Normal P-R interval is .12-.20 secs NBD
each square is .04 seconds so normal is between 3 – 5 squares
1st degree is >.20 ie >5 small squares
2nd degree Type 1 = Wenkebach
2nd Degree Type 2 Some p waves are associated with QRS and some are not eg 3:1 ratio is 3 p waves and only 1 QRS
The p-r interval may be normal It is the intermittent drop of a QRS complex
Could be for example 3 p waves before a qrs and when that QRS comes it is normal
3rd degree No relationship between the p wave and QRS
P waves are regular and QRS are regular but live and function independently
If hypotensive Transcutaneous pacing
The adult pads are placed and transcutaneous pacing is initiated. Thetranscutaneous pacer is set for 70 PPM at 50 mA. Pacing spikes are visible with what appear to be large, corresponding QRS complexes.