Page 102 - Critical Care Notes

4223_Tab02_045-106 29/08/14 10:00 AM Page 96

CV

Normal Cardiac Rhythm Parameters

NSR • 60–100 bpm
Bradycardia • <60 bpm; consider sinus bradycardia, AV block
Tachycardia • >100 bpm; consider atrial fibrillation, atrial flutter,
supraventricular tachycardia, ventricular tachycardia
PR interval • 0.12–0.20 sec
• >0.20 sec; consider AV block
• <0.12 sec; consider junctional rhythm
• Unable to determine; consider atrial arrhythmia, junc-
tional arrhythmia; examine QRS to determine whether
ventricular arrhythmia
P wave • Generally round
• Saw toothed → consider atrial flutter
• Spiked, nonrounded; consider atrial fibrillation or PACs
QRS • 0.06–0.10 sec
• Wide, bizarre; consider PVC, VT
If baseline is grossly irregular with no discernible P waves, consider VT. Flat
baseline, asystole; begin CPR for either dysrhythmia.

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