Flashcard Deck: Cardiovascular Drugs (Paramedic-Focused, Week 5)

Which system is dominant in a patient who is anxious, tachycardic, and hypertensive?

Sympathetic Nervous System (SNS)

What are the effects of the Sympathetic Nervous System on the heart?

↑ HR (chronotropy), ↑ contractility (inotropy), ↑ conduction (dromotropy)

What system is dominant in a patient who is bradycardic and hypotensive with high vagal tone?

Parasympathetic Nervous System (PSNS)

What are the effects of the Parasympathetic Nervous System on the heart?

↓ HR, ↓ conduction, ↓ contractility

What ion change is primarily responsible for increased contractility in SNS stimulation?

↑ intracellular calcium (Ca²⁺)

Why might glucagon be used in a patient with beta-blocker overdose presenting with bradycardia and shock?

Provides positive inotropic and chronotropic effects independent of beta receptors

What is the main limitation of glucagon in cardiac use?

Short duration (10-15 minutes) and limited evidence

What is the shock index for a patient with HR 120 and SBP 90?

Shock Index = 120/90 = 1.3 → indicates shock

What are the only two indications for IV cannulation in paramedicine?

Administer fluids, Administer drugs

Why must fluid boluses be reassessed frequently?

Risk of fluid overload → monitor BP, lungs, ICP signs

How much of a 1L crystalloid bolus remains intravascular?

~250 mL

What SpO₂ target should you aim for in a hypoxic COPD patient?

88-92%

Why is hyperoxia dangerous?

Causes reduced perfusion to vital organs

Should oxygen be given to a patient who is SOB but has normal SpO₂?

No—investigate underlying cause

What is the primary mechanism of GTN?

Converts to nitric oxide → ↑ cGMP → ↓ Ca²⁺ → vasodilation

Why does GTN reduce myocardial workload?

Venodilation → ↓ preload → ↓ cardiac work

Why is GTN given sublingually?

Avoids first-pass metabolism (liver inactivates ~90%)

What is a critical contraindication for GTN?

Recent PDE5 inhibitor use (e.g., sildenafil) → severe hypotension

Why must GTN be used cautiously in inferior/RV STEMI?

Risk of severe hypotension due to preload dependence

What are common side effects of GTN?

Headache, Hypotension, Dizziness, Tachycardia

What are the two key components required for clot formation?

Platelets + fibrin

What does aspirin inhibit in clot formation?

Thromboxane A2 (platelet activation)

What is the mechanism of clopidogrel?

Inhibits ADP receptors → prevents platelet activation

What is the role of heparin?

Anticoagulant → inhibits clot formation (secondary haemostasis)

What drug dissolves existing clots in STEMI?

Tenecteplase (fibrinolytic)

What drug promotes clot stability in bleeding?

Tranexamic acid (inhibits fibrinolysis)

What are standard prehospital medications for STEMI?

Oxygen (if hypoxic), Aspirin, GTN, Analgesia

What additional therapies may be used in fibrinolysis strategy?

Clopidogrel, Heparin, Tenecteplase

What class of drug is amiodarone and its effect?

Class III → prolongs action potential and refractory period

What class are beta-blockers in antidysrhythmics?

Class II → β1 blockade

What class are calcium channel blockers in dysrhythmia management?

Class IV → slow AV node conduction

What are the two main effects of digoxin?

↑ contractility (↑ Ca²⁺), ↓ heart rate (vagal effect)

What is the mechanism of digoxin?

Inhibits Na⁺/K⁺ pump → ↑ intracellular Ca²⁺

Why is medication history critical in prehospital cardiac patients?

Identifies diagnosis, Predicts complications, Guides treatment decisions

What is the risk for a hypotensive patient who recently took antihypertensives and receives GTN?

Profound hypotension (additive vasodilation)

What is the key paramedic principle when giving cardiac drugs?

Treat the patient, reassess frequently, and anticipate complications