ECG of the Week – 25th January 2015 – Interpretation

This week's ECG is another ECG from our patient from last week and the week prior to that. He is an 88yr old male who had an episode of VT on a background of ischaemic cardiomyopathy. Following successful cardioversion he underwent an ICD insertion. He then presented to the Emergency Department complaining of palpitations.




Click to enlarge


Rate:
  • 168
Rhythm:
  • Regular
Axis:
  • LAD
Intervals:
  • QRS - Prolonged (140ms)
Segments:

  • Concordant ST depression in leads V3-6
  • Limb leads show expected discordance

Additional:

  • Regular atrial activity best seen in leads V3-5 in 1:1 ratio with QRS without AV dissociation
  • No precordial concordance
  • RBBB Morphology Rsr' in lead V2
  • Absence of pacing spikes

Interpretation - Broad differentials include:

  • SVT with aberrancy / pre-existing conduction abnormality
    • Clearly different morphology from prior VT seen here
    • Lack of AV dissociation / Concordance
  • VT
    • Prior episode of VT and known cardiomyopathy
    • Not favored due to lack of ICD shock delivery and morphology features noted above - possibility of ICD malfunction should be considered
  • Pacemaker mediated tachycardia
    • Nil evidence of pacing spikes
    • Morphology clearly different when compared with prior v-paced ECG here


What happened ?

The treating clinicians were concerned about the possibility of ICD malfunction and treated the ECG as VT and performed a successful DC cardioversion.

So why didn't the ICD shock the patient ? There are only two simple possibilities:

  • Something is wrong with ICD
  • It's not VT

In this case the ICD didn't fire because this wasn't VT. On pacemaker interrogation this was an episode of atrial tachycardia with aberrant conduction and a further episode whilst an in-patient was terminated with iv sotalol.

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 – 25th January 2015

This week's ECG is another ECG from our patient from last week and the week prior to that. He is an 88yr old male who had an episode of VT on a background of ischaemic cardiomyopathy. Following successful cardioversion he underwent an ICD insertion. He then presented to the Emergency Department complaining of palpitations.




Click to enlarge


Things to think about

  • What are the key ECG features ?
  • What are the differentials for these findings ?

ECG of the Week – 18th January 2015 – Interpretation

This week's ECG is another ECG from our patient from last week. He is an 88yr old male who had an episode of VT on a background of ischaemic cardiomyopathy. Following successful cardioversion he underwent an ICD insertion. His CXR and ECG are shown below.



Click to enlarge
Rate:
  • 60
Rhythm:
  • Regular
  • Retrograde P waves visible in mid-portion of ST segment
    • Inverted P leads II, III, aVF
Axis:
  • RAD
Intervals:
  • QRS - Prolonged (130ms)
  • QT - 420ms
Segments:

  • Discordant ST segment changes

Additional:

  • Prominent T waves especially leads V2-4 in comparison to QRS magnitude
  • Notching in S wave leads V1-2

Interpretation:

  • V-Paced Rhythm
  • Retrograde P waves
  • Prominent T waves should raise possibility of hyperkalaemia or acute ischaemia but in this case represent patient's 'normal' paced ECG - likely secondary to associated scarring from ischaemic cardiomyopathy


Click to enlarge

What about the CXR ?

I don't normally cover x-rays on this blog but this one has a few interesting points relating to implantable devices. There is a disconnected old RV pacing lead which ends in overlying the right hemithorax- labelled in green below. There is a new left ICD over the left mid chest with the lead also implanted in the right ventricle. The distal portion of the new lead is the shock coil. This ICD also has an atrial sensing function, the sensors are the two dense square blocks situated in the right atrium.

Click to enlarge

This patient has a Biotronik Lumax ICD which has the ability to provide atrial sensing via a single lead. This allows differentiation between SVT, AF and VT without having to implant an atrial lead. The advantage of a single lead insertion is that it is a quicker procedure and is associated with less complications.

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 – 18th January 2015

This week's ECG is another ECG from our patient from last week. He is an 88yr old male who had an episode of VT on a background of ischaemic cardiomyopathy. Following successful cardioversion he underwent an ICD insertion. His CXR and ECG are shown below.




Click to enlarge

Click to enlarge

Things to think about
  • What are the key ECG findings ?
  • What are the key CXR findings ?

ECG of the Week – 11th January 2015 – Interpretation

The following ECG is from an 88 yr old male with a known history of ischaemic cardiomyopathy. He presented complaining of palpitations and dizziness for the preceding hour.


Click to enlarge

Rate:

  • 196 bpm
Rhythm:
  • Regular
Axis:

  • Right Axis Deviation
Intervals:
  • QRS - Prolonged (140ms)
Segments:


  • Discordant ST segment change
Additional:

  • Positive precordial concordance
  • Absence of typical BBB pattern

Interpretation:

  • Ventricular Tachycardia
    • Patient features
      • Elderly
      • Known ischaemic cardiomyopathy
  • ECG Features
    • Broad complex tachycardia
    • Absent typical BBB morphology
    • Precordial concordance


What happened ?

The patient underwent successful DC cardioversion and was admitted under cardiology team. Find out what happened to this patient over the next 2 weeks.

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.