QRS complex
C. Short QRS complex
D. Short QTc interval
Explanation: ***Prolonged QTc interval***
- **Torsade de pointes** (TdP) is a polymorphic ventricular tachycardia characterized by a twisting of the QRS complex around the isoelectric line [1].
- It is almost invariably associated with a **prolonged QTc interval**, which can be congenital or acquired due to drugs or electrolyte imbalances [1],[4].
*Wide QRS complex*
- While TdP does involve **wide QRS complexes**, this is a general characteristic of most ventricular tachycardias and not specific enough to define Torsade de pointes [2].
- The distinctive feature of TdP is the **polymorphic nature** of the wide QRS complexes and their characteristic "twisting" pattern, which is rooted in the underlying repolarization abnormality [1].
*Short QRS complex*
- A **short QRS complex** is characteristic of supraventricular arrhythmias and is not seen in ventricular tachycardias like Torsade de pointes [3].
- Ventricular activation originates in the ventricles, leading to a **wider QRS** due to slower, aberrant conduction [2].
*Short QTc interval*
- A **short QTc interval** is linked to conditions like short QT syndrome, which can also cause arrhythmias but is not responsible for Torsade de pointes.
- TdP exclusively occurs in the setting of **prolonged ventricular repolarization**, reflected by a long QTc [1],[4].
Question 1684: What is the first-line treatment for rate control in a 60-year-old man with a history of atrial fibrillation who presents with palpitations and shortness of breath?
A. Amiodarone
B. Digoxin
C. Beta-blockers (Correct Answer)
D. Calcium channel blockers
Explanation: ***Beta-blockers***
- **Beta-blockers** are generally considered **first-line agents** for **rate control in atrial fibrillation** due to their effectiveness in reducing ventricular rate and improving symptoms [2].
- They work by blocking beta-adrenergic receptors, which **slows conduction** through the AV node [1].
*Amiodarone*
- **Amiodarone** is primarily an **antiarrhythmic drug** used for rhythm control, not typically first-line for rate control.
- It's reserved for cases where other rate control agents are ineffective or contraindicated, or in patients with **heart failure** where other rate controllers may be detrimental.
*Digoxin*
- **Digoxin** is a **less common first-line agent** for rate control in atrial fibrillation as its effects are often **suboptimal during exercise** and it has a narrow therapeutic index.
- It is more effective for rate control at rest and may be considered in patients with **heart failure with reduced ejection fraction** or those who are sedentary.
*Calcium channel blockers*
- While **non-dihydropyridine calcium channel blockers** (e.g., verapamil, diltiazem) are effective for rate control in atrial fibrillation, **beta-blockers are often preferred as first-line** options unless contraindications exist.
- They also **slow AV nodal conduction** but may have disadvantages such as **negative inotropic effects** that can be problematic in certain patients.
