Practice EKG Strips

Identify the following rhythm (click on the image to enlarge it).

Answers

The rhythm begins with what looks like a pause followed by a junctional escape beat, complex 1.  We know that it is junctional escape beat because the QRS complex is narrow and the P wave is absent.  Complex 2 may be an atrial escape beat.  The PR interval looks shorter than any of the other complexes.  Complexes 3 – 6 are sinus tachycardia.  There is a P wave associated with each QRS complex.  The P waves of complexes 3 – 6 are fused with the T wave of the preceding complexes.  There is a dropped PAC seen following complex 6.  The dropped P wave occurs on the T wave.  At this point the ventricle is in a state of relative repolarization and an ectopic complex may or may not be conducted.  There is a compensatory pause following complex 6.  Complex 7 is a junctional escape beat.  A nonconducted P wave follows the junctional escape beat.  It has a similar morphology to the complex 13, so I believe it is a nonconducted P wave as opposed to a PAC.  Complex 8 is another junctional escape complex or PAC.  Sinus tachycardia resumes in complexes 9 – 12.   A dropped PAC is seen fused with the T wave of complex 12.  This is followed by a compensatory pause.  Complex 13 is a junctional escape beat.  It is followed by a nonconducted PAC.  Complex 14 is another junctional escape beat.  Complexes 15 – 17 look like sinus tachycardia.  The P waves of these complexes are fused with the T waves of the preceding complexes.