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I am investigating the public data of this.

Its specification

201 2 360 650000
201.dat 212 200 11 1024 972 -519 0 MLII
201.dat 212 200 11 1024 982 30947 0 V1
# 68 M 1960 2851 x1
# Digoxin, Hydrochlorthiazide, Inderal, KCl
# The PVCs are uniform and late-cycle.  Junctional escape beats occur following
# episodes of ventricular trigeminy.

The data is taken from the interval $[200000, 205000]$ in the following picture with the sample rate 500 Hz.

enter image description here

There seems to be more than Premature Ventricular Contractions (PVC), extrasystoles, so possible ventricular tachycardia.

The same patient has six minutes later this

enter image description here

I think you can see clearer here those PVCs, when the ventricle is starting to contract too early.

Both are very pathological situations. How can you differentiate between the two?

Are there PVCs in both pictures?

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1 Answer 1

up vote 2 down vote accepted

I have looked at this ECG using LightWAVE.

The first part is showing atrial fibrillation or flutter with variable conduction because:

  • arrhytmia
  • no P waves or coarse fibrillatory waves
  • tachycardia at about 95-100 beats/minute
  • can be seen better in V1

enter image description here
Sample from 00:00:40

The second part is showing premature ventricular contractions with trigeminy because:

  • different morphology of QRS - ectopic
  • wide QRS
  • two normal complexes followed by one ectopic
  • presence of the compensatory pause after PVC

enter image description here
Sample from 00:09:20


  1. ECG data: PhysioNET MIT-BIH Arrhythmia Database
  2. ECG criteria: LearnTheHeart.com
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So the ventricular tachycardia is at about 95-100 beats/minute. –  Masi May 17 '14 at 15:43
@Masi you can't call it ventricular tachycardia. It appears because of the numerous stimuli generated by atrium. Only a few of these stimuli reach the ventricles because of the atrio-ventricular node. How many - that depends on the subject's age (it lowers the number of stimuli that pass through). At a younger subject atrial fibrillation may cause 150-200 beats/minute or even more. –  Cornelius May 17 '14 at 15:48
I am particularly interested in the second part. I completely agree with you about these three findings: different morphology of QRS - ectopic, wide QRS, two normal complexes followed by one ectopic and presence of compensatory pause after PVC. Those two normal QRS complexes seem to different little. Do you see any other else in the second picture? Uneven rhythm, I think. Very low rate tachycardia remnants probably 95-100 beats/second. –  Masi May 17 '14 at 15:48
@Masi yes they are sometimes different. Are you thinking of ectopic pathways? –  Cornelius May 17 '14 at 15:58
Yes, I am thinking ectopic pathways. –  Masi May 17 '14 at 17:43

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