Answer MI 14

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Where is this myocardial infarction located?

ECG MI 14. Click on image for enlargement.

ECG MI 14. Note that V3-V6 are on the right side of the chest. Click on image for enlargement.

Answer

• Describe the ECG according to the 7 + 2 stepplan
  • Rhythm
    • This is a regular rhythm and every QRS complex is preceded by a p wave. The p wave is positive in II, III and AVF and originates form the sinusnode. Conclusion: sinusrhythm.
  • Heartfrequency.
    • Use the 'Countingmethod' (6 big grids ~> 300-150-100-75-60-50), so 50/min.
  • Conductiontimes (PQ,QRS,QT)
    • PQ-interval=0.16sec (4 small grids), QRS duration=0.10sec, QT time=460ms
  • Heartaxis
    • Positive in I, iso-electric in II, negative in III and AVF. So, a left axis.
  • P wave morphology
    • The p wave is normal shaped.
  • QRS morphology
    • Conduction delay right, but not enough for the complete RBBB criteria (QRS < 0.12s). Slow R-wave progression in the precordial leads.
  • ST morphology
    • ST elevation in II,III and AVF. Reciprocal depression in I, AVR and AVL with negative T waves. Additionally discrete elevation in V2-V5. And ST-elevation in V4R
  • Compare with the old ECG (not available)
  • conclusion. What is going on?

Answer: Inferior wall infarct with right ventricular involvement and:

• Sinusbradycardia, probably because the sinusnodebranch, coming from the RCA is lacking perfusion.
• Left heart axis