Second Degree AV Block Type 2 

2nd Degree AZ Block Type 2


OCCURS DUE TO AN INTERMITTENT INTERRUPTION NEAR OR BELOW THE AV JUNCTION. INTERRUPTION IS NOT PROGRESSIVE, BUT OCCURS SUDDENLY AND WITHOUT WARNING!! P WAVES BEFORE EVERY QRS COMPLEX AND ALL ARE THE SAME SIZE AND SHAPE. THIS OCCURS UNTIL A QRS COMPLEX IS DROPPED. THE QRS MAY BE WIDER IF THE BLOCK OCCURS NEAR THE BUNDLE OF HIS. CAN OCCUR IN ANY RHYTHM, OVERALL RHYTHM IS IRREGULAR AND THE HEART RATE VARIES DEPENDING ON THE UNDERLYING RHYTHM.


Characteristics

Rate Atrial rate is greater than ventricular rate. Ventricular rate often slow
Rhythm Atrial regular (P waves plot on time. Ventricular irregular

P-Waves Normal in shape and size; Some P waves are not followed by QRS complex (More P’s than QRS)

PR Interval Within normal limits or slightly prolonged but constant for the conducted beats. There may be some shortening of the PR interval that follows a non-conducted P wave 

QRS Duration 0.11 seconds (almost 2 full boxes) but is periodically absent after P waves


Treatment

Monitor Diagnostic 12 lead
Oxygen 15 LPM NR mask
IV 18g AC

Administer Meds

Atropine 0.5-1 SIVP over 1-2 min Repeat every 3-5 min w/ 3.0mg ma

Dopamine 5-10mcg/kg/min (Diluted Infusion only)

Epinephrine 2-10mcg/min (Diluted Infusion only)

Consider Transcutaneous Pacing


MEDS

Atropine 0.5-1 SIVP over 1-2 min Repeat every 3-5 min w/ 3.0mg max

Dopamine 5-10mcg/kg/min (Diluted Infusion only) 

Epinephrine 2-10mcg/min (Diluted Infusion only) 


Noticeable by: 

Some of the P waves are not followed by a QRS Complex’s


© Matt Dillard 2012