ECG Cardiac Pharmacology 1 — Questions and Answers
Question 1: Which class of medications slows the heart rate by blocking beta-adrenergic receptors?
- Beta-blockers (Correct answer)
- Calcium channel blockers
- ACE inhibitors
- Diuretics
Correct answer: Beta-blockers
Beta-blockers (e.g., metoprolol, atenolol) block beta-1 receptors in the heart, reducing heart rate, contractility, and blood pressure.
Question 2: What is the primary use of nitroglycerin in cardiac patients?
- To relieve angina by dilating blood vessels (Correct answer)
- To increase heart rate
- To prevent blood clots
- To lower cholesterol
Correct answer: To relieve angina by dilating blood vessels
Nitroglycerin is a vasodilator that relaxes smooth muscle in blood vessel walls, reducing cardiac workload and relieving angina (chest pain from reduced blood flow).
Question 3: Which anticoagulant is commonly used to prevent stroke in atrial fibrillation?
- Warfarin or DOACs (direct oral anticoagulants) (Correct answer)
- Aspirin alone
- Acetaminophen
- Statins
Correct answer: Warfarin or DOACs (direct oral anticoagulants)
Warfarin and DOACs (like apixaban, rivaroxaban) are used in atrial fibrillation to prevent blood clots from forming in the fibrillating atria, reducing stroke risk.
Question 4: What does atropine do to the heart rate?
- Increases it by blocking vagal (parasympathetic) tone (Correct answer)
- Decreases it
- Has no effect on heart rate
- Stops the heart temporarily
Correct answer: Increases it by blocking vagal (parasympathetic) tone
Atropine blocks the parasympathetic (vagal) input to the heart via muscarinic receptors, which removes the vagal brake and increases heart rate. It is used for symptomatic bradycardia.
Question 5: What is the antidote for warfarin overdose?
- Vitamin K (Correct answer)
- Protamine sulfate
- Naloxone
- Flumazenil
Correct answer: Vitamin K
Vitamin K reverses the anticoagulant effects of warfarin by restoring the production of vitamin K-dependent clotting factors (II, VII, IX, X).
Question 6: Why are statins prescribed for cardiac patients?
- To lower LDL cholesterol and reduce atherosclerosis risk (Correct answer)
- To increase heart rate
- To reduce blood sugar
- To treat arrhythmias
Correct answer: To lower LDL cholesterol and reduce atherosclerosis risk
Statins inhibit HMG-CoA reductase, reducing LDL cholesterol production and decreasing the risk of atherosclerotic plaque buildup in coronary and other arteries.
ECG Cardiac Pharmacology 1
Which class of medications slows the heart rate by blocking beta-adrenergic receptors?