Wednesday, 19 September 2012

ECG of the Week - 17th September 2012 - Interpretation

I've got no information on this weeks ECG but let's see what we can make of it.

Click to enlarge

  • 78
  • Regular
  • Sinus Rhythm
  • Right Axis Deviation (+100 deg)
  • PR - Prolonged (~320ms)
  • QRS - Broad (120ms) 
  • Note as Christopher has pointed out his comment there is variability in QRS width across the leads
  • QT - 380ms (QTc Bazette ~ 420 ms)
  • ST Elevation V2-6, I, II, aVF

  • Tall p waves lead II (~4mm)
  • Prolonged p waves lead II (120ms)
  • Notched p wave V1 (measurements difficult on image & paper copy due to photocopying - positive deflection >1mm < 2mm, negative deflection ~1mm, duration of negative deflection ~80ms)
  • Some features suggestive of LVH given RBBB pattern (Prominent R waves lateral precordial leads, R wave V5 ~29mm)
  • 1st Degree AV Block
  • RBBB - using longest QRS duration (Partial RBBB using shortest) 
  • Note RAD possible bifasicular block - LPFB + RBBB 
  • Other causes for RAD also likely e.g pulmonary disease
  • Right Atrial Enlargement
  • Features of Left Atrial Enlargement - ? Biatrial Enlargement
  • Concave ST Elevation - ? Acute ? Chronic ? Dynamic 
  • ? LV Diastolic Overload - Positive T wave and ST elevation in high voltage left Precordial Leads

I'm not sure about this one, there are lots of interesting features. 
I've gone back to my papercopy of the ECG to try and source some clinical information but have come up empty handed. This is an ECG that I think really needs some correlation with the clinical picture, and ideally old ECGs. The differentials for this ECG pattern are broad and include chronic pulmonary disease, valvular disease (single or mixed), the ST changes could be acute or chronic. 
I'd like to thank people for their comments on this one and would like to encourage any further comments as I think this is one of the most interesting ECGs we've had a look at on the blog. 

References / Further Reading

Life in the Fast Lane


  • Hancock EW et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy. Circulation. 2009 Mar 17;119(10):e251-61. Full text here.
  • Surawicz B, Knilans TK. Chou's Electrocardiography in Clinical Practice. 6th Edition. Saunders Elsevier 2008.
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.

1 comment:

  1. Of note, while there is certainly some degree of widespread ST-elevation, its true amplitude may be a bit less impressive than it first appears.

    Usually the Ta-wave (T-wave following the p-wave) plays a role in the location of the J-point because it deflects in the opposite direction of the P-wave with an average duration of 440ms from the start of the P-wave to the end of the Pa-wave. As a result, it's usually oriented downward and extends through the QRS into the ST-segment, dropping the J-point by varying degrees.

    Well here the PR-interval is just about 320ms with a QRS-interval around 120ms, totalling the magic value of 440ms. We get all of the PR-depression effects ahead of the QRS, but minimal, if any of the associated ST-depression to "level the playing field" after. The short duration of the TP-segments works to further the effect by lending a large percentage of the baseline to the PR-segment when you try to eyeball it.

    Taking that into account, there's still some impressive ST-elevation in many leads, but it's something to keep in mind.

    I'm left wondering if the obvious atrial hypertrophy we see can have effects on the Ta-wave paralleling what with see with LVH and "strain." Probably?