Practice EKG Rhythm Strips 170

Identify the following rhythms.

1.

2.

3.

4.

5.

Answers

1.

3rd degree heart block

The rhythm is irregular.   The atrial rate is 68/min and the ventricular rate is around 35/min.  The P waves are upright but are not associated with the QRS complexes.  The 1st QRS complex is much narrower than the 2nd and 3rd.   This may be represent some kind of junctional escape mechanism.  PR:  ---,  QRS:  .14 sec,  QT:  52 sec.

2.

Normal sinus rhythm 

The rhythm is regular with a rate of 60/min.  The P waves have a biphasic morphology.  No ectopic beats are noted. There is 6mm ST elevation in lead II and ST depression and large Q waves in V1.  PR:  .16 sec,  QRS:  .12 sec,  QT:  .40 sec.

3.

NSR with a PAC

The rhythm is irregular due to a PAC.   The rate is 70/min.  The P waves are upright and precede the QRS complexes.  The 5th QRS complex occurs early in the cardiac cycle and has a P wave morphology that is different from the other P waves.  PR:  .16 sec,  QRS:  .08 sec,  QT:  .42 sec.

4.

Sinus arrhythmia with a junctional escape beat

The rhythm is irregular.  The R-R interval between the 1st and 2nd complexes is 1.12 sec and the R-R interval between the 2nd and 3rd complexes is .96 sec. The rate is 50/min.  The P waves are present and upright on all the complexes except the 4th complex.  There is a 1 second pause between the 3rd and 4th complex.  The 4th complex appears late in the cardiac cycle and represents a junctional escape mechanism.  This is followed by another pause before a sinus beat is initiated.

5.

Sinus bradycardia

The rhythm is regular with a rate of 48/min.  The P waves are upright, uniform, and precede the QRS complexes.  No ectopic beats are present.  There is mild up slopping of the ST segment.  PR: .16 sec,  QRS:  .12 sec,  QT:  .44 sec.