SVT and A-flutter:               Start with 50 J Monophasic defibrillator only: 0.5-1.0 J/kg, increase to 2 J/kg if lower dose ineffective
Other regular tachy rhythms: Start with 100 J, then 120, 150, and 200 (biphasic defibrillator)

Rhythm Interpretation, QRS Complex

The QRS Complex

Normal  0.06 to 0.10 seconds (1.5 to 2.5 small boxes)
Narrow  < 0.06 seconds Not usually indicative of a problem
Wide  >0.12 seconds Consider ventricular rhythm or bundle branch block, especially if the complex is notched, like “rabbit ears”

Rhythm Interpretation, PR Interval

The PR Interval

Normal  0.12 to 0.20 seconds (3 to 5 small boxes)
Short  < 0.12 seconds Consider junctional rhythm
Long  > 0.20 seconds If consistent, consider 1st degree AV block
Irregular Progressive lengthening until one QRS complex is dropped: consider 2nddegree AV block Type I/WenckebachConsistent, and normal, but some P waves are not followed by a QRS complex: consider 2nddegree AV block Type IIInconsistent and P waves unrelated to QRS complexes: consider 3rd degree AV block/complete heart block

Rhythm Interpretation, The Basics

1. Find the RATE.

2. Is the RHYTHM regular or irregular?

3. Are P WAVES present and one-to-one with the QRS complexes?

4. Is the QRS normal or wide (>0.12 sec/>3 small boxes)?

5. Any EXTRA beats or anomalies?

Small boxes are 0.04 sec each. One large box is 0.2 sec (contains 5 small boxes).

ECG/EKG Parameters

Normal Rate (SA node) 60-100 bpm
Junctional Default 40-60 bpm
Ventricular Default 20-40 bpm
Bradycardia (SB) < 60 bpm
Tachycardia (ST) > 100 bpm
QRS Interval 0.06-0.10 seconds (1.5-2.5 small boxes)
PR interval 0.12-0.20 seconds (3-5 small boxes)

ECG/EKG Abbreviations

NSR normal sinus rhythm
ST sinus tachycardia
SB sinus bradycardia
SVT supraventricular tachycardia
PSVT paroxysmal supraventricular tachycardia
A-fib atrial fibrillation
A-flutter atrial flutter
VT ventricular tachycardia
VF ventricular fibrillation
PAC premature atrial complex
PJC premature junctional complex
PVC premature ventricular complex
SA node sino-atrial node