ECG Interp Criteria

Right Atrial Enlargement

• P-Pulmonale

• Peaked P waves

• P-waves over 2.5mm in lead II

Pericarditis

• Global notched ST elevation with no reciprocal changes

• PR depression (downsloping)

• PR elevation in AVR

Early Repolarization

• Notched ST elevation

• typically only in precordial leads

Dextrocardia

• Limb lead reversal pattern

• Absent R-wave progression

Electrical Alternans

• Alternating Amplitude (height) of QRS complex

Hypothermia

• J/Osborne waves

• Slow HR

• Sometimes shiver artifact

Digoxin Effect

• Not necessarily Digoxin toxicity

• Scooping of ST segment

• usually seen in A-Fib

• Usually slow HR

Raised Intracranial Pressure and Subarachnoid Hemorrhage

• Broad T-wave inversion

• Often prolonged QT segment

Incomplete Right Bundle Branch Block

• RSR’ pattern (bunny ears) in V1

• QRSD 0.10-0.11 sec

Brugada Pattern

• IRBBB pattern

• ST elevation in V1 and V2

• Type 1 = cove

• Type 2 = saddleback

Right Ventricular Hypertrophy

• RAD

• Tall R in V1

• Deep S in V5/V6

Left Atrial Enlargement

• P-wave longer than 0.12 sec in lead II

• P-mitral

• Biphasic P wave in V1

Left Ventricular Hypertrophy

• Sokolow-Lyon: S wave in V1/V2 + R wave in V5/V6 = 35mm or more

• R wave in AVL 11mm or more

• LAD

• Strain Pattern

RVH Strain Pattern

• ST depression

• T wave inversion

• Usually seen in V1-V3

LVH Strain Pattern

• ST depression

• T wave Inversion

• Usually in V5, V6, AVL, I

Left Bundle Branch Block

• QRSD 0.12sec or longer

• Tall R in lead I, V5, V6

• Deep S wave in V1

• No Q wave in lateral leads

First Degree AV Block

• PRI 0.20 sec or longer

• 1 P wave for every QRS complex

Ischemia

• T wave inversion

• Symmetrical T wave

• ST depression

Pulmonary Embolism

• Sinus tachycardia (elevated HR)

• S1Q3T3 pattern

• RAD

• RV stain pattern

• RBBB possible

Infarction

• Pathological Q-wave

Injury

• ST elevation

Hypercalcemia

• Shortened ST segment

Hypocalcemia

• Prolonged QT with no U wave

• Prolonged ST segment

Right Bundle Branch Block

• QRSD 0.12 sec or longer

• RSR’ (bunny ears) in V1

• Wide S in lead I and V6

Incomplete Left Bundle Branch Block

• LBBB morphology

• QRSD 0.10-0.11 sec

Third Degree AV Block

• Complete AV dissociation

• P-waves march through QRS complexes

• No fixed PRI

Mobitz II

• Constant PRI

• Sudden dropped QRS complex

• memory trick… If some P’s don’t get through = Mobitz II

Ventricular Escape Beat

• Late beat

• Wide QRS

• No P waves

• Occurs after a pause

Fixed Ratio AV Block

• Every 2nd/3rd/… P wave is blocked

• 2/3/.. P waves for every QRS complex

Mobitz I / Wenckebach

• PRI gest progressively longer

• Eventually QRS is dropped (pause)

• Pattern Repeats

Ventricular Fibrillation

• Chaotic rhythm

• No P waves

• No QRS complexes

• No measureable rate

Ventricular Tachycardia

• Rate over 100 bpm

• Wide QRS (longer than 0.12 sec)

• Regular Rhythm

• Capture or fusion beats may occur

• AV dissocation

Accelerated Idioventricular Rhythm

• Rate 40-100 bpm

• Wide QRS

• Often reperfusion rhythm

Ventricular Rhythm

• Rate 20-40 bpm

• Wide QRS

• no relationship to P wave

PVC

• early beat

• no preceding P wave

• wide, bizarre QRS

• QRSD 0.12sec or longer

• full compensatory pause

AVNRT

• Regular narrow tachycardia

• rate 150-250

• P waves buried in QRS

• retrograde P waves possible

PJC

• Premature beat

• P wave is absent or inverted

• QRS narrow

• usually has compensatory pause

SVT

• rate 150-250

• regular rhythm

• narrow QRS complex

• P wave is absent (hidden)

Junctional Escape Rhythm

• Rate 40-60bpm

• P wave absent (high)

• P wave inverted (mid)

• Retrograde P wave (low)

• Narrow QRS complex

• “accelerated junctional” if 60-100bpm

• “Junctional tachycardia” if over 100bpm

Atrial Fibrillation

• No P waves

• Fibrillatory baseline

• Irregularly irregular

• variable ventricular rate

Atrial Flutter

• Sawtooth flutter waves

• atrial rate 250-350bpm

• ventricular rate depends on conduction

Multifocal Atrial Tachycardia

• Rate over 100bpm

• 3 or more P wave morphologies

• irregular rhythm

• WAP + Tachy

Wandering Atrial Pacemaker

• Rate less than 100 bpm

• 3 or more P wave morphologies

• Irregular rhythm

PAC

• early beat

• abnormal P wave

• QRS usually normal

• non-compensatory pause

Aberrant Conduction

• Supraventricular

• conducted through bundle branch during refractory period

• wide QRS

• usually RBBB appearance

• Seen with PAC, A-Flutter, A-Fib and SVT

Capture Beat

• One normal QRS complex during VT

• More narrow than other QRS complexes

Ashman’s Phenomenon

• Long R-R followed by short R-R

• aberrantly conducted supraventricular beat

• usually RBBB morphology

• common in A-Fib

Wolf-Parkinson-White Syndrome

• PRI 0.12 sec or longer

• Delta waves present

• wide QRS complex

Left Posterior Hemiblock

• RAD with no other cause

Left Anterior Hemiblock

• LAD with no other cause