ECG of the Week – 19th September 2016 – Interpretation

This ECG is from an 88 yr old male with a history of ischaemic heart disease and PVD. I don't know what his presenting complaint to the Emergency Department was, but what does his ECG show ?




Click to enlarge
Rate:
  • Ventricular rate 48 bpm
  • Atrial rate 72 bpm
Rhythm:
  • Regular atrial activity
  • Group ventricular activity
  • Wenckebach pattern
    • Progressive PR prolongation
    • Dropped QRS
    • P:QRS 3:2 ratio
Rhythm Strip with P waves labelled
Click to enlarge
Axis:
  • LAD
Intervals:
  • PR
    • Progressive PR prolongation
    • Initial PR ~160ms
    • Then PR ~340-360ms
    • Then P wave with dropped QRS
  • QRS - Prolonged (160ms)
Segments:
  • Sgarbossa negative
  • Discordant ST segment change
Additional:
  • Typical LBBB morphology
Interpretation:

  • LBBB - longstanding
  • Type I 2nd Degree AV Block / Wenckebach


We've had several cases of Wenckebach features on the blog, links below:


Most sources will sight Wenckebach as a benign AV block with a low chance of progression to complete heart block but intervention may still be indicated. 

The following is taken from the ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities (full text here).

Type I second-degree AV block is usually due to delay in the AV node irrespective of QRS width. Because progression to advanced AV block in this situation is uncommon, pacing is usually not indicated unless the patient is symptomatic. Although controversy exists, pacemaker implantation is supported for this finding..... However, it is not always possible to determine the site of AV block without electrophysiological evaluation, because type I second-degree AV block can be infranodal even when the QRS is narrow. If type I second-degree AV block with a narrow or wide QRS is found to be intra- or infra-Hisian at electrophysiological study, pacing should be considered.

What happened ?

The patient presented to the Emergency Department with progressive cardiac failure in the setting of NSTEMI. During inpatient telemetry he was found to alternate between atrial fibrillation, 2nd degree AV block and complete heart block, he underwent an uneventful pacemaker insertion.

References / Further Reading

Life in the Fast Lane

Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.

ECG of the Week – 12th September 2016 – Interpretation

The following ECG is from a 43 yr old male who was referred from his GP due to concerns over an abnormal ECG. He presented with several months of exertional dysponea, chest pain and dizziness. He was asymptomatic at GP and Emergency Department presentation.



Click to enlarge


Rate:
  • 84 bpm
Rhythm:
  • Regular
  • Sinus Rhythm
Axis:
  • Normal
Intervals:
  • PR - Normal (~200ms)
  • QRS - Normal (110ms)
  • QT - 400ms (QTc Bazette 435 ms)
Segments:

  • ST depression leads I, II, V4-6

Additional:

  • Deep T wave inversion leads I, II, aVL, aVF, V3-6
  • QRS voltages in infero-lateral leads appear high without meeting LVH criteria

Interpretation:

  • Clinical history and ECG features most concerning for cardiomyopathy
  • ECG features most likely suggest apical hypertrophic cardiomyopathy (aka Yamaguchi syndrome) given the deep T wave inversion in the lateral and inferior leads.


What happened ?

He was admitted under cardiology for investigation.
Angiogram showed only 30% stenosis of the proximal circumflex complicated by contrast allergy.
ECHO showed:

  • Normal LV size with akinesis of the paical cap.
  • Asymmetrical hypertrophy of LV basal walls and apex
  • Small apical aneurysm
  • Preserved systolic function
  • Increased LV wall thickness and prominent apical thickening
  • Normal RV size and systolic function

Features on echo consistent with apical hypertrophic cardiomyopathy. The patient is awaiting an out-patient cardiac MRI given potential DDx of sarcoid.

References / Further Reading

Life in the Fast Lane

Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.

ECG of the Week – 12th September 2016

The following ECG is from a 43 yr old male who was referred from his GP due to concerns over an abnormal ECG. He presented with several months of exertional dysponea, chest pain and dizziness. He was asymptomatic at GP and Emergency Department presentation.




Click to enlarge

Things to think about

  • What are the key ECG findings ?
  • What are the differentials for these features ?
  • How would investigate this patient ?