Wednesday, 19 December 2012

ECG of the Week - 17th December 2012 - Interpretation

This ECG is from 46 yr old man presenting with several months of exertional dysponea and fatigue. At the time of review his BP was 110/60 mmHg.
Thoughts ? Differential diagnosis ?






Click to enlarge
Rate:
  • Atrial Rate 83 bpm
  • Ventricular rate 42 bpm
Rhythm:
  • Regular
  • No relationship between P waves : QRS complexes
Axis:
  • Normal (~65 deg)
Intervals:
  • PR - No relationship
  • QRS - Normal (80ms)
  • QT - 440ms (QTc Bazette ~ 390 ms)
Segments:
  • Apparent ST elevation in V3 although likely to be secondary to p wave superimposition
Interpretation:
  • Complete heart block with junctional escape rhythm.
Differential Diagnosis
  • Ischaemia
  • Medications
      • Cardiotoxic agents
        • Therapeutic
        • Delibrate Self Harm
  • Electrolye / Acid-base disturbance
  • Aortic Valve Disease
  • Congenital Cardiac Disease - Valvular or EP disturbance
  • Sarcoidosis
  • Myocarditis
  • Thyroid Dysfunction - Hyper- or hypo-
What happened to this patient ?
  • Stress Echo - Nil evidence ischaemia with normal LVEF
  • Cardiac MRI - Nil evidence sarcoidosis
  • PET Scan - Nil evidence sarcoidosis
  • Nil reversible / correctable cause found for CHB
  • Dual chamber PPM Implanted (MRI Compatible)
Thanks to both Christopher and Vince DiGuilio for their comments on this ECG.

Don't forget to check out Christopher's works over at http://sixlettervariable.blogspot.com.au/ and if his Blogger profile is right, over here as well Paramedicine101. 

Check out Vince's Google+ ECG+ Community for more excellent ECG discussions, and check out his website The Medical Appraoch to EM. You can also follow Vince on twitter @MedicalApproach

Thanks to Dr Shakeeb Razak for sharing this interesting case.

References / Further Reading
 

Life in the Fast Lane

  • Complete heart block here
Articles
  • Kandolin R, Lehtonen J, Kupari M. Cardiac sarcoidosis and giant cell myocarditis as causes of atrioventricular block in young and middle-aged adults. Circ Arrhythm Electrophysiol. 2011 Jun;4(3):303-9. PMID: 21427276 Full text here
Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.