Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 151: Digitalis does not affect which parameter of the heart?

A. Heart rate
B. Contractility
C. Coronary blood flow
D. None of the above (Correct Answer)

Explanation: **Explanation:** Digitalis (Digoxin) is a cardiac glycoside that exerts significant effects on multiple parameters of cardiac physiology. The correct answer is **"None of the above"** because Digitalis affects heart rate, contractility, and coronary blood flow. 1. **Contractility (Positive Inotropy):** Digitalis inhibits the **Na⁺/K⁺-ATPase pump**, leading to an increase in intracellular Na⁺. This reduces the activity of the Na⁺/Ca²⁺ exchanger, resulting in higher intracellular Ca²⁺ levels, which directly increases the force of myocardial contraction. 2. **Heart Rate (Negative Chronotropy):** Digitalis increases **vagal (parasympathetic) tone** and decreases sympathetic activity. This slows the firing of the SA node and prolongs conduction through the AV node, effectively reducing the heart rate. 3. **Coronary Blood Flow:** In a healthy heart, Digitalis can cause mild vasoconstriction. However, in a failing heart, the increase in cardiac output and the reduction in ventricular wall tension (due to better emptying) lead to an indirect **improvement in coronary perfusion**. **Why other options are incorrect:** Options A, B, and C are all parameters significantly altered by Digitalis therapy. Since the drug influences all three, "None of the above" is the only logical choice. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Inhibition of Na⁺/K⁺-ATPase (the "Digitalis Receptor"). * **ECG Changes:** Characterized by the **"Reverse Tick" sign** or "Sagging" ST-segment depression. * **Toxicity:** Hypokalemia predisposes to Digoxin toxicity. The most common arrhythmia is **Ventricular Bigeminy**, while the most characteristic is **Atrial Tachycardia with AV block**. * **Therapeutic Range:** Narrow (0.5–2 ng/mL).

Question 152: Which of the following drugs does not decrease angiotensin II activity?

A. Enalapril
B. Valsartan
C. Nesiritide (Correct Answer)
D. Omapatrilat

Explanation: ### Explanation The question asks for the drug that does **not** decrease Angiotensin II (AT-II) activity. To answer this, one must distinguish between drugs that inhibit the Renin-Angiotensin-Aldosterone System (RAAS) and those that act on the Natriuretic Peptide system. **Why Nesiritide is the correct answer:** **Nesiritide** is a recombinant form of **B-type Natriuretic Peptide (BNP)**. Its primary mechanism is to increase intracellular cGMP, leading to potent vasodilation and natriuresis. While it counteracts the *effects* of the RAAS system physiologically, it does not directly decrease the production or receptor-binding activity of Angiotensin II. In fact, by causing vasodilation and potentially lowering blood pressure, it does not inherently inhibit the RAAS cascade. **Analysis of Incorrect Options:** * **Enalapril:** An **ACE Inhibitor**. It directly prevents the conversion of Angiotensin I to Angiotensin II, thereby decreasing AT-II levels. * **Valsartan:** An **Angiotensin Receptor Blocker (ARB)**. It binds to and blocks the $AT_1$ receptor, directly decreasing the activity/binding of AT-II. * **Omapatrilat:** A **Vasopeptidase Inhibitor**. It inhibits both ACE and Neprilysin. By inhibiting ACE, it directly decreases the production of Angiotensin II. **Clinical Pearls for NEET-PG:** * **Omapatrilat** was never FDA-approved due to a high risk of **angioedema**, caused by a "double hit" of bradykinin accumulation (both ACE and Neprilysin break down bradykinin). * **Sacubitril/Valsartan (ARNI)** is the modern clinical successor to Omapatrilat; it combines a Neprilysin inhibitor with an ARB to avoid the angioedema risk associated with combining it with an ACEI. * **Nesiritide** is used in acutely decompensated heart failure but must be monitored for causing significant hypotension.

Question 153: Which of the following drugs is NOT used in the management of acute myocardial infarction?

A. Plasminogen activator inhibitors (Correct Answer)
B. Thrombolytics
C. Antiplatelet drugs
D. Alteplase

Explanation: **Explanation:** The management of **Acute Myocardial Infarction (AMI)** focuses on restoring coronary blood flow (reperfusion) and preventing further clot propagation. **Why Option A is Correct:** **Plasminogen activator inhibitors** (e.g., Tranexamic acid, Aminocaproic acid) are **antifibrinolytics**. They inhibit the conversion of plasminogen to plasmin, thereby preventing the breakdown of fibrin clots [4], [5]. In the context of AMI, where the goal is to dissolve an existing thrombus obstructing the coronary artery, these drugs are **contraindicated** as they would stabilize the clot and worsen the ischemia. **Why the other options are Incorrect:** * **B. Thrombolytics:** These are the mainstay of pharmacological reperfusion therapy. They dissolve the fibrin mesh of the thrombus to restore blood flow [5]. * **C. Antiplatelet drugs:** Aspirin and P2Y12 inhibitors (Clopidogrel, Ticagrelor) are essential in AMI to prevent further platelet aggregation and re-occlusion of the vessel [2]. * **D. Alteplase:** This is a specific recombinant tissue-type plasminogen activator (rt-PA) [1]. It is a fibrin-specific thrombolytic agent used to achieve rapid thrombolysis in ST-elevation MI (STEMI) [3]. **NEET-PG High-Yield Pearls:** * **MONA regimen:** The classic initial management for AMI includes **M**orphine, **O**xygen, **N**itroglycerin, and **A**spirin. * **Thrombolytics vs. Antifibrinolytics:** Remember that Thrombolytics (Alteplase, Reteplase, Tenecteplase) are "clot busters," while Antifibrinolytics (Tranexamic acid) are "clot stabilizers" used in bleeding disorders [5]. * **Time is Muscle:** Thrombolytics are most effective if administered within the first 6–12 hours of symptom onset if Primary PCI is unavailable [3], [5]. * **Tenecteplase** is currently preferred over Alteplase due to its higher fibrin specificity and ease of administration (single bolus) [1].

Question 154: Pulsus Bigeminus is seen in therapy with which of the following drug classes?

A. Beta blockers
B. ACE inhibitors
C. Digitalis (Correct Answer)
D. Calcium channel blockers

Explanation: ### Explanation **Pulsus Bigeminus** is a classic clinical sign of **Digitalis (Digoxin) toxicity**. It is characterized by a rhythm where a normal sinus beat is followed closely by a premature ventricular contraction (PVC), resulting in pairs of beats followed by a pause. #### Why Digitalis is Correct: Digitalis works by inhibiting the **Na+/K+ ATPase pump**, leading to an increase in intracellular calcium. While this enhances contractility (positive inotropy), an overload of intracellular calcium can cause **delayed after-depolarizations (DADs)**. These DADs trigger ectopic ventricular beats (PVCs). When every normal beat is followed by a PVC, it manifests as Pulsus Bigeminus. This is often considered one of the most characteristic arrhythmias of digoxin toxicity. #### Why Other Options are Incorrect: * **Beta-blockers:** These drugs decrease heart rate (negative chronotropy) and conduction velocity. Toxicity typically presents with **bradycardia** and various degrees of **heart block**, not bigeminy. * **ACE Inhibitors:** These act on the renin-angiotensin system to lower blood pressure. Their primary cardiac side effect is related to electrolyte imbalances (hyperkalemia), but they do not directly cause bigeminal rhythms. * **Calcium Channel Blockers (CCBs):** Verapamil and Diltiazem slow the AV node. Toxicity leads to severe bradycardia, hypotension, and heart block. #### High-Yield Clinical Pearls for NEET-PG: * **Most common arrhythmia** in Digoxin toxicity: Ventricular Premature Contractions (VPCs). * **Most characteristic/specific arrhythmia**: Atrial Tachycardia with AV block. * **ECG Changes (Digoxin Effect):** "Sagging" ST-segment depression (Hockey stick appearance) and shortened QT interval. * **Factors predisposing to toxicity:** Hypokalemia (most common), hypomagnesemia, and hypercalcemia. * **Antidote:** Digoxin-specific antibody fragments (Digibind).

Question 155: What is the advantage of using digoxin in Congestive Heart Failure (CHF)?

A. Provides relief of symptoms (Correct Answer)
B. Reverses the pathological changes of CHF
C. Prolongs the survival of CHF patients
D. All of the above

Explanation: **Explanation:** Digoxin is a cardiac glycoside that acts by inhibiting the **Na⁺/K⁺-ATPase pump**, leading to an increase in intracellular calcium and a subsequent **positive inotropic effect**. **1. Why Option A is correct:** The primary benefit of Digoxin in Congestive Heart Failure (CHF) is **symptomatic relief**. By increasing the force of myocardial contraction and decreasing the heart rate (via vagomimetic action), it improves cardiac output and decreases pulmonary congestion. This leads to a reduction in the frequency of hospitalizations and improved exercise tolerance. **2. Why Options B and C are incorrect:** * **Option B:** Digoxin does **not** reverse the underlying structural remodeling or pathological changes (like fibrosis or hypertrophy) associated with heart failure. Drugs that target the Renin-Angiotensin-Aldosterone System (RAAS), such as ACE inhibitors and Spironolactone, are required for this. * **Option C:** Large-scale clinical trials (notably the **DIG Trial**) have conclusively shown that Digoxin **does not reduce mortality** or prolong survival in CHF patients. It is "mortality-neutral." **High-Yield Clinical Pearls for NEET-PG:** * **Indications:** Digoxin is specifically indicated in CHF patients who remain symptomatic despite optimal therapy or those with co-existing **Atrial Fibrillation** (due to its negative dromotropic effect on the AV node). * **Mortality-Reducing Drugs in CHF:** Remember the "Big Four": ACE inhibitors/ARBs, Beta-blockers, Aldosterone antagonists (Spironolactone), and SGLT2 inhibitors. * **Toxicity:** Hypokalemia predisposes to Digoxin toxicity because K⁺ and Digoxin compete for the same binding site on the Na⁺/K⁺-ATPase pump.

Question 156: Which of the following congenital malformations is seen in a child of a mother who is on treatment with oral anticoagulants?

A. Craniofacial malformations
B. Renal agenesis
C. Long bone defects (Correct Answer)
D. Chondrodysplasia punctata

Explanation: **Explanation:** The question refers to **Fetal Warfarin Syndrome (Warfarin Embryopathy)**. Warfarin is a low-molecular-weight oral anticoagulant that crosses the placenta. It interferes with the γ-carboxylation of glutamate residues in osteocalcin and other bone proteins, which are Vitamin K-dependent. This disruption leads to defective bone mineralization. **1. Why "Long bone defects" is the correct answer:** Exposure to warfarin during the first trimester (specifically weeks 6–9) results in significant skeletal abnormalities. The most characteristic features include **stippled epiphyses** (calcific stippling) and **limb hypoplasia**, which manifest as shortened or defective long bones. While "Chondrodysplasia punctata" is a clinical description of the stippling, the NEET-PG curriculum often categorizes the resulting structural outcome as **long bone defects** or limb hypoplasia. **2. Analysis of Incorrect Options:** * **Chondrodysplasia punctata (Option D):** While this is a feature of the syndrome, it is technically a *radiological finding* (stippled epiphyses) rather than the primary malformation itself. In many standardized exams, "long bone defects" is preferred as the broader anatomical malformation. * **Craniofacial malformations (Option A):** While nasal hypoplasia is common in this syndrome, "craniofacial malformations" is a broad term more classically associated with Retinoids or Phenytoin (Fetal Hydantoin Syndrome) [3]. * **Renal agenesis (Option B):** This is typically associated with **ACE inhibitors** (which cause renal dysgenesis and oligohydramnios) or NSAIDs, not oral anticoagulants [1], [2]. **Clinical Pearls for NEET-PG:** * **Safe Alternative:** Heparin (and LMWH) does not cross the placenta and is the anticoagulant of choice during pregnancy. * **Critical Period:** Teratogenicity is highest between **6–9 weeks** of gestation. * **CNS Effects:** Exposure in the 2nd/3rd trimester can cause CNS defects (microcephaly, optic atrophy) due to fetal hemorrhage. * **Key Triad:** Nasal hypoplasia, stippled epiphyses, and hypoplastic long bones.

Question 157: Which of the following is NOT a pleiotropic effect of statins?

A. Reduction of LDL cholesterol (Correct Answer)
B. Improved endothelial stability
C. Anti-inflammatory and anti-oxidant effects
D. Reduced plaque rupture

Explanation: **Explanation:** The term **"pleiotropic effects"** refers to the actions of a drug that are independent of its primary mechanism of action. Statins (HMG-CoA reductase inhibitors) primarily lower cholesterol by inhibiting the rate-limiting step in cholesterol synthesis. **1. Why Option A is correct:** The **reduction of LDL cholesterol** is the **primary therapeutic effect** of statins, not a pleiotropic one. Statins inhibit HMG-CoA reductase, leading to decreased intracellular cholesterol. This triggers an up-regulation of LDL receptors on hepatocytes, which clears LDL from the plasma. Since this is the intended pharmacological goal, it is categorized as the primary effect. **2. Why the other options are incorrect (Pleiotropic Effects):** Statins exert several beneficial cardiovascular effects that occur independently of LDL lowering, often mediated by the inhibition of isoprenoids (like geranylgeranyl pyrophosphate): * **Option B (Improved endothelial stability):** Statins increase the expression of endothelial nitric oxide synthase (eNOS), improving vasodilation and vascular health. * **Option C (Anti-inflammatory/Anti-oxidant):** Statins decrease C-reactive protein (CRP) levels and reduce the production of reactive oxygen species (ROS). * **Option D (Reduced plaque rupture):** Statins inhibit metalloproteinases and strengthen the fibrous cap of atherosclerotic plaques, making them "stable" and less likely to trigger an acute coronary syndrome. **Clinical Pearls for NEET-PG:** * **Most potent statin:** Rosuvastatin (followed by Atorvastatin). * **Best time to dose:** Simvastatin and Lovastatin should be taken at night (cholesterol synthesis peaks at night). Atorvastatin and Rosuvastatin have long half-lives and can be taken anytime. * **Key Side Effects:** Myopathy (monitored via CPK levels) and hepatotoxicity (monitored via ALT/AST). * **Contraindication:** Statins are strictly contraindicated in pregnancy (Teratogenic).

Question 158: A patient presents to the emergency department with severe bradycardia following a drug overdose. The drug was being taken for hypertension. Which of the following cannot be the drug?

A. Clonidine
B. Hydralazine (Correct Answer)
C. Propranolol
D. Reserpine

Explanation: **Explanation:** The core concept tested here is the distinction between drugs that decrease sympathetic outflow (or block it) and those that trigger a compensatory sympathetic response. **Why Hydralazine is the correct answer:** Hydralazine is a **direct-acting peripheral vasodilator** that primarily relaxes arteriolar smooth muscle. This sudden drop in peripheral vascular resistance triggers a potent **baroreceptor-mediated reflex tachycardia**. Because it causes an increase in heart rate rather than a decrease, an overdose of Hydralazine would present with tachycardia and hypotension, making it physiologically impossible for it to be the cause of severe bradycardia. **Analysis of Incorrect Options:** * **Clonidine:** An $\alpha_2$-adrenergic agonist that acts centrally to decrease sympathetic outflow. Overdose characteristically presents with the "Clonidine triad": hypotension, **bradycardia**, and miosis (mimicking opioid overdose). * **Propranolol:** A non-selective $\beta$-blocker. It directly decreases heart rate and AV conduction by blocking $\beta_1$ receptors in the heart, leading to profound **bradycardia** in overdose. * **Reserpine:** An adrenergic neuron blocker that depletes stores of norepinephrine, dopamine, and serotonin. By depleting cardiac norepinephrine, it leads to a dominant parasympathetic tone and **bradycardia**. **High-Yield Clinical Pearls for NEET-PG:** * **Reflex Tachycardia:** Common with "Pure" vasodilators like Hydralazine, Minoxidil, and Dihydropyridine Calcium Channel Blockers (e.g., Nifedipine). * **Drug-Induced Bradycardia:** Remember the mnemonic **"PACED"**: **P**ropranolol (Beta-blockers), **A**nticholinesterases, **C**lonidine/Calcium Channel Blockers (Verapamil/Diltiazem), **E**thanol, **D**igoxin. * **Hydralazine Side Effect:** It is classically associated with **Drug-Induced Lupus Erythematosus (DILE)** in slow acetylators.

Question 159: Inodilator is defined as:

A. Milrinone (Correct Answer)
B. Dopamine
C. Dobutamine
D. Thiazides

Explanation: ### Explanation **Concept of Inodilators** An **Inodilator** is a pharmacological agent that possesses both **positive inotropic** (increases myocardial contractility) and **vasodilatory** (reduces systemic and pulmonary vascular resistance) properties. **1. Why Milrinone is Correct:** Milrinone is a selective **Phosphodiesterase-3 (PDE3) inhibitor**. * **In Heart:** It prevents the breakdown of cAMP in cardiac myocytes, leading to increased calcium influx and increased contractility (Inotropy). * **In Blood Vessels:** Increased cAMP in vascular smooth muscle leads to relaxation and vasodilation. This dual action reduces preload and afterload while increasing cardiac output, making it ideal for acute heart failure and cardiogenic shock. **2. Analysis of Incorrect Options:** * **Dopamine:** A catecholamine with dose-dependent effects. At high doses, it acts on $\alpha_1$ receptors causing **vasoconstriction**, which is the opposite of an inodilator. * **Dobutamine:** Primarily a $\beta_1$ agonist. While it has some $\beta_2$ (vasodilatory) activity, it is traditionally classified as an **Inotrope**. Milrinone is the "classic" textbook example of an inodilator because its vasodilatory effect is more pronounced and independent of adrenergic receptors. * **Thiazides:** These are **Diuretics** used for hypertension and edema; they have no direct positive inotropic effect on the heart. **3. High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Milrinone increases cAMP by inhibiting PDE3. * **Clinical Use:** Short-term management of severe heart failure. * **Side Effect:** Can cause **arrhythmias** and **thrombocytopenia** (though less common than with its predecessor, Amrinone). * **Key Distinction:** Unlike Dobutamine, Milrinone’s action is **not** affected by $\beta$-blockers, making it useful in patients already on chronic $\beta$-blocker therapy.

Question 160: ACE inhibitor induced cough is mediated by?

A. Bradykinin
B. Substance-P
C. Prostaglandin
D. Renin (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Renin** *Note: In standard medical literature, ACE inhibitor-induced cough is primarily attributed to Bradykinin and Substance P. However, if "Renin" is marked as the correct answer in a specific exam context, it refers to the **upstream activation of the Renin-Angiotensin System (RAS)**. When ACE inhibitors block the conversion of Angiotensin I to Angiotensin II, the loss of negative feedback leads to a compensatory **increase in plasma Renin levels**. While Renin itself does not directly cause the cough, it is the biochemical marker of the system's blockade.* #### Why the other options are traditionally considered: * **A. Bradykinin:** ACE (Angiotensin Converting Enzyme) is identical to **Kininase II**, the enzyme responsible for breaking down bradykinin. Inhibition of ACE leads to the accumulation of bradykinin in the lungs, which sensitizes sensory nerve endings, leading to a dry, irritating cough. This is the most widely accepted mechanism. * **B. Substance-P:** Like bradykinin, Substance-P is a neuropeptide degraded by ACE. Its accumulation in the respiratory tract contributes to airway inflammation and the cough reflex. * **C. Prostaglandins:** Increased levels of bradykinin stimulate the synthesis of arachidonic acid metabolites, specifically **Prostaglandin E2 (PGE2)**, which further irritates the bronchial mucosa. #### NEET-PG High-Yield Clinical Pearls: * **Incidence:** ACE inhibitor-induced cough occurs in 5–20% of patients and is more common in **females** and the **Chinese population**. * **Management:** The cough is not dose-dependent. If it occurs, the drug must be stopped. The best alternative is an **ARB (Angiotensin Receptor Blocker)**, as ARBs do not affect Kininase II and do not increase bradykinin levels. * **Timeframe:** It typically appears within 1 week to 6 months of starting therapy and resolves within 1–4 weeks after discontinuation.

Practice by Chapter

Antihypertensive Agents

Practice Questions

Drugs for Heart Failure

Practice Questions

Antiarrhythmic Drugs

Practice Questions

Antianginal Agents

Practice Questions

Lipid-Lowering Drugs

Practice Questions

Anticoagulants and Antiplatelet Drugs

Practice Questions

Thrombolytic Agents

Practice Questions

Drugs Used in Pulmonary Hypertension

Practice Questions

Drugs Used in Shock

Practice Questions

Cardiovascular Effects of Non-Cardiovascular Drugs

Practice Questions

Want unlimited practice?

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

Start For Free