Ekg Flashcards
How long should the QRS complex be?
40-100msec
What does the PR interval represent?
Delay in conduction from the AV node
How long does the PR interval should be?
120-200msec
What does the QT interval represent?
Duration of action potential
What does the ST segment represent?
Phase 2 plateu phase of action potential
QT interval is inversely proportional to what…?
Heart rate
- Taqui: short QT interval
- Bradi: long QT interval
Intervals to calculate heart beat:
- 300
- 150
- 100
- 75
- 60
- 50
What are the steps to read EKG?
- Rate & Rhythm.
- Waves. (Normal)
- PR interval (consistent)
- Electrical Axis (mean)
What is the Mean Electrical Axis of the Heart?
Between -30 and +110
Causes of Left Axis Deviation:
- Enlarged Left Heart
- Acute Right MI, unless right ventricle is dilated.
- Conduction defects left ventricle (except posterior B.B.)
Causes of right Axis deviation:
- Enlarged right Heart.
- Left sided acute MI; unless left ventricle dilates.
- Right sided conduction defects or posterior left BB
Primary characteristic of First Grade Block:
- Prolonged PR intervals (>200msec) (>0.2seg)
2. Regular rhythm
What are second degree blocks divided into?
- Mobitz type 1 (Wenckebach).
2. Mobitz Type 2
Primary characteristics of second degree block Mobitz type I (Wenckebach)?
- Regularly irregular
- Progressive PR prolongation
- Blocks!!! (One drop!)
Primary characteristics of second degree block Mobitz type II??
- Consistent PR interval
- Block!
- Can progress to 3rd degree
Primary characteristics of Third Degree Block?
- Complete block.
- P and QRS waves are not associated.
- A rate >V rate
- No consistent PR interval
Infectious disease associated with Third Degree Block?
Lyme’s disease
Primary characteristics of atrial flutter?
- P waves are sawtooth appearance.
- Regular RR’s.
- Super fast HR (>280 x min)
Primary characteristics of Atrial Fibrillation?
- Irregularly irregular.
- Irregular RR
- No discernible P waves
Wolf-Parkinson-White is the result of what accessory pathway?
Bundle of Kent
Primary EKG characteristics of WPW syndrome ?
- Short PR interval
2. Slurred R (delta wave) 🎢
Causes of ST elevation:
- Transmural infarct (subepicardic isquemia)
- Prinzmetal angina.
- Pericarditis
Causes of ST depression:
- Subendocardial isquemia
2. Stable angina
Hyperkalemia EKG changes??
- Sharp-spiked T waves
2. Short QT interval
Hypokalemia changes in EKG?
- U waves.
2. Prolonged QT interval
EKG changes in hypercalcemia?
- Decreases QT interval
EKG changes in hypocalcemia ?
- Increased QT interval