63 year old male CC: Shortness of breath – Conclusion

This is the conclusion to 63 year old male CC: Shortness of breath. You may wish to go back and read the original post.

Let's take another look at the 12-lead ECG.

Now with the computerized interpretation.

This ECG shows severe left ventricular hypertrophy with a "strain pattern" or secondary ST-T wave abnormality.

A "strain pattern" often shows what I sometimes refer to as "pouty-lipped" ST-depression and T-wave inversion in the lateral leads. You can see a good example of this in leads I and aVL.

The Q-wave in lead aVL looks suspicious. However, when the patient's chart was pulled at the hospital it turned out that the patient had a history of myocardial infarction.

In addition, ST-elevation is present in the right precordial leads (V1-V3). This is normal for left ventricular hypertrophy. Typically, the deeper the S-waves the more pronounced the secondary ST-T wave abnormality in the opposite direction.

In this case the most pronounced ST-elevation is in lead V2 and you will note that the S-waves are at least 35 mm in this lead (which meets the LVH voltage criteria all by itself). With a "strain pattern" like this the ST-elevation is usually, but not always, upwardly concave.

This patient was suffering from a new onset of acute pulmonary edema and clearly has a very sick heart but ruled out for acute myocardial infarction.

According to some studies LVH is the most common cause of ST-elevation in chest pain patients so this is an ECG abnormality you should learn and keep in the back of your mind! 

Interestingly, it's not easy to find an ECG that shows acute anterior STEMI and concomitant left ventricular hypertrophy in the precordial leads. Stephen Smith, M.D. from Dr. Smith's ECG Blog has a theory that acute anterior STEMI may attenuate the voltage of the S-waves in the right precordial leads (V1-V3).

You can see a possible example of this phenomenon here: 55 year old male CC: Chest pain. I have a suspicion this ECG from the Cardiphile blog shows the same thing (ignore the fact that it says inferior wall infarction).

The take-home point is that very deep S-waves in the right precordial leads should make you question the diagnosis of acute anterior STEMI.

That's not to say that the patient may not be experiencing acute myocardial infarction! That can happen (we are contantly being told) with a perfectly normal looking ECG. Rather, I am saying that it's probably not an acute STEMI, and that's the relevant point for paramedics and physicians in the emergency department who need to make a decision about activating the cardiac cath lab.

As a final point, someone pointed out a significant change between the rhythm strip and the 12-lead ECG in lead III for this case. That's true, but keep in mind that the rhythm strip was captured in "monitor mode" where the low frequency / high pass filter was set to 1 Hz! The 12-lead ECG was captured in "diagnostic mode" with the low frequency / high pass filter set to 0.05 Hz. To get accurate ST-segments you need to be in diagnostic mode.

See also:

Left ventricular hypertrophy – Part I

Left ventricular hypertrophy – Part II

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