the long way round…

the case.

a 52 year old male presents to your Emergency Department with more than 24 hours of typical sounding, retrosternal chest pain.

He has a prior history of ischaemic heart disease & an LAD stent placed 3 years earlier.

On examination:
Pale & clammy.
P 136/min, BP 104/60 mmHg, SaO2 92% (RA).
RR 30 with slight bilateral crackles.

This is his ECG…

[DDET Describe & interpret his ECG…]

•  Rate:
  • 138 bpm.
• Rhythm.
  • Sinus.
• Axis.
  • Normal [+40*].
• Intervals.
  • PR ~ 160msec.
  • QRS ~ 80msec.
  • QTc ~ 380msec.
• Segments.
  • Widespread ST elevation;
    • “Tombstone” STE V1-4 [max ~5mm] w/ associated Q-waves.
    • Concave-up STE V5-6 + lead I
    • Concave-up STE [1-2mm] in inferior leads [II, III + aVF].
  • ST-depression in aVR ~1.5mm.
  • PR segments.
    • Depressed in III + aVF
    • ?subtle elevation in aVR

Interpretation.

Widespread ST-segment elevation consistent with acute anterior “tombstone” ST-elevation myocardial infarction meeting reperfusion criteria.

• Prior Hx of LAD stent + presence of anterior Q-waves ?stent thrombosis
• Inferior ST-segment elevation.
  • ?wrap around LAD
  • ???associated pericarditis.

The presence of tachycardia, basal crackles and borderline hypotension is concerning for early cardiogenic shock.

This patient warrants early Cardiology involvement and prompt transfer for PCI.

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[DDET The angiogram…]

Left ventriculogram:

• Ejection fraction ~ 49%
• Regional wall motion abnormalities:
  • Anterolateral akinesis
  • Apical akinesis
  • Inferior hypokinesis

Angiogram:

Left coronary…

100% mid-LAD occlusion → successfully stented [see below]

Right coronary…

Despite the inferior changes, the RCA was pristine.

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[DDET Post-balloon…]

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[DDET The diagnosis…]

Wrap around LAD.

ECG. 

• Simultaneous ST-segment elevation in the precordial and inferior leads.

In the presence of anterior STEMI, the amount of ST depression in the inferior leads is typically predictive of a more proximal LAD lesion. Even in the presence of a wrap-around LAD (ie. with inferior wall transmural ischaemia), almost all LAD occlusion proximal to D1 is show inferior ST depression.

A more distally occluded LAD is thought to be a prerequisite for isoelectric inferior ST-segments.

Additional ECG findings suggestive of a wrap-around LAD include ST-depression in lead III (with a positive T-wave) associated with ST-elevation in aVL.

Anatomically.

• Occurs due to an occlusion of a variant “type III” LAD.
• This wraps around the cardiac apex, supplying both the anterior and [partial] inferior walls of the left ventricle.

In our patients’ case;

For more examples of wrap around LAD lesions check out the following from Dr Smith’s ECG Blog;

1. 24 yo woman with chest pain: Is this STEMI? Pericarditis?
2. Pericarditis, or Anterior STEMI? The QRS proves it.Hyperacute T-waves, with a Twist
3. Hyperacute T-waves, with a Twist.

Interestingly, the combination of anterior and inferior ST-segment elevation appears to be associated with limited AMI size and better preserved LV function (when compared to anterior STEMIs with either isoelectric or depressed inferior ST segments).

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[DDET References.]

1. Sadanandan, S., et al. (2003). Clinical and angiographic characteristics of patients with combined anterior and inferior ST-segment elevation on the initial electrocardiogram during acute myocardial infarction. American Heart Journal, 146(4), 653–661.
2. Engelen, D. J., et al. (1999). Value of the electrocardiogram in localizing the occlusion site in the left anterior descending coronary artery in acute anterior myocardial infarction. Journal of the American College of Cardiology, 34(2), 389–395.
3. Porter A, Sclarovsky S, Ben-Gal T, et al. Value of T-wave direction with lead III ST-segment depression in acute anterior myocardial infarction: electrocardiographic prediction of a wrapped left anterior descending artery. Clin Cardiol 1998;21:562–6.
4. Gibson, CM., et al. (1996). TIMI frame count: a quantitative method of assessing coronary artery flow. Circulation. 1996 Mar 1;93(5):879-88.
5. Anterior myocardial infarction – Life in the Fast Lane.
6. Dr Smith’s ECG Blog

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