ACLS Heart Blocks

Heart Block

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.