Monday, 8 February 2010

72 yom CC: Unknown Problem (Man Down)

EMS is dispatched to a 72 year old male patient. Third party call. History of Parkinson's Disease. Patient is conscious. No further information.

On arrival, EMS finds a 72 year old Spanish-speaking male. Through an interpreter the lead paramedic determines that the patient became dizzy, fell down, and hit his head. A small hematoma is visible above the patient's right eye.

The patient is awake but somnolent. He is oriented to person, place, time, and event. The remainder of the neurological exam was normal.

Since the patient is not alert the crew applies manual C-spine stabilization and continues the exam.

The patient denies chest pain or shortness of breath.

Breath sounds are clear bilaterally.

The patient denies any significant medical history and states that he takes no medications.

Vital signs are assessed.

Resp: 18
Pulse: 80
BP: 104/70
SpO2: 98 on RA

The cardiac monitor is attached.


A 12-lead ECG is captured.

The lead paramedic notes that the arm leads are reversed. The problem is corrected and another 12-lead ECG is captured.

The black electrode is replaced and a third 12-lead ECG is captured.

What is your impression and what would you do next?

*** Update 02/09/2010 ***

In the first graphic you can see that it's debatable as to whether or not 1 mm of ST-segment elevation is actually present in the 12-lead ECG when you use the TP segment as the baseline.

The first complex in lead III helps foster the perception, probably due to wandering baseline.

Compounding the illusion is the ST-depression in lead aVL! This is one of the first things I look for when considering the ECG diagnosis of acute inferior STEMI.

It's helped me pick up on dozens of subtle presentations!


In the second graphic I've blown up lead II so you can clearly see the PR-segment depression.

This is important for two reasons. First, it fools your eye into the thinking that ST-segment elevation is present. Secondly, it fools the GE-Marquette 12SL interpretive algorithm!

Having said that, I have respect for the GE-Marquette 12SL interpretive algorithm, and I'm certain it also picked up on the ST-depression in lead aVL.

Keep in mind that the ACC/AHA STEMI criteria is far from perfect. I've called STEMIs before with less than 1 mm of ST-segment elevation, specifically when ST-depression was present in lead aVL.

Do you remember this 12-lead ECG from a previous post?

The patient ended up having a 100% occlusion of the RCA!

I've had some really great comments on this case so far. Is your perception of this ECG changing?

Does this case demonstrate that sometimes, the emergency department is exactly where a suspected acute STEMI patient (with a marginal ECG) belongs until the diagnosis can be confirmed through other means?

I'll be posting the conclusion to the case in the next couple of days.