Lecture 6- ST and Hypertrophy Flashcards
Where QRS complex and ST segment meet?
J point
One of the most important aspects of an ECG?
ST segment
Describe normal ST segment
ST segment should be at baseline
ST segment is smooth and blends into T wave
Describe abnormal ST segment changes in regards to baseline
Changes of > 2 mm in 2 or more leads = abnormal
(Changes of < 1 mm is normal in limb leads)
*imp to listen to pt
Pathologic ST seg changes?
ST depression = ischemia or NSTEMI
ST elevation = injury/infarct (STEMI)
Benign ST seg changes?
Pericarditis (↑)
Early Repolarization (↑)
Ventricular Hypertrophy with strain (↑ or ↓)
Bundle Branch Blocks (↑ or ↓)
benign or pathologic? ST segment elevation with downward concavity
pathologic (sad face, downward curve)
benign or pathologic? ST segment elevation with upward concavity , especially with notching of J point
benign (happy face, upward curve)
Normal T wave should be symmetrical or asymmetrical?
asymmetrical
Symmetrical T waves (usually pathologic) can be an indication of:
Ischemia/infarct
Hyperkalemia (tall and narrow)
Intracranial hemorrhage (broad and wide)
T wave size is abnormal if:
> 2/3 height of R wave
Tall T waves can indicate
Ischemia/Infarct
CNS events
Hyperkalemia
T waves can be positive, negative, biphasic, or flat. Which leads are they usually positive in? Negative?
Lead I, II, V3-V6;
negative in aVR
Biphasic t waves- what is the significance of the first part of the wave being either negative or positive?
If first part of T wave positive, more likely to be benign
If first part of T wave negative, more likely to be a sign of pathology
Ischemia or NSTEMI features:
Flat or downsloping ST segment
Symmetrical inverted or biphasic T waves
STEMI features
Flat or downward concave
-ST segment- “frowny face”/“tombstoning”
Symmetrical T waves (↑ or↓)
Diffuse ST segment elevation- upwardly concave
PR segment depression
Notching at the end of QRS complex
….characteristic of what?
Pericarditis (benign ST elevation)
- will be this in most leads
- chest pain laying down, with inspirations, cardiac rubs
- common in young, black males
Describe early repolarization
Similar pattern to pericarditis except no significant PR segment depression
Benign ST segment elevation- upwardly concave
Notching at end of QRS complex
Generally found in younger people
Right Atrial Enlargement?
P wave in lead II:
> 2.5 mm high
Peaked shape = “P pulmonale”
P wave in lead V1:
If biphasic, positive half taller and wider than negative half
Left Atrial Enlargement?
P wave in Lead II:
> 0.12 seconds long
M shaped = “P mitrale”
Camel humps- at least one small box between
P wave in Lead V1:
Biphasic with second half at least 1 small box wide and deep
Biatrial Enlargement?
A combination of criteria for RAE + LAE
Left Ventricular Hypertropy?
Deepest S wave in V1 or V2 + Tallest R wave in V5 or V6 ≥ 35 mm
(high amplitude in precordial leads, also would need an echo)
When can LVH criteria not be used?
in the presence of LBBB, WPW, ventricular rhythms, and certain electrolyte and drug effects that alter the QRS complex
What if R waves from different leads are overlapping on your tracing?
Repeat tracing at half-standard calibration (check box on right hand side)
