Second Degree Heart Block- Type 2
Second-Degree (AV) Heart Block (Type 2)
Also called Mobitz II or Hay is a disease of the electrical conduction system of the heart. Second-degree AV block (Type 2) is almost always a disease of the distal conduction system located in the ventricular portion of the myocardium.
This rhythm can be recognized by the following characteristics:
- nonconducted p-waves (electrical impulse conducts through the AV node but complete conduction through the ventricles is blocked, thus no QRS)
- P-waves are not preceded by PR prolongation as with second-degree AV block (Type 1)
- fixed PR interval
- The QRS complex will likely be wide click here to see why»
Second-degree AV block (Type 2) is clinically significant for ACLS because this rhythm can rapidly progress to complete heart block
Secocnd-degree AV block (Type 2) should be treated with immediate transcutaneous pacing or transvenous pacing because there is risk that electrical impulses will not be able to reach the ventricles and produce ventricular contraction.
Below is a short video which will help you quickly identify second-degree AV block type 2 on a monitor. Please allow several seconds for the video to load.
It awesome
Would you pace Second Degree Heart Block- Type 2 immediately although patient is stable and asymptomatic ? Or just standby and monitor first ? If no pacer available can IV Dopamine or Epinephrine be used instead ?
Hi CL,
If the patient is not symptomatic and is stable, you would standby and monitor. I would also seek expert consultation. I would do ACS (acute coronary syndrome) workup as 2nd degree heart block Type-2 is often associated with MI. –Kind regards, Jeff
watching these rhythms along with differiated explination is very helpful study guide. Thank you
Thank you so much for this informative web site. This really helped reinforced the various rhythms-our nsg. floors now have tele beds and this site has been great-especially for recertification review.