EKG Rhythm Strips 24: Ectopic beats

Identify the following rhythms:

1.

2.

3.

4.

5.

6.

Answers
1.

Sinus arrhythmia with a PVC and some PACs

Sinus arrhythmia with a PVC and some PACs (bigeminy pattern)  The PACs are the 7th and 9th complexes.
The complexes are early (shorter R-R interval) and are narrow, < .12 sec.  There is an upright P wave before each complex and the morphology of the P waves is different from the previous P waves.

2.

Sinus rhythm with a PJC and some PACs (bigminy pattern)

Sinus rhythm with a PJC and some PACs (bigminy pattern).   The PJC is the 2nd complex.   Notice the inverted P wave that occurs before the QRS complex.  Recall that with junctional ectopy the P wave will be inverted or absent or occur before or after the QRS complex.  This is followed by a sinus beat (3rd complex) and PACs every other beat.  (4th, 6th, 8th complexes)

3.

NSR with a PVC and a junctional escape beat

NSR with a PVC and a junctional escape beat.   The PVC is the 4th complex.  It is followed by a junctional escape beat (5th complex).  After the long pause that follows the PVC if the primary pacemaker of the heart fails to provide a pacing stimulus then secondary pacemakers will provide a pacing stimulus.  In this case the the AV junction provided the pacing stimulus and accounts for the escape beat of the 4th complex.  If you look closely at the escape beat you see a small inverted P wave before the QRS complex.

4.

NSR with 1st degree block and ventricular bigeminy

NSR with 1st degree block and ventricular bigeminy.   The rhythm is irregular.   The PR interval on the sinus beats is .22.   Each sinus beat is followed by PVCs.   The PVCs are wide, greater than .12 sec and there are no P wave present.

5.

NSR with a  PJC, PAC, and PVC

NSR with a  PJC, PAC, and PVC.    The PJC is the 2nd complex.  There is an inverted P wave before the QRS complex.  The PAC is the 4th complex.  The morphology of the P wave is very different from the sinus P waves.   The PVC is 6th complex.  The PVC has a wide and bizzare appearance.

6.

NSR with PAC and PVC.   The PAC is the 3rd complex and the PVC is the 7th complex.  The PAC occurs early in the cardiac cycle.  It has an upright P wave which distinguishes it from a PJC.  The morphology or shape of the P wave is somewhat different from the sinus P waves.   Sometimes the PR interval may also be different from the native PR intervals, depending upon the site of ectopy.  The PVC is wide.  Recall that ventricular beats are always wide, > .12 seconds and there are no P waves associated with PVCs.


Reviewed 3/1/16