A Guideline from the Steve Smith’s ECG Blog and the EMCrit Podcast

Today, I am joined by Steve Smith, creator of one of the best ECG blogs out there. We discuss who needs an emergent cath. Who should get a transfer to a PCI center? Wouldn't it be great if all of the possibilities were gathered in one place? Here you go...

The Printable Versions:

* The Complete Document

* The Cheat Sheet

The Video Version from theEMC

Who needs an emergency PCI?

Activate the Lab for unambiguous STEMI (only clear STEMIs have a 90 minute CMS mandate). Get Cardiology or Interventional Consultation for more complicated cases: difficult ECGs, subtle ST elevation, ST depression with ongoing symptoms, STEMI “Equivalents”. This requires a systematic approach, with buy-in from Cardiology that they will respond immediately to such requests for help. What do they get out of it? Fewer false positive activations and more activations for the subtle cases that need it.

Know that the ACC/AHA guidelines for NonSTEMI recommend < 2 hour cath for:

* Refractory ischemia

* Ischemia with hemodynamic or electrical instability

Proviso: Many non-interventional cardiologists do not understand these subtle ECG findings or pseudo-STEMI patterns. You must be a strong advocate! If you are worried, get serial ECGs, compare with an old ECG, and get a high quality contrast echocardiogram exam. Persistent occlusion of a significant epicardial coronary artery will nearly always have a wall motion abnormality if the echo quality is good, is done with contrast, and is read by an expert.

I. ACC/AHA Criteria

ST-elevation at the J point in 2 contiguous leads that reaches the following thresholds: [cite source='doi']10.1161/CIR.0b013e3182742c84[/cite]

* Men < 40 years of age: 2.5 mm in V2-V3 and 1 mm in all other leads

* Men > 40 years of age: 2 mm in V2-V3 and 1 mm in all other leads

* Women: 1.5 mm in V2-V3 and 1 mm in all other leads

These criteria are only 45% sensitive for MI as measured by CK-MB, and about 70% sensitive for acute coronary occlusion, with perhaps 85% specificity. Beware of early repolarization, LVH, and LV aneurysm as false positives. Beware of subtle ST elevation as false negatives. Other less specific but more sensitive criteria require “new” ST elevation.

II. New Left Bundle Branch Block

New LBBB alone is not an indication for cath lab activation. MI may also present in the context of old LBBB. Therefore, in stable patients, determine if there is a concordant ST segment, or an excessively discordant ST segment (see figure) and then use the algorithm below:

Activate if any of these three: [cite source='pubmed']24016487[/cite]

* In an unstable patient (hypotensive, Acute Pulmonary Edema, electrical instability, or looks sick) [cite source='pubmed']22766335[/cite]

* Sgarbossa Criteria (1 of the following) [cite source='pubmed']8559200[/cite] & [cite source='pubmed']22939607[/cite]

* Concordant ST-segment elevation of 1 mm in at least 1 lead

* Concordant ST-segment depression of at least 1 mm in leads V1 to V3

* Note: I reduce these two to simply: Concordant ST-Segment Deviation

* They have Smith-Modified Sgarbossa criteria [cite source='pubmed']22939607[/cite] Any single lead with at least 1 mm of discordant ST elevat...