My apologies for the faded ECGs. Turns out the medic (a recent grad from our hospital’s program) had been carrying them in his work pants for over a week, waiting to catch me in the ED. TheÂ patient had been brought to another hospital, but he wanted to review the ECGs with me.

They had been called for a 64 year-old woman at a gym, who had been getting ready for her Zumba class. She described an abrupt onset of precordial chest pressure, 8/10, that radiated to the jaw and left arm. Of note, the Zumba instructor insisted “We hadn’t even started the class!”

PMHx : HTN, but no CAD.

: HTN, but no CAD. Meds: ASA daily, Prevacid

Vital signs:

HR – 70

RR – 20

BP 150/84

SaO2 – 98% RA

Aside from mild sweating, the exam was unrevealing. A rhythm strip was obtained:

And then a 12-lead:

And then a second ECG, with nonstandard lead placement as noted:

At this point, the medic gave a sublingual dose of nitroglycerin.

Questions:

Clearly, this is a STEMI. What coronary artery is probably involved, and what areas of the heart are likely affected?

What do you think happens next?