ECG of the Week: ECG of the Week - 3rd April 2017

The following ECG is from a 48 yr old male who attended the Emergency Department following an electric shock. The electricity source was a 240V AC domestic supply and the patient sustained a minor burn to his hand.

Click to enlarge

Rate:

54 bpm

Rhythm:

Regular
Sinus Rhythm

Axis:

Normal

Intervals:

PR - Normal (~120ms)
QRS - Normal
QT - 420ms

Segments:

ST Elevation leads aVR, V1-2
ST Depression leads II, aVF, V4-6

Additional:

Deep T wave inversion leads V2-6

Terminal positive deflection to T wave in these leads ?U wave

T wave inversion leads I, II, aVF
Massive R waves in all precordial leads

Interpretation:

Extensive T wave abnormalities with massive precordial complexes

The differential for these ECG features given the clinical scenario would be:

Electrical injury related
Incidental finding of cardiomyopathy ( ECG pattern favours apical variant)

What happened ?

On history review the patient had no history of loss of consciousness, syncope, palpitations or chest pain related to his presenting injury. There was a positive family history of cardiomyopathy in a close relative but no history of sudden cardiac death.
The patient was admitted under cardiology for further investigation.
The patient had negative serial troponins and underwent angiogram which showed:

Normal coronary arteries
Normal LV function
? Apical hypertrophy

Subsequent echo showed:

Normal LV cavity size and function
Asymmetric distribution of left ventricular hypertrophy affecting the apical LV region

The patient's investigation findings are consistent with apical hypertrophic cardiomyopathy, sometimes referred to as Yamaguchi Syndrome. He was discharged with ongoing cardiology follow-up.

You can read more about apical hypertrophic cardiomyopathy in the links below:

What about the electrocution ?

There are a wide variety of ECG features that have been reported in the setting of electrocution including:

Arrhythmia - AF, VT, VF
AV Block - all types
ST / T wave changes
QRS Abnormality

The following study reviewed the role of cardiac monitoring after an electrical injury and suggests that those patients who are asymptomatic with no loss of consciousness following a low voltage (<1000v a="" cardiac="" do="" ecg="" font="" monitoring.="" normal="" not="" ongoing="" require="" shock="" with="">