Study sheet: Cardiac Pharmacology and Diagnostics

Cardiac Medications, Diagnostics, and Clinical Concepts Revision Sheet

1. 📌 Essentials

• Nitroglycerin: Vasodilator for angina relief, sublingual route. Aspirin (ASA): Antiplatelet, prevents clot growth in MI.
• Thrombolytics (tPA): Dissolve clots, must be administered within 3-4.5 hours of stroke.
• Anticoagulants: Warfarin (INR 2-3), HeparinaPTT), prevent stroke/DVT/PE.
• Statins: Lower LDL cholesterol, reduce atherosclerosis risk.
• EKG: ST elevation indicates STEMI; T wave inversions suggest ischemia.
• Lung sounds: Crackles (fluid), wheezes (narrowed airways), rhonchi, stridor.
• Hypertension stages: Normal (<120/80), Elevated (120-129/<80), Stage 1 (130-139/80-89), Stage 2 (≥140/90).
• Pulse points: Radial, carotid, brachial, femoral, popliteal, dorsalis pedis, posterior tibial.
• Cardiac emergency drugs: Nitroglycerin, aspirin, thrombolytics, epinephrine, atropine.

2. 🧩 Key Structures & Components

• Coronary arteries — supply blood to the heart muscle.
• Myocardium — heart muscle tissue responsible for contraction.
• Valves (mitral, tricuspid, aortic, pulmonary) — regulate blood flow direction.
• Conduction system — SA node, AV node, bundle of His, Purkinje fibers.
• EKG leads — record electrical activity from different heart regions.
• Pulse points — accessible sites for assessing circulation.

3. 🔬 Functions, Mechanisms & Relationships

• Nitroglycerin → Vasodilation → Decreases myocardial oxygen demand.
• Aspirin → Platelet inhibition → Prevents clot extension.
• tPA → Clot breakdown → Restores blood flow in ischemic stroke/MI.
• Warfarin/Heparin → Anticoagulation → Prevent thrombus formation.
• EKG → Detects electrical activity → Identifies ischemia, infarction, arrhythmias.
• Lung sounds → Diagnostic clues → Fluid (crackles), airway narrowing (wheezes).
• Blood pressure → Affects cardiac workload → Hypertension increases risk of MI/stroke.
• Pulse points → Reflect peripheral perfusion → Used to assess circulatory status.

4. Comparative Table

Item	Key Features	Notes / Differences
Nitroglycerin	Vasodilator, sublingual, relieves angina	Rapid onset, monitor BP
Aspirin	Antiplatelet, 160-325 mg, inhibits platelet aggregation	Used early in MI
tPA	Clot-dissolving, time-sensitive (3-4.5 hrs window)	Contraindicated in hemorrhagic stroke
Warfarin	Oral, INR 2-3, requires regular monitoring	Long-term anticoagulation
Heparin	IV/subcutaneous, monitored via aPTT	Quick onset, used in hospital settings
Statins	Lower LDL, reduce atherosclerosis	Lipid-lowering agents
Midodrine	Vasoconstrictor, treats hypotension	Dose titration needed

5. 🗂️ Hierarchical Diagram

Cardiac Pharmacology
 ├─ Vasodilators
 │    ├─ Nitroglycerin
 │    └─ Hydralazine
 ├─ Antiplatelets
 │    └─ Aspirin
 ├─ Thrombolytics
 │    └─ tPA
 ├─ Anticoagulants
 │    ├─ Warfarin
 │    └─ Heparin
 └─ Lipid-lowering agents
      └─ Statins

6. ⚠️ High-Yield Pitfalls & Confusions

• Confusing Nitroglycerin with Ca Channel Blockers — different mechanisms.
• Mistaking ST elevation for ST depression; indicates infarction vs. ischemia.
• Overlooking contraindications for thrombolytics (e.g., recent surgery, bleeding).
• Misinterpreting lung sounds: crackles vs. wheezes.
• Assuming all hypertension is "stage 2"; always check BP classification.
• Confusing Warfarin (INR 2-3) with Heparin (aPTT monitoring).
• Ignoring the time window for tPA administration.
• Using pulse points incorrectly for circulation assessment.

7. ✅ Final Exam Checklist

• Know the indications, routes, and key features of Nitroglycerin.
• Recognize the role and dosage of Aspirin in MI.
• Understand the time window and contraindications for tPA.
• Be familiar with Warfarin (INR target) and Heparin (aPTT).
• Identify lung sounds: crackles, wheezes, rhonchi, stridor.
• Classify blood pressure: normal, elevated, stage 1, stage 2.
• Know the main pulse points and their clinical significance.
• Recognize EKG patterns: ST elevation, T wave inversion.
• List emergency drugs: Nitroglycerin, aspirin, thrombolytics, epinephrine, atropine.
• Understand the hierarchy of cardiac pharmacology and their mechanisms.
• Be aware of common pitfalls in interpretation and management.
• Recall the anatomy of coronary arteries and conduction system.
• Be able to interpret basic EKG strips and lung sounds.
• Know the clinical relevance of each medication and diagnostic tool.

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