Answer Case 5

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The ECG

Try to interprete this ECG using the 7+2 step method

Answer

• Following the 7+2 steps:
  • Rhythm
    • The ECG shows a regular rhythm, but the last couple of beats are faster. Between these last beats clear P waves are discernable. De distance between the P waves and QRS complexes changes and there seems to be no relation between the two: AV dissociation. As there are no P waves preceding the first QRS complexes the rhythm must be of nodal origin in competition with sinusrhythm. The 10th, 12th and 13th beats are preced by a P wave, here the sinusrhythm has taken over from the nodal rhythm.
  • Heart rate
    • around 80 bpm
  • Conduction (PQ,QRS,QT)
    • PQ: not applicable. QRS: 110ms QT: 380ms
  • Heartaxis
    • Positive in I and II, negative in III. Slightly positive in AVF. An intermediate heart axis.
  • P wave morphology
    • The P waves that are present seem to have a normal morphology.
  • QRS morphology
    • Slightly broad QRS complexes. QS in V1.
  • ST morphology
    • Negative T in III oreceded by a negative QRS complex (normal).
  • Compare with the old ECG (not available, so skip this step)
  • Conclusion?

Nodal rhythm in competition with sinusrhythm.