ECGs Flashcards
What are the characteristics of atrial flutter
- Regular atrial rhythm
- Sawtooth pattern
- Atrial rate of 250-300
- Ventricle rate is regular
- QRS is less than 0.12
What are the characteristics of atrial fibrillation
- Irregularly irregular rhythm
- Atrial rate is very fast
- Can see QRS
- No visible P waves (not same morphology)
What are the characteristics of wandering atrial pacemaker
- R-R intervals vary slightly as the pacemaker site changes
- Rhythm can be slightly irregular
- Morphology of P waves changes
What are the characteristics of Premature atrial contractions
- Premature ectopic beat will interrupt the regularity of the rhythm
- P wave of premature beat will have a different morphology
What are the characteristics of premature junctional contraction (PJC)
- Premature ectopic beat will interrupt the regularity of the rhythm
- P wave can come before, after or be lost in the QRS (if visible the P wave will be inverted)
What are the characteristics of junctional escape rhythm
- R-R intervals are constant
- Regular rhythm
- P waves are inverted and come either before or after the QRS or are lost entirely.
What are the characteristics of SVT
- Rate: 150-200 bpm
- Regular rhythm
- P waves are not present (hidden in the T waves of proceeding beat)
What are the characteristics of 1st degree AV block
- Long P-R intervals (greater than 0.20 seconds)
- Regular rhythm
What are the characteristics of 2nd degree heart block type 2
- P waves are consistent, but the QRS are not
- Always more P waves than QRS complexes
What are the characteristics of 3rd degree heart block
- P waves and QRS march to their own beat but they are both regular but not synced with each other.
What are the characteristics of PVC
- Regular or irregular rhythm
- Wide QRS complex beat that premature and no proceeding P wave
What are the characteristics of ventricular tachycardia
- Rhythm: regular (can be slightly irregular)
- Atrial rate cannot be determined
- Ventricular rate is 150-200 bpm
- P waves are not present
- QRS are wide and bizarre
- Another type is torsade de Pointes
What are the characteristics of ventricular fibrillation (VF)
- No waves or complexes can be analyzed to determines regularity (chaotic)
What are the characteristics of idioventricular rhythm
- Slow ventricular escape rhythm with wide QRS (wide and slow and the P waves don’t show)
- Ventricular rate 20-40 bpm
- Regular rhythm
- No P waves
- QRS is wide and bizarre
- Accelerated = 40-100 bpm
What is the P wave
Atrial depolarization
<0.12 seconds (3 boxes)
What is the P-R interval
Impulse delay at the AV node
0.12-0.20 seconds (3-5 boxes)
What is the QRS complex
Ventricular depolarization
0.08-0.12 seconds (2-3 boxes)
What is the T wave
Ventricular repolarization
What is the ST-segment
Distance from the end of the S wave to the beginning of the T wave
Depression = Ischemia
Elevation = Infarct
What is the QT-interval
- Time interval between the onset of the depolarization and the termination of repolarization of the ventricles
- Dependent on the heart rate (should be less than half of the R-R interval)
What is the R-R interval
The time between two successive ventricular depolarizations
What are the characteristics of Wolf-Parkinson-White syndrome
- Short P-R interval (less than 0.12 seconds)
- Delta wave present
What are the characteristics of 2nd degree heart block type 1 (Wenckebach)
- P-R intervals get progressively longer until one P wave is not followed by a QRS
- Wider, wider, wider, gone
