ECG (main)

This page is for adult patients. For pediatric patients, see: ECG (peds)

Measurement

All these measures are valid for the standard paper speed of 25 mm/Sec

• 1 small box = 1mm = 0.04 sec = 40 miliseconds
• 5 small boxes = 1 big box = 5mm = 0.2 sec = 200 miliseconds
• Standard 12 lead ECG duration = 10 seconds

Interval	Time(s)	Boxes
PR	0.12 - 0.20	3-5
QRS	0.06 - 0.10	1.5-2.5
QTc	<0.44	N/A

Primary Analysis

• ECG Rhythms
• ECG Axis
• Low ECG voltage

Segments & Intervals

Conduction system of the heart.

• ST Elevation
• ST Depression
• QT Prolongation

Waves

• Q Waves
• T Waves
• R-wave in V1
• Wide QRS

Hypertrophy/Enlargement

Cardiac Hypertrophy and Enlargement

• Right atrial enlargement
• Left atrial enlargement
• Left ventricular hypertrophy
• Right ventricular hypertrophy

Differential includes ischemic events, electrolyte abnormalities, and medication overdoses in addition to rheumatologic conditions

• Anterior MI
• Rheumatic fever
• Myocarditis
• Lyme disease
• Lenegre's disease
• Lev's disease
• SLE
• Systemic sclerosis
• Amyloidosis
• Hemochromatosis
• Sarcoidosis
• Hyperkalemia
• Toxicology
  • Beta blocker toxicity
  • Calcium channel blocker toxicity
  • Digoxin toxicity
  • Amiodarone

Types of second degree AV block

AV blocks

• First degree AV block
• Second degree
  • Second degree AV block type I (Wenkebach)
  • Second degree AV block type II
• Third degree AV block
• AV dissociation without complete heart block

Bundle and Fascicular Blocks

• Right Bundle Branch Block
• Left Bundle Branch Block
• Left Anterior Fascicular Block
• Left Posterior Fascicular Block
• Trifascicular Block

Premature Beats

• Premature atrial contraction
• Premature junctional complex
• Premature ventricular contraction

See Also

• ACS - Anatomical Correlation
• ECGs by Diagnosis
• STEMI equivalents
• Early Repolarization

External Links

• DDxOf: ECG Guide

Videos

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