How's your 12 lead knowledge? I've been hearing from a lot of students that these topics are a must know on your national. Bipolar Leads (Leads I, II, III) What they are: Measure electrical activity between two electrodes The 3 Bipolar Leads - Lead I → Right arm → Left arm - Lead II → Right arm → Left leg - Lead III → Left arm → Left leg What they show: - Frontal plane view of the heart High-Yield Associations - Lead II → most commonly used for rhythm monitoring - Leads II, III, aVF → inferior wall NREMT Pearl: Bipolar leads = limb-to-limb electrical comparison Augmented Leads (aVR, aVL, aVF) What they are: Measure electrical activity from one positive electrode looking toward the heart The Key Augmented Leads - aVF → looks at inferior wall - aVL → looks at lateral wall - aVR → generally not used for localization (but clinically important in some cases) High-Yield Associations - Inferior leads → II, III, aVF - High lateral leads → I, aVL NREMT Pearl: aVF = feet → inferior heart When to Check a V4R (Right-Sided ECG) Indication: Inferior STEMI Why? - Inferior MIs can involve the right ventricle What V4R tells you: - Confirms right ventricular infarction Why this matters Right-sided MI patients are: - Preload dependent Clinical Impact - ❌ Avoid nitrates (can cause severe hypotension) - ✔️ Give fluids to maintain preload NREMT Pearl: Inferior MI → check V4R before giving nitro Reciprocal Changes What they are: ST depression in leads opposite the area of infarction Why they matter: - Help confirm true STEMI - Increase diagnostic accuracy MUST KNOW PATTERNS Inferior MI - ST elevation: II, III, aVF - Reciprocal depression: I, aVL Lateral MI - ST elevation: I, aVL, V5, V6 - Reciprocal depression: II, III, aVF Posterior MI - V1–V3 depression = posterior involvement NREMT Pearl: ST elevation in one area → look for depression opposite Delta Wave What it is: Slurred upstroke at the beginning of the QRS complex

Causes of "Erythematous skin" Erythema = vasodilation/inflammation. On exams, they love pattern recognition: - Infectious: cellulitis, scarlet fever, meningococcemia (may start as erythema), & viruses - Allergic/immune: urticaria, anaphylaxis, contact dermatitis, drug eruptions - Heat/vasodilatory: heat illness, fever/flushing, sunburn - Toxicologic: CO exposure (classically “cherry red” is unreliable), niacin flush, anticholinergic vs sympathomimetic syndromes (often flushed) - Shock/inflammatory states: early sepsis (warm, flushed) - Autoimmune: lupus rash, dermatomyositis, vasculitis Pearl: Erythema + hypotension/wheeze/angioedema = anaphylaxis until proven otherwise.

Seizures = abnormal electrical activity in the brain Tonic-Clonic (Grand Mal) What it is: Most recognizable seizure type Phases (MEMORIZE) - Tonic phase → stiffening - Clonic phase → rhythmic jerking - Postictal → confusion, fatigue Presentation - Loss of consciousness - Full-body convulsions - Possible incontinence EMS Management - Protect airway - Oxygen - Benzodiazepines (per protocol) - Check glucose NREMT Pearl: Actively seizing = treat immediately Febrile Seizures What it is: Seizures in children caused by rapid rise in fever Presentation - Pediatric patient - Fever present - Generalized seizure Key Point - Usually self-limiting and benign NREMT Pearl: Child + fever + seizure = febrile seizure Absence Seizures (Petit Mal) What it is: Brief interruption in consciousness Presentation - “Staring spells” - No postictal phase - Patient resumes activity immediately NREMT Pearl: Brief stare, no confusion = absence seizure Meningitis What it is: Inflammation of the meninges (often infectious) Transmission - Spread via respiratory droplets Classic Signs & Symptoms (MEMORIZE) - Fever - Headache - Neck stiffness - Altered mental status - Irritability - Possible rash Special Signs Brudzinski’s Sign - Neck flexion → hips and knees flex Kernig’s Sign - Hip flexed → cannot fully extend leg Life Threat: - Can progress rapidly to sepsis and death EMS Management - PPE (droplet precautions) - Oxygen - Rapid transport NREMT Pearl: Fever + stiff neck + altered = meningitis Parkinson’s Disease What it is: Neurodegenerative disorder Key Pathophysiology Low dopamine in the brain Presentation (MEMORIZE) - Tremor (resting) - Rigidity - Bradykinesia (slow movement) - Postural instability NREMT Pearl: Parkinson’s = low dopamine → slow, rigid movement Wernicke Encephalopathy What it is: Neurologic disorder from vitamin B1 (thiamine) deficiency Common in: - Chronic alcohol use

Sickle Cell Disease What it is: Genetic disorder causing abnormal hemoglobin → RBCs become rigid and sickle-shaped Why it matters: - Sickled cells block blood flow → ischemia and pain - Repeated infarction damages organs High-Yield Complication Splenic infarction → increased infection risk The spleen can also enlarge and rupture (splenic sequestration crisis) Presentation - Severe pain (vaso-occlusive crisis) - Fever (infection risk) - Signs of anemia EMS Management - Oxygen - Pain control - IV fluids - Treat infections early NREMT Pearl: Sickle cell → think spleen + infection risk Marfan Syndrome What it is: Connective tissue disorder affecting fibrillin Key Features (MEMORIZE) - Tall, thin body habitus - Long extremities - Joint laxity Why it matters (CRITICAL) Weak connective tissue → aortic dilation → risk of dissection NREMT Pearl: Marfan = risk for aortic dissection Aortic Dissection What it is: Tear in the inner layer of the aorta → blood separates vessel layers Classic Presentation (MEMORIZE) - Sudden, severe chest pain - “Tearing” or “ripping” pain - Radiates to the back Additional Clues - Unequal blood pressures between arms - Pulse deficits Life Threat: - Rapid internal bleeding → death EMS Management - Control BP (per protocol) - Oxygen - Rapid transport NREMT Pearl: Tearing chest pain to the back = dissection Leukemia & Infection Risk What it is: Cancer of blood-forming tissues → abnormal WBC production Why patients get more infections: Bone marrow produces immature/nonfunctional white blood cells Result: - Poor immune response - High susceptibility to infection NREMT Pearl: Leukemia ≠ strong immune system → high infection risk Blood Transfusion Reactions Overview: Reactions can occur during or shortly after transfusion Common Types Febrile Reaction - Fever - Chills Allergic Reaction - Rash - Itching - Urticaria Hemolytic Reaction (MOST SERIOUS) - Fever - Back pain - Hypotension - Hemoglobin breakdown

Compartment Syndrome vs Crush Injury Compartment Syndrome What it is: Increased pressure within a closed muscle compartment → decreased perfusion → tissue ischemia Classic Signs (6 P’s – MEMORIZE) - Pain (out of proportion, early sign) - Pallor - Paresthesia - Paralysis (late) - Pulselessness (late) - Poikilothermia (cool limb) Key Concept: This is a localized limb emergency EMS Management - Remove constrictive items (splints, bandages) - Keep limb at heart level (not elevated high) - Rapid transport NREMT Pearl: Severe pain out of proportion = compartment syndrome Crush Injury What it is: Prolonged compression of muscle → release of toxins when pressure is removed Life Threat: - Hyperkalemia → lethal dysrhythmias Presentation - History of prolonged entrapment - Weakness - Dysrhythmias after release EMS Management (CRITICAL) - IV fluids BEFORE extrication - Cardiac monitoring - Treat hyperkalemia per protocol NREMT Pearl: Crush injury kills through hyperkalemia, not just trauma Esophageal Emergencies Boerhaave Syndrome What it is: Full-thickness rupture of the esophagus from forceful vomiting Presentation (HIGH-YIELD) - Severe chest pain after vomiting - Subcutaneous emphysema (air under skin) - Rapid deterioration Life Threat: - Mediastinitis → sepsis → death EMS Management - Oxygen - Treat for shock - Rapid transport NREMT Pearl: Vomiting + chest pain + crepitus = Boerhaave syndrome Mallory-Weiss Tear What it is: Partial tear of the esophageal lining from vomiting Presentation - Vomiting followed by bright red blood - Usually less severe than Boerhaave Key Difference: - NOT full rupture - Less likely to cause shock NREMT Pearl: Vomiting + bleeding but stable = Mallory-Weiss Esophageal Varices What it is: Dilated veins in the esophagus (usually from liver disease/cirrhosis) Life Threat: - Massive upper GI hemorrhage Presentation (MEMORIZE) - Large amounts of bright red hematemesis - Signs of shock - History of liver disease/alcohol use