5 Ischemia, Infarction, and ECG Mimics Free Online FlashCards

How do ischemia and infarction differ?

Ischemia is inadequate myocardial blood flow; infarction is myocardial injury due to ischemia. Infarction is established by integrating clinical evidence with a rise or fall in cardiac troponin.

When should the first ECG be obtained in suspected ACS?

Obtain and interpret a 12-lead ECG within 10 minutes of first medical contact. Repeat ECGs if suspicion remains, especially during persistent or recurrent symptoms.

What is the general conventional ST-elevation criterion for suspected ACS?

New J-point elevation in at least two contiguous leads supports STEMI criteria: at least 1 mm in leads other than V2–V3; V2–V3 thresholds vary by age and sex.

What can ST depression in V1–V3 indicate?

ST depression in V1–V3 may be the mirror image of posterior injury. If suspicion persists, obtain posterior leads V7–V9; elevation there supports posterior injury.

Which additional leads help assess right-ventricular infarction?

In suspected inferior infarction, obtain right-sided leads, especially V3R–V4R. ST elevation in these leads may indicate right-ventricular involvement.

What does a Wellens pattern suggest, and what should be avoided?

Deep, symmetric T-wave inversion or biphasic T waves in V2–V3 during a pain-free interval can indicate a Wellens pattern associated with critical LAD disease. Avoid exercise stress testing and seek urgent specialist assessment.

What ECG pattern may signal acute LAD occlusion without classic ST elevation?

Upsloping ST depression at the J point across precordial leads with tall, symmetric T waves can indicate acute LAD occlusion.

How should possible ischemia be assessed with LBBB?

LBBB makes ordinary ST-elevation interpretation difficult. Apply validated Sgarbossa or modified Sgarbossa criteria and consider the clinical picture; new LBBB alone is not diagnostic of MI.

What may diffuse ST depression with elevation in aVR or V1 indicate?

Diffuse ST depression with ST elevation in aVR and/or V1 can signal extensive subendocardial ischemia, including multivessel or left-main disease, especially in an unstable patient. It is not specific to one culprit artery.

Which ECG features may help distinguish acute pericarditis from a coronary-territory pattern?

Acute pericarditis often causes widespread, relatively concave ST elevation with PR depression and typically lacks a single coronary-territory pattern. Clinical features remain important.

Should clinicians wait for troponin results before urgent reperfusion when occlusion is convincing?

For a STEMI pattern or convincing occlusion pattern, activate the local reperfusion pathway and arrange immediate emergency cardiology care. Do not wait for troponin results when the ECG and clinical picture call for immediate reperfusion.

What ST-elevation thresholds apply in V2–V3?

In V2–V3, the threshold is at least 2 mm for men aged 40 or older, 2.5 mm for men younger than 40, and 1.5 mm for women.