ecgs: ischemia and infarction afams resident orientation 26 march 2012
TRANSCRIPT
ECGs: Ischemia and Infarction
AFAMS Resident Orientation26 March 2012
Outline
Terminology
• Injury– Acute MI– ST elevation in 2 contiguous leads– Reciprocal ST depression
• Ischemia– ST depression, T wave inversion
• Infarct– Q waves
EKG Stages of MI
• Hyperacute T waves (A)• ST elevation (B)• Q waves – usually
within 6-12h (C) • T wave inversions (D)• ST-T wave resolution– Q waves persist
European Heart Journal 2007; 28, 2985-2991
EKG Stages of MI
• Hyperacute T waves
Sinus tachycardia, Inferior MI – recent, Nonspecific ST-T wave changes
NSR, Biatrial Enlargement, Old inferior MI
Localization of MI
• Anteroseptal– ST elevation in V1-V3
• Anterior– ST elevation in V2-V4
• Lateral– ST elevation in I, AVL, V5-6
• Inferior– ST elevation in II,III,AVF
47 year old male with chest pain
NSR with anteroseptal myocardial infarction
65 year old male with chest tightness
NSR with acute anterior myocardial infarction
62 year old female with shortness of breath and chest discomfort
Sinus Tachycardia with Lateral Myocardial Infarction
45yo wm with 2 hours of SSCP that started during exertion
NSR with PVC, LAD, Acute anterolateral MI
Middle age white male awoke from sleep with chest pain
Sinus tachycardia, Acute Inferior MI
Right Sided ECG
• Who?– Any patient with inferior
ST elevation MI
• Why?– Investigate infarct
involvement of RV
• How?– Reverse Precordial Leads
• Where to Look?– ST elevation in V4R
Right Sided EKG
Not all ST changes are ischemia
• While ischemia and infarction are the most concerning causes of ST changes, other causes exist
• Use the clinical history to help you• Recognize patterns
20 year old asymptomatic male
Sinus bradycardia, Early repolarization -> Normal variant
NSR, PACs, LVH – voltage criteria, repolarization abnormality HCM
59yo female presents to the ER with CP
NSR, Acute pericarditis (Diffuse ST elevation and PR depression), and Pericardial effusion (electrical alternans)
26 year old male with syncope
NSR, RBBB, Long QT-> Brugada Syndrome
Differential Diagnosis of ST elevation
• STEMI• LV aneurysm• Left Ventricular
Hypertrophy• Pericarditis / Myocarditis• Early Repolarization
– Normal variant
• Hyperkalemia• Brugada Syndrome• ARVD
Examples of ST Elevations
NEJM 2003: 349:2128-35
Conclusions
• ST changes often represent ischemia, injury or infarction
• Many other possible diagnoses• Use clinical information to narrow down the
list• When you are unsure, call a cardiologist