P waves: similar; 1:1 with QRS
PR: 0.12-0.20 sec; constant
QRS: equal to or less than 0.1 sec
P waves: similar; 1:1 with QRS
PR: 0.12-0.20 sec; constant
QRS: equal to or less than 0.1 sec
P waves: similar; 1:1 with QRS; at very fast rates, P wave looks like T wave
PR: 0.12-0.20 sec; constant
QRS: equal to or less than 0.1 sec
Rhythm: irregular; often associated with breathing
P waves: similar; 1:1 with QRS
PR: 0.12-0.20 sec; constant
QRS: equal to or less than 0.1 sec
5. Premature Atrial Contraction
Rhythm: regular with premature beats
P waves: premature; 1:1 with QRS
PR: dependent on prematurity of the beat
QRS: usually <0.1 sec, but may be wide
6. Supraventricular Tachycardia
P waves: usually obscure but 1:1 with QRS
PR: 0.12-0.20 sec when present
P waves: P waves appear different; may be difficult to distinguish P waves from T waves
PR: may be shorter or longer than normal; ma be hard to measure
QRS: usually equal to or less than 0.1 sec
Rate: atrial 250-450; ventricular rate variable
Rhythm: atrial regular; ventricular may be regular or irregular
P waves: no P waves. Flutter (sawtooth shaped) waves observed
Rate: atrial 400-600; ventricular variable
Rhythm: ventricular irregular
P waves: no P wave; fibrillatory waves may be present; erratic, wavy baseline
10. Premature Ventricular Contraction
Rhythm: regular with PVCs
P waves: absent; may appear after QRS complex
QRS: >0.12 sec; wide and bizzare
11. Ventricular Tachycardia
Rate: 150-300, typically 200-250
Rhythm: may be regular or irregular
P waves: none (“P-wave” asystole)
13. Ventricular Fibrillation
Rate: cannot be determine - no discernible waves or complexes to measure
Rhythm: rapid and chaotic - no pattern
14. First-Degree AV Block
Rate: usually normal 60-100
P waves: similar, 1:1 with QRS
PR: prolonged (>0.20 sec) but constant
QRS: usually equal to or less than 0.10 sec
15. Second-Degree AV Block, Type I
Rhythm: atrial regular; ventricular irregular
P waves: similar, more P waves than QRS
PR: lengthens with each cycle until a P wave appears without a QRS
QRS: usually equal to or less than 0.10 sec; QRS cycle is periodically dropped
16. Second-Degree AV Block, Type II
Rate: atrial > ventricular
Rhythm: atrial regular; ventricular rhythm irregular
P waves: similar, more P waves than QRS
PR: may be normal or prolonged; remains constant
QRS: usually equal to or greater than 0.10 sec; QRS cycle may be absent after P waves
17. Third-Degree AV Block
Rate: atrial > ventricular; usually slow ventricular rate between 30-60
Rhythm: atrial and ventricular; no relationship between the 2
P waves: similar; more P waves than QRS
PR: non; atria and ventricles beat independently of each other
QRS: may be narrow or wide depending on level of the block