ECG Interpretation Flashcards
How do you know if someone has hypertrophy? Where would you likely see this?
Left Ventricule!
Sum of S wave in V1 and R wave in V5 = >35 mm
Called Left Ventricular Hypertrophy
What is ischemia?
How does ischemia occur?
How would you be able to read it on an ECG?
Ischemia: reduced blood supply to myocardium
Occurs due to occulsion of coronary arteries
ECG: ST Depression and T wave that is flat or inverted
How do you determine if someone has just had injury done to their heart?
- Signified by ST Segment Elevation
- Only see in acute case of infarction
- Return to baseline within 24-48 hours
What is infarction and what does it look like on an ECG?
- Infarction: cell death due to occlusion of coronary arteries
- ECG: Significant Q waves (> 1 small box; 0.33 height of QRS); Long Q wave due to the electrical impulse having to go around the damaged portion of the heart.
What leads of the heart can you see injury and infarction?
Inferior Leads: II, III, aVF
Lateral Leads: I, aVL, V5
Anterior Leads: V1, V2, V3, V4
Why do we normallt read Lead II?
Mean QRS vector points leftward and inferiorly (follows electrical pulse direction)
Normal QRS axis lies between
+90 and 0 degrees
QRS comples is + in leads I and AVF
What would indicate left axis deviation? What causes it?
+ QRS Lead I and - QRS aVF lead
Axis lies between 0 to -90 degrees
Causes:
- Hyperkalemia
- Wolf Parkinson White Syndrome - Right Sided Accessory Pathway (WPW)
What would indicate right sided deviation?
What would cause it?
- QRS lead I and + QRS AVF lead
- Axis lies between +90 to +180
- Causes:
Right Ventricular Hypertrophy
MI
PE
Wolff-Parkinson-White Syndrome - Left Sided Accessory Pathway
Atrial or Ventricular Septal Defect
Normal finding in children
What would indicate extreme right axis deviation?
What causes it?
- QRS lead I and - QRS aVF lead
- Axis lies between +180 to -90 degrees
- Causes
Emphysema
Ventricular Tachycardia
Hyperkalemia
If a right bundle branch is blocked, what happens?
- Right Ventricule depolarization is prolonged (delayed)
- QRS >.12 sec
- RSR V1 (R prime)
- Wide S in V6
If a left bundle branch is blocked, what happens?
- Left ventricle depolarization is delayed
- QRS is wide >0.12 sec
- Broad OR notched R wave V1 and V6
What does Wolff-Parkinson-White Syndrome look like?
- Between the P wave and QRS; Slow up which is called a Delta T wave
- Accessory Pathway meaning alternate; surgeons have to fo in and kill some of the tissue to get scarring over so it doesn’t fire.