Cardiovascular Drugs — MCQs

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?

Q527Easy

Which of the following drugs is NOT useful in acute myocardial infarction?

Q528Medium

A 53-year-old woman presents with a history of hypertension. On follow-up, she is found to be hypertensive again and is prescribed hydralazine, a beta-blocker, and furosemide. She takes no other medications. She complains of muscle aches, joint pain, and a rash. Physical examination reveals a temperature of 37.7°C (100.0°F) and a scaling erythematous rash on her face. Laboratory investigations show positive antinuclear antibodies (ANA) and positive anti-histone antibodies. What is the most likely diagnosis?

Q529Medium

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

Q530Medium

All of the following are used in atrial arrhythmias except:

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 521: A 56-year-old man underwent a four-vessel coronary artery bypass graft procedure and was placed on prophylactic daily aspirin therapy. Aspirin has been shown to prevent recurrent myocardial infarction through its ability to inhibit the synthesis of what?

A. Adenosine diphosphate (ADP)
B. Leukotriene B4 (LTB4)
C. Nitric oxide (NO)
D. Thromboxane A2 (TXA2) (Correct Answer)

Explanation: **Explanation:** **1. Why Thromboxane A2 (TXA2) is correct:** Aspirin (Acetylsalicylic acid) is a cornerstone of secondary prophylaxis in cardiovascular disease. It works by **irreversibly inhibiting the enzyme Cyclooxygenase-1 (COX-1)** via acetylation of a serine residue. In platelets, COX-1 is responsible for converting arachidonic acid into Prostaglandin H2, which is then converted into **Thromboxane A2 (TXA2)**. TXA2 is a potent vasoconstrictor and a key mediator of platelet aggregation. By inhibiting TXA2 synthesis for the lifetime of the platelet (approx. 7–10 days), aspirin prevents the formation of arterial thrombi, thereby reducing the risk of recurrent myocardial infarction. **2. Why the other options are incorrect:** * **A. Adenosine diphosphate (ADP):** ADP is a platelet aggregator stored in alpha-granules. Its receptors (P2Y12) are the target of drugs like **Clopidogrel, Prasugrel, and Ticagrelor**, not aspirin. * **B. Leukotriene B4 (LTB4):** LTB4 is a product of the **Lipoxygenase (LOX) pathway**, which is involved in inflammation and chemotaxis. Aspirin does not inhibit the LOX pathway; in fact, inhibiting COX can sometimes shunt arachidonic acid toward the LOX pathway (the mechanism behind aspirin-induced asthma). * **C. Nitric oxide (NO):** NO is an endogenous vasodilator produced by endothelial cells. Aspirin does not inhibit its synthesis. **3. NEET-PG High-Yield Pearls:** * **Irreversible Action:** Aspirin is the only NSAID that binds irreversibly to COX enzymes. * **Low Dose vs. High Dose:** At low doses (75–150 mg), aspirin is selective for COX-1 (anti-platelet). At higher doses, it inhibits COX-2 (anti-inflammatory/analgesic). * **Endothelial Sparing:** While aspirin also inhibits Prostacyclin (PGI2—an anti-aggregator) in endothelial cells, these cells can synthesize new COX enzymes, whereas platelets cannot. This shifts the balance toward an anti-thrombotic state. * **Zero-order kinetics:** Aspirin follows zero-order elimination at toxic/therapeutic doses.

Question 522: Which of the following does not affect the secretion of renin?

A. Propranolol
B. Indomethacin
C. Enalkiren (Correct Answer)
D. None of the above

Explanation: Renin secretion is a tightly regulated process primarily controlled by the juxtaglomerular (JG) cells in the kidney. The correct answer is **Enalkiren** because it is a **Direct Renin Inhibitor (DRI)**; it inhibits the *activity* of renin rather than its *secretion*. ### Why Enalkiren is Correct Enalkiren (and the more commonly known Aliskiren) binds to the active site of the renin enzyme, preventing it from converting Angiotensinogen to Angiotensin I. Because it blocks the negative feedback loop of the Renin-Angiotensin-Aldosterone System (RAAS), it actually causes a **compensatory increase** in plasma renin concentration (PRC), though it decreases plasma renin activity (PRA). It does not suppress the secretion itself. ### Why the Other Options are Incorrect * **Propranolol:** Renin secretion is mediated by **$\beta_1$-receptors** on JG cells. $\beta$-blockers like Propranolol inhibit these receptors, thereby **decreasing** the secretion of renin. * **Indomethacin:** Prostaglandins (especially $PGE_2$ and $PGI_2$) stimulate renin release. NSAIDs like Indomethacin inhibit cyclooxygenase (COX), reducing prostaglandin synthesis and subsequently **decreasing** renin secretion. ### NEET-PG High-Yield Pearls * **Factors Increasing Renin Secretion:** Hypotension, decreased NaCl delivery to macula densa, sympathetic stimulation ($\beta_1$), and Prostaglandins. * **Factors Decreasing Renin Secretion:** Hypertension, increased NaCl delivery, Angiotensin II (negative feedback), and drugs like $\beta$-blockers and NSAIDs. * **Aliskiren/Enalkiren:** These are the only drugs that increase Plasma Renin Concentration (PRC) while simultaneously decreasing Plasma Renin Activity (PRA). This distinction is a common examiner favorite.

Question 523: Which of the following drugs is a direct renin inhibitor?

A. Candesartan
B. Aliskiren (Correct Answer)
C. Quinopril
D. Benazepril

Explanation: **Explanation:** The correct answer is **Aliskiren**. **1. Why Aliskiren is correct:** Aliskiren is currently the only clinically approved **Direct Renin Inhibitor (DRI)**. It works at the first and rate-limiting step of the Renin-Angiotensin-Aldosterone System (RAAS) by binding to the active site of renin. This prevents the conversion of Angiotensinogen to Angiotensin I. By inhibiting the system at its origin, it reduces levels of Angiotensin I, Angiotensin II, and aldosterone, and uniquely decreases **Plasma Renin Activity (PRA)**—unlike ACE inhibitors and ARBs, which cause a compensatory increase in PRA. **2. Why the other options are incorrect:** * **Candesartan (Option A):** This is an **Angiotensin II Receptor Blocker (ARB)**. It selectively blocks the $AT_1$ receptor, preventing the actions of Angiotensin II. * **Quinapril and Benazepril (Options C & D):** These are **ACE Inhibitors**. They prevent the conversion of Angiotensin I to Angiotensin II by inhibiting the Angiotensin-Converting Enzyme. They are prodrugs (except Captopril and Lisinopril). **3. High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Aliskiren blocks the conversion of Angiotensinogen $\rightarrow$ Angiotensin I. * **Pharmacokinetics:** It has very low oral bioavailability (~3%) which is further reduced by high-fat meals. * **Contraindications:** It is strictly **contraindicated in pregnancy** (teratogenic) and should not be combined with ACE inhibitors or ARBs in patients with diabetes or renal impairment due to the risk of hyperkalemia and hypotension (ALTITUDE trial). * **Side Effects:** Hyperkalemia, diarrhea (at high doses), and angioedema (rare).

Question 524: A 45-year-old man with dilated cardiomyopathy and atrial fibrillation presents with a rapid ventricular rate. An agent is used to control the ventricular rate, but it also affects cardiac contractility. Which agent was most likely used?

A. Verapamil (Correct Answer)
B. Digoxin
C. Nifedipine
D. Amiodarone

Explanation: **Explanation:** The clinical objective in this patient is **rate control** for atrial fibrillation. The question specifies that the agent used not only controls the ventricular rate but also significantly affects **cardiac contractility**. **1. Why Verapamil is correct:** Verapamil is a non-dihydropyridine Calcium Channel Blocker (CCB) that acts on the L-type calcium channels in the AV node and the myocardium. It is a potent **negative inotrope** (decreases contractility) and **negative chronotrope/dromotrope**. In a patient with dilated cardiomyopathy, Verapamil can acutely worsen heart failure due to this profound depressant effect on myocardial contractility, making it a high-yield contraindication in such cases. **2. Why the other options are incorrect:** * **Digoxin:** While it is used for rate control in AF (by increasing vagal tone at the AV node), it is a **positive inotrope**. It increases contractility, which contradicts the question's premise of an agent that negatively affects it. * **Nifedipine:** This is a dihydropyridine CCB. It acts primarily on vascular smooth muscle (vasodilation) and has **minimal to no effect** on the AV node or cardiac contractility at clinical doses. It is not used for rate control. * **Amiodarone:** While it can be used for rhythm/rate control, its effect on contractility is much less significant compared to Verapamil. It is often the preferred agent in patients with heart failure because it is relatively "heart-failure friendly." **Clinical Pearls for NEET-PG:** * **Verapamil & Diltiazem** are contraindicated in Heart Failure with Reduced Ejection Fraction (HFrEF) due to negative inotropy. * **Drug of choice** for rate control in AF with Heart Failure: **Digoxin or Beta-blockers** (cautiously). * **Drug of choice** for rate control in AF with WPW syndrome: **Procainamide** (Avoid ABCD: Atenolol, Beta-blockers, CCBs, Digoxin).

Question 525: What is the first-line antihypertensive drug of choice in a diabetic patient?

A. Methyldopa
B. Beta blocker
C. ACE inhibitor (Correct Answer)
D. Thiazides

Explanation: **Explanation:** **1. Why ACE Inhibitors (ACEIs) are the Correct Choice:** ACE inhibitors (e.g., Enalapril, Lisinopril) are the first-line antihypertensive agents in diabetic patients primarily due to their **renoprotective effects**. In diabetes, high glucose levels lead to increased Angiotensin II, which causes vasoconstriction of the **efferent arteriole** of the kidney. This increases intraglomerular pressure, leading to albuminuria and diabetic nephropathy. ACEIs (and ARBs) dilate the efferent arteriole, reducing intraglomerular pressure and slowing the progression of chronic kidney disease (CKD). **2. Why Other Options are Incorrect:** * **Methyldopa:** This is a centrally acting alpha-2 agonist. Its primary clinical use is as a first-line agent for hypertension in **pregnancy**, not diabetes. * **Beta Blockers:** These are generally avoided as first-line therapy in diabetics because they can **mask the warning signs of hypoglycemia** (like tachycardia and tremors) and may worsen insulin resistance. * **Thiazides:** While effective antihypertensives, they can cause **hyperglycemia** (by inhibiting insulin release) and hyperlipidemia, which are undesirable in a diabetic profile. **3. NEET-PG High-Yield Pearls:** * **Drug of Choice (DOC):** If a patient has both Diabetes and Hypertension, the DOC is an **ACEI**. If the patient develops a dry cough (due to bradykinin accumulation), switch to an **ARB** (e.g., Losartan). * **Renoprotection:** ACEIs are indicated in diabetic patients even if they are normotensive if **microalbuminuria** (30–300 mg/day) is present. * **Contraindication:** ACEIs are strictly contraindicated in **pregnancy** (teratogenic) and **bilateral renal artery stenosis**.

Question 526: 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?

A. Nifedipine
B. Hydrochlorothiazide
C. Atenolol (Correct Answer)
D. Methyldopa

Explanation: **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).

Question 527: Which of the following drugs is NOT useful in acute myocardial infarction?

A. Nifedipine (Correct Answer)
B. Aspirin
C. ACE inhibitors
D. Metoprolol

Explanation: In the management of Acute Myocardial Infarction (AMI), the primary goal is to restore perfusion and reduce myocardial oxygen demand. **Why Nifedipine is NOT useful (and potentially harmful):** Nifedipine is a short-acting dihydropyridine calcium channel blocker. It causes potent peripheral vasodilation, which triggers **reflex tachycardia** and increased sympathetic activity. This increases myocardial oxygen demand and can worsen ischemia or even extend the infarct. Large clinical trials (like the SPRINT study) demonstrated that short-acting nifedipine increases mortality in AMI patients. Therefore, it is contraindicated in the acute phase of MI. **Why the other options are used:** * **Aspirin:** An antiplatelet agent that inhibits thromboxane A2 synthesis. It is the first-line drug given immediately to prevent further thrombus propagation and has been shown to significantly reduce mortality. * **ACE Inhibitors (e.g., Enalapril, Ramipril):** These are started within 24 hours of an MI. They prevent **ventricular remodeling**, reduce afterload, and decrease the risk of heart failure and subsequent mortality. * **Metoprolol:** A cardioselective beta-blocker. It reduces heart rate, contractility, and blood pressure, thereby decreasing myocardial oxygen demand. It also reduces the risk of post-MI arrhythmias (ventricular fibrillation). **High-Yield Clinical Pearls for NEET-PG:** * **Diltiazem/Verapamil:** These non-dihydropyridines may be used in AMI *only* if beta-blockers are contraindicated and there is no heart failure. * **Mnemonic for AMI Management:** **MONA** (Morphine, Oxygen, Nitroglycerin, Aspirin). * **ACE Inhibitors** are most beneficial in patients with anterior wall MI or those with an ejection fraction <40%.

Question 528: A 53-year-old woman presents with a history of hypertension. On follow-up, she is found to be hypertensive again and is prescribed hydralazine, a beta-blocker, and furosemide. She takes no other medications. She complains of muscle aches, joint pain, and a rash. Physical examination reveals a temperature of 37.7°C (100.0°F) and a scaling erythematous rash on her face. Laboratory investigations show positive antinuclear antibodies (ANA) and positive anti-histone antibodies. What is the most likely diagnosis?

A. Systemic lupus erythematosus
B. Hydralazine-induced lupus erythematosus (Correct Answer)
C. Beta-blocker-induced systemic lupus erythematosus
D. Furosemide-induced systemic lupus erythematosus

Explanation: ### Explanation **Correct Answer: B. Hydralazine-induced lupus erythematosus** The patient presents with the classic triad of **Drug-Induced Lupus Erythematosus (DILE)**: fever, arthralgia (joint pain), and a rash, following the initiation of **Hydralazine**. The definitive diagnostic clues in this clinical vignette are: 1. **Pharmacological Trigger:** Hydralazine is a well-known cause of DILE. It is often prescribed with a beta-blocker (to prevent reflex tachycardia) and a diuretic (to prevent fluid retention), as seen in this patient. 2. **Serology:** The presence of **Anti-histone antibodies** is highly specific ( >95%) for DILE. While Antinuclear Antibodies (ANA) are positive, **Anti-dsDNA antibodies** (typical of idiopathic SLE) are usually absent. 3. **Metabolism:** Hydralazine is metabolized via **Phase II acetylation**. "Slow acetylators" are at a significantly higher risk of developing this condition. **Why incorrect options are wrong:** * **Option A:** While the symptoms overlap with Systemic Lupus Erythematosus (SLE), the strong association with a specific drug, the presence of anti-histone antibodies, and the absence of renal/CNS involvement point specifically to DILE. * **Options C & D:** Neither beta-blockers nor furosemide are recognized triggers for drug-induced lupus. **High-Yield NEET-PG Pearls:** * **Common Drugs causing DILE (Mnemonic: SHIP):** **S**ulfonamides, **H**ydralazine, **I**soniazid, **P**rocainamide (highest risk). Others include Phenytoin and Minocycline. * **Key Serology:** Anti-histone antibodies (+) is the hallmark; Anti-dsDNA (-) and normal complement levels help differentiate it from idiopathic SLE. * **Clinical Presentation:** Unlike idiopathic SLE, DILE rarely involves the kidneys or the Central Nervous System. * **Management:** Symptoms typically resolve spontaneously upon **discontinuation** of the offending drug.

Question 529: Angiotensin converting enzyme inhibitors are not used in congestive heart failure resulting from which of the following conditions?

A. Mitral stenosis
B. Aortic regurgitation
C. Alcoholic cardiomyopathy
D. Aortic stenosis (Correct Answer)

Explanation: **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 530: All of the following are used in atrial arrhythmias except:

A. Digoxin
B. Verapamil
C. Quinidine
D. Lignocaine (Correct Answer)

Explanation: **Explanation:** The correct answer is **Lignocaine (Lidocaine)**. The fundamental principle in treating arrhythmias is understanding the site of action of the drug. Lignocaine is a **Class IB antiarrhythmic** that acts by blocking activated and inactivated sodium channels. Its unique pharmacological property is its high affinity for channels in the **ventricular myocardium**, especially in ischemic or depolarized tissues. It has negligible effects on the atrial myocardium and the AV node, making it **ineffective for atrial arrhythmias** (like atrial fibrillation or flutter). It is primarily used for ventricular tachycardia and arrhythmias following myocardial infarction. **Why the other options are used in atrial arrhythmias:** * **Digoxin:** A cardiac glycoside that increases vagal tone, slowing conduction through the AV node. It is used for **rate control** in atrial fibrillation and flutter. * **Verapamil:** A Class IV antiarrhythmic (Calcium Channel Blocker) that slows AV nodal conduction and prolongs the refractory period. It is a first-line agent for terminating **Paroxysmal Supraventricular Tachycardia (PSVT)** and controlling rate in atrial fibrillation. * **Quinidine:** A Class IA antiarrhythmic that blocks sodium channels and has some potassium channel blocking activity. It can be used for the **rhythm control** (conversion and maintenance) of atrial fibrillation. **High-Yield Clinical Pearls for NEET-PG:** * **Lignocaine** is the drug of choice for **ventricular arrhythmias** occurring during cardiac surgery or post-MI, but it is ineffective when given orally due to high first-pass metabolism. * **Adenosine** is the drug of choice for the acute termination of PSVT. * **Amiodarone** is a "broad-spectrum" antiarrhythmic effective for both atrial and ventricular arrhythmias.

Practice by Chapter

Antihypertensive Agents

Practice Questions

Drugs for Heart Failure

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Antiarrhythmic Drugs

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Antianginal Agents

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Lipid-Lowering Drugs

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Anticoagulants and Antiplatelet Drugs

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Thrombolytic Agents

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Drugs Used in Pulmonary Hypertension

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Drugs Used in Shock

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Cardiovascular Effects of Non-Cardiovascular Drugs

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