ECG rhythms

steps of systematic ECG interpretation

1. regularity (R-R and P-P)

2. Rate ( 6 sec or 1500)

3. P waves

4. 4. PR interval

5. QRS

6. ST and T wave changes

7. Interpret the rhythm

8. Determine management

P wave normal

• 2.5mm tall or less

• 0.12 or less

PR interval

• 0.12-0.20 sec Normal

• Less than 0.12 ectopic near AV node

• More than 0.20 AV delay

Normal QRS

• 0.11 or less

• 0.12 or more ventricular origin or abnormal conduction

define sinus rhythm

• starts in the SA node

• P before every QRS

• PR 0.12-.20

Normal sinus rhythm

everything normal

Sinus Bradycardia

• Rate less that 60

• normal complex just slower

Sinus tachycardia

• Rate over 100

• starts and ends gradually

Sinus arrhythmia

• rate 60-100 irregular

• R-R shortens on inspiration

• longer on expiration

SA block

• irregular rate

• missing PQRST is the same or multiple of the P-P interval

Sinus arrest

• irregular rate with a pause of undetermined length

• pause not a multiple of the p-p interval

Premature Atrial Complex

• rate varies and is irregular

• Early P wave, shape is different

  • biphasic

  • nitched

  • pointed

Early beat with odd P wave

Wandering Atrial pacemaker

Pacemaker shifts btw SA node, Atria AV junction

• Rate is irregular 60-100BPM

• at least 3 different P waves shapes

Atrial Tachycardia

3 or more PACs in a row, rate over 100

Atrial fibrillation

• partial rate 300-600

• ventricular is variable

• no P wave, wavy baseline

Atrial Flutter

• atrial rate 240-300

• ventricular usually <180

• sawtooth flutter

Premature Junctional complex

• irregular rate (early beats)

• hidden of inverted P

Junctional escape rhythm

• rate 40-60 BPM

• appears late, after a pause

accelerated junctional rhythm

• 60-100BPM

• P wave is missing/ inverted

Junctional tachycardia

• Rate 100-180

• 3 or more PJCs over a 100bpm