Coarse Ventricular Fibrillation (V-Fib)
ACLS Resuscitation Interventions & Defibrillator
Chaotic, disorganized ventricular electrical activity (>3mm amplitude). Ventricles are quivering with zero stroke volume and zero cardiac output.
- ✓Immediate CPR (100-120/min, 2-2.4 inches depth)
- ✓Immediate unsynchronized defibrillation @ 200J Biphasic / 360J Monophasic
- ✓Epinephrine 1mg IV/IO every 3-5 min after 2nd shock
- ✓Amiodarone 300mg IV/IO bolus after 3rd shock (or Lidocaine 1-1.5 mg/kg)
Diagnostic Cases (28)
NREMT-PAcute Inferior Wall STEMI
Classic ST elevation in contiguous inferior leads II, III, aVF with reciprocal depression in I, aVL.
Acute Anterior STEMI (LAD Occlusion)
Massive tombstone ST elevation in precordial leads V1-V4. High risk of cardiogenic shock.
Inferior STEMI with Right Ventricular Involvement (V4R+)
ST elevation in II, III, aVF plus ≥1mm ST elevation in lead V4R. Preload dependent!
Isolated Posterior Wall STEMI
ST depression in V1-V3 with tall R waves and upright T waves. Mirror image of anterior elevation!
Wellens Syndrome Type B (Critical LAD Stenosis)
Deeply inverted or biphasic T waves in V2-V3 while PAIN-FREE. Imminent massive anterior MI!
De Winter T Wave Pattern (Hyperacute LAD Occlusion)
J-point ST depression with tall, prominent, symmetric T waves in V1-V6. STEMI equivalent!
Severe Hyperkalemia (Serum K+ 8.2 mEq/L)
Tall, narrow, tented T waves, widened QRS, flattened/absent P waves. Imminent cardiac arrest!
Acute Diffuse Pericarditis
Widespread concave ('saddleback') ST elevation across almost all leads + PR depression. aVR has PR elevation!
LBBB with Sgarbossa Criteria (Concordant STEMI)
Wide QRS (>120ms) with concordant ST elevation ≥1mm in lead V5/V6. High specificity for acute MI!
Complete Right Bundle Branch Block (RBBB)
Wide QRS (≥120ms) with classic rsR' ('rabbit ears') in lead V1-V3 and slurred S wave in leads I, aVL, V5, V6.
Brugada Syndrome Type 1 (Coved ST Elevation)
Coved-type ST elevation ≥2mm in V1-V2 followed by negative T wave. High risk of sudden cardiac arrest!
Monomorphic Ventricular Tachycardia (180 bpm)
Regular wide QRS complex (>140ms) tachycardia. Extreme axis deviation & AV dissociation.
Wolff-Parkinson-White (WPW) Pre-excitation
Short PR interval (<120ms), slurred QRS upstroke (Delta wave), wide QRS. Accessory pathway (Bundle of Kent).
Normal Sinus Rhythm (NSR)
Normal cardiac impulse originating in the SA node at 60-100 bpm with 1:1 AV conduction and normal intervals.
Sinus Bradycardia
Regular sinus impulses occurring at a rate < 60 bpm. Can be normal in athletes or symptomatic in SA node ischemia/disease.
Sinus Tachycardia
Regular sinus rhythm with heart rate > 100 bpm. Secondary response to fever, pain, hypoxia, hypovolemia, or anxiety.
Atrial Fibrillation with RVR
Irregularly irregular rhythm without discrete P waves. Chaotic atrial f-waves at 350-600/min with variable AV conduction.
Atrial Flutter (2:1 Block)
Macro-reentrant right atrial circuit generating classic 'sawtooth' Flutter (F) waves at ~300 bpm with 2:1 AV conduction.
Paroxysmal SVT (AVNRT)
Rapid, regular narrow-complex tachycardia (150-250 bpm) originating above the ventricles with P waves buried or inverted.
Polymorphic VT / Torsades
Polymorphic wide-complex tachycardia with QRS amplitude twisting around the isoelectric line. Preceded by baseline long QTc.
Ventricular Fibrillation (V-Fib)
Completely disorganized, chaotic ventricular electrical activity without recognizable QRS complexes or pulse. Immediate CPR & Defibrillation!
First-Degree AV Block
Fixed, prolonged PR interval (>200 ms / 5 small boxes) with 1:1 AV conduction and normal QRS.
Second-Degree AV Block Mobitz I
Progressive PR interval prolongation until a P wave is completely unconducted (dropped QRS). Grouped beating.
Second-Degree AV Block Mobitz II
Constant PR intervals with sudden non-conducted P waves (dropped QRS complexes). High risk of progression to Complete Block!
Third-Degree (Complete) Block
Complete electrical dissociation between atria and ventricles (P-P and R-R intervals regular but completely independent).
Ventricular Asystole (True Cardiac Standstill)
Complete absence of ventricular electrical and mechanical activity across all 12 leads. Pulseless cardiac arrest.
Pulseless Electrical Activity (PEA) - Severe Bradycardia
Organized electrical activity on monitor screen (32 BPM) in a patient with NO palpable carotid or femoral pulse.
Fine Ventricular Fibrillation (<2mm Amplitude)
Low-amplitude chaotic fibrillatory wavelets (<2mm). Critical to differentiate from true asystole by checking orthogonal leads.
Acute Inferior Wall STEMI
Continuous Lead II Rhythm Strip
= 192 ms
Bundle Branch Block (LBBB/RBBB), IVCD, or Ventricular Rhythm
Acute Inferior Myocardial Infarction
Patient Clinical Presentation
Chief Complaint: Substernal chest pressure radiating to jaw and epigastrium, ongoing 45 minutes.
Lead II Clinical Findings
★ Culprit Ischemic LeadLead II Clinical Significance: Monitors the Inferior Wall (Right Coronary Artery / RCA). Shows primary ST elevation and active vector depolarization changes indicative of Acute Inferior Myocardial Infarction.
Anatomical Territory: Inferior Wall of Left Ventricle
Reflects electrical mirror vector opposite the ischemia site.
Pathophysiology & ECG Diagnostic Criteria
Acute thrombotic occlusion of the Right Coronary Artery (RCA). The inferior wall leads (II, III, aVF) directly face the epicardial injury vector resulting in ST elevation, while high lateral leads (I, aVL) view the reciprocal vector as ST depression.
- ST elevation ≥1 mm (0.1 mV) in at least two anatomically contiguous inferior leads (II, III, aVF).
- Reciprocal ST depression in Lead I and aVL.
- Lead III ST elevation > Lead II ST elevation strongly favors RCA occlusion over LCx.
Paramedic Protocol Actions
- Transmit 12-Lead EKG to Medical Control / STEMI Receiving Center immediately.
- Administer Aspirin 324 mg PO chewed (if no allergy).
- Obtain Right-Sided 12-Lead EKG (Lead V4R) to rule out Right Ventricular Infarction BEFORE administering Nitroglycerin.
- Administer O2 only if SpO2 < 90% or patient in respiratory distress.
- Establish 2x large-bore IV access.
Critical Paramedic Contraindications
- Avoid Nitroglycerin & Morphine if Right Ventricular Involvement (V4R+) or SBP < 90 mmHg.
EKG Rhythm Library (28)
Every scenario, grouped by clinical rhythm category.
Acute Inferior Wall STEMI
Classic ST elevation in contiguous inferior leads II, III, aVF with reciprocal depression in I, aVL.
Acute Anterior STEMI (LAD Occlusion)
Massive tombstone ST elevation in precordial leads V1-V4. High risk of cardiogenic shock.
Inferior STEMI with Right Ventricular Involvement (V4R+)
ST elevation in II, III, aVF plus ≥1mm ST elevation in lead V4R. Preload dependent!
Isolated Posterior Wall STEMI
ST depression in V1-V3 with tall R waves and upright T waves. Mirror image of anterior elevation!
Wellens Syndrome Type B (Critical LAD Stenosis)
Deeply inverted or biphasic T waves in V2-V3 while PAIN-FREE. Imminent massive anterior MI!
De Winter T Wave Pattern (Hyperacute LAD Occlusion)
J-point ST depression with tall, prominent, symmetric T waves in V1-V6. STEMI equivalent!
Severe Hyperkalemia (Serum K+ 8.2 mEq/L)
Tall, narrow, tented T waves, widened QRS, flattened/absent P waves. Imminent cardiac arrest!
Acute Diffuse Pericarditis
Widespread concave ('saddleback') ST elevation across almost all leads + PR depression. aVR has PR elevation!
LBBB with Sgarbossa Criteria (Concordant STEMI)
Wide QRS (>120ms) with concordant ST elevation ≥1mm in lead V5/V6. High specificity for acute MI!
Complete Right Bundle Branch Block (RBBB)
Wide QRS (≥120ms) with classic rsR' ('rabbit ears') in lead V1-V3 and slurred S wave in leads I, aVL, V5, V6.
Brugada Syndrome Type 1 (Coved ST Elevation)
Coved-type ST elevation ≥2mm in V1-V2 followed by negative T wave. High risk of sudden cardiac arrest!
Monomorphic Ventricular Tachycardia (180 bpm)
Regular wide QRS complex (>140ms) tachycardia. Extreme axis deviation & AV dissociation.
Wolff-Parkinson-White (WPW) Pre-excitation
Short PR interval (<120ms), slurred QRS upstroke (Delta wave), wide QRS. Accessory pathway (Bundle of Kent).
Normal Sinus Rhythm (NSR)
Normal cardiac impulse originating in the SA node at 60-100 bpm with 1:1 AV conduction and normal intervals.
Sinus Bradycardia
Regular sinus impulses occurring at a rate < 60 bpm. Can be normal in athletes or symptomatic in SA node ischemia/disease.
Sinus Tachycardia
Regular sinus rhythm with heart rate > 100 bpm. Secondary response to fever, pain, hypoxia, hypovolemia, or anxiety.
Atrial Fibrillation with RVR
Irregularly irregular rhythm without discrete P waves. Chaotic atrial f-waves at 350-600/min with variable AV conduction.
Atrial Flutter (2:1 Block)
Macro-reentrant right atrial circuit generating classic 'sawtooth' Flutter (F) waves at ~300 bpm with 2:1 AV conduction.
Paroxysmal SVT (AVNRT)
Rapid, regular narrow-complex tachycardia (150-250 bpm) originating above the ventricles with P waves buried or inverted.
Polymorphic VT / Torsades
Polymorphic wide-complex tachycardia with QRS amplitude twisting around the isoelectric line. Preceded by baseline long QTc.
Ventricular Fibrillation (V-Fib)
Completely disorganized, chaotic ventricular electrical activity without recognizable QRS complexes or pulse. Immediate CPR & Defibrillation!
First-Degree AV Block
Fixed, prolonged PR interval (>200 ms / 5 small boxes) with 1:1 AV conduction and normal QRS.
Second-Degree AV Block Mobitz I
Progressive PR interval prolongation until a P wave is completely unconducted (dropped QRS). Grouped beating.
Second-Degree AV Block Mobitz II
Constant PR intervals with sudden non-conducted P waves (dropped QRS complexes). High risk of progression to Complete Block!
Third-Degree (Complete) Block
Complete electrical dissociation between atria and ventricles (P-P and R-R intervals regular but completely independent).
Ventricular Asystole (True Cardiac Standstill)
Complete absence of ventricular electrical and mechanical activity across all 12 leads. Pulseless cardiac arrest.
Pulseless Electrical Activity (PEA) - Severe Bradycardia
Organized electrical activity on monitor screen (32 BPM) in a patient with NO palpable carotid or femoral pulse.
Fine Ventricular Fibrillation (<2mm Amplitude)
Low-amplitude chaotic fibrillatory wavelets (<2mm). Critical to differentiate from true asystole by checking orthogonal leads.
Acute Inferior Myocardial Infarction
Heart Rate & Rhythm
72 BPM
Regular
P-Wave Morphology
Normal upright P wave
PR Interval
120 - 200 ms
QRS Duration
80 - 110 ms
Anatomical Origin Site
Inferior Wall of Left Ventricle
= 192 ms
Bundle Branch Block (LBBB/RBBB), IVCD, or Ventricular Rhythm
Diagnostic Criteria & Clinical Physiology
Acute thrombotic occlusion of the Right Coronary Artery (RCA). The inferior wall leads (II, III, aVF) directly face the epicardial injury vector resulting in ST elevation, while high lateral leads (I, aVL) view the reciprocal vector as ST depression.
- ST elevation ≥1 mm (0.1 mV) in at least two anatomically contiguous inferior leads (II, III, aVF).
- Reciprocal ST depression in Lead I and aVL.
- Lead III ST elevation > Lead II ST elevation strongly favors RCA occlusion over LCx.
Paramedic Emergency Field Protocol & ACLS Actions
- Transmit 12-Lead EKG to Medical Control / STEMI Receiving Center immediately.
- Administer Aspirin 324 mg PO chewed (if no allergy).
- Obtain Right-Sided 12-Lead EKG (Lead V4R) to rule out Right Ventricular Infarction BEFORE administering Nitroglycerin.
- Administer O2 only if SpO2 < 90% or patient in respiratory distress.
- Establish 2x large-bore IV access.
NREMT 12-Lead Clinical Simulation
Read each patient's 12-lead, pick the primary diagnostic finding, and select the affected leads.
A case counts as correct when both the diagnosis and every affected lead are right.
Coronary Artery Lead Mapping Guide
Anatomical lead placement and the corresponding coronary vascular territories.
Culprit vessel: RCA (Right Coronary Artery) in 80-85% of cases; LCx in 15%.
High risk of bradycardia and AV blocks. Always check Right-Sided Lead V4R to rule out RV infarction!
Culprit vessel: LAD (Left Anterior Descending - Septal Branches).
Interventricular septum involvement; watch for bundle branch blocks.
Culprit vessel: LAD (Left Anterior Descending - Diagonal Branches).
High mortality rate ("Widowmaker"). High incidence of cardiogenic shock and heart failure.
Culprit vessel: LCx (Left Circumflex) or Diagonal LAD.
High lateral leads (I, aVL) often show subtle elevation prior to extensive infarction.