Sometimes a picture is worth MORE than a 1000 words. Such is the case of the above illustration that I saw on the Life In The Fast Lane blog. When I first saw it, I knew that I immediately had to find out who made the graphic. It turns out it is the multitalented Dr. Tor Ercleve, who is an emergency physician at Sir Charles Gairdner Hospital and an established medical illustrator.

This graphic demonstrates the EKG findings for the various types of acute MI’s as broken down by coronary vascular anatomy (right coronary artery, left circumflex artery, left anterior descending artery). This detailed illustration won’t be readable in print form but is great in digital format on your mobile device.

Thanks, Tor!

[PDF]

It is difficult to determine if a patient with a left bundle branch block (LBBB) has an acute myocardial infarction (AMI) because ST segments are “appropriately discordant” with the terminal portion of the QRS. That means if the QRS complex is negative (or downgoing), the ST segment normally will be positive (or elevated). Similarly if the QRS complex is positive (or upgoing), the ST segment will be negative (or depressed).

PV Card: Sgarbossa’s Criteria

In 1996, Sgarbossa et al looked through the GUSTO-1 trial patients with LBBB and AMI. They derived 3 criteria which may help diagnose the “hidden” AMI. The criteria are:

1. ST elevation ≥ 1 mm concordant with QRS complex (most predictive of AMI of the 3 criteria)
2. ST depression ≥ 1 mm in lead V1, V2, or V3
3. ST elevation ≥ 5 mm where discordant with QRS complex

Use these criteria with caution though. None of these criteria are perfect. They are to help you risk-stratify. For instance, criteria #3 (ST elevation ≥ 5 mm) can exist in asymptomatic patients with LBBB because of concurrent left ventricular hypertrophy and high voltages.