Rate:
The atrial and ventricular rates are equal; the heart rate is usually
60 - 100 beats per minute Rhythm:
The R - R intervals are constant; the rhythm is regular P
Wave: The P waves are uniform. There is one P wave in
front of every QRS complex. PRI:
0.12 - 0.20 seconds and constant. QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T
Waves:
usually slighly rounded and asymmetrical; T wave is less than half the height
of the QRS
Sinus Bradycardia
Rate:
The atrial and ventricular rates are equal; the heart rate is less than
60 beats per minute Rhythm:
The R - R intervals are constant; the rhythm is regular P
Wave: The P waves are uniform. There is one P wave in
front of every QRS complex. PRI:
0.12 - 0.20 seconds and constant. QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T Waves:
usually slighly rounded and asymmetrical; T wave is less than half the height
of the QRS
Sinus
Tach
Rate:
The atrial and ventricular rates are equal; the heart rate is usually
between 100 to 160 beats per minute Rhythm:
The R - R intervals are constant; the rhythm is regular P
Wave: The P waves are uniform. There is one P wave
in front of every QRS complex. PRI:
0.12 - 0.20 seconds and constant. QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T
Waves: usually slighly rounded and asymmetrical; T wave is
less than half the height of the QRS
Sinus
Arrythmia
Rate:
The atrial and ventricular rates are equal; the heart rate is usually
6o to 100 beats per minute; can be slower. Rhythm:
The R - R intervals vary; the rhythm is slightly irregular P
Wave: The P waves are uniform. There is one P wave
in front of every QRS complex. PRI:
0.12 - 0.20 seconds and constant. QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T
Waves: usually slighly rounded and asymmetrical; T wave is
less than half the height of the QRS
Wandering
Atrial Pacemaker
Rate:
The atrial and ventricular rates are equal; the heart rate is usually
6o to 100 beats per minute; can be slower. Rhythm:
The R - R intervals vary as the pacemaker site changes; the rhythm
can be slightly irregular P
Wave: The morphology of the P waves changes as the
pacemaker site changes. There is one P wave in front of every QRS complex.
Some P waves may be difficult to see, depending on the pacemaker site. PRI:
The PRI measurement will vary slightly as the pacemaker site changed. PRI measurements
should be 0.12 - 0.20 seconds. Some PRI measurements may be less than 0.12. QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T
Waves: usually slighly rounded and asymmetrical; T wave is
less than half the height of the QRS
Premature Atrial Contraction
Rate: The
overall rate will depend on the underlying rhythm Rhythm: As
this is a single premature ectopic beat, it will affect the regularity
of the underlying rhythm P
Wave: The P wave of the premature beat will differ
from the morphology of of the P waves of the undelying rhythm. The
ectopic beat will have a P wave, but it can be unusual - can be notched
or flattened. It can be buried in the preceding T wave. PRI:
The PRI should be 0.12 - 0.20 seconds, but can be prolonged. The PRI of the ectopic
beat will more than likely be different from the PRI of the underlying rhythm.
QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T Waves:
usually slighly rounded and asymmetrical; T wave is less than half the height
of the QRS
Atrial Tachycardia
Rate:
The atrial and ventricular rates are equal; the heart rate is usually
150-250 beats per minute Rhythm:
The R - R intervals are constant; the rhythm is regular P
Wave: There is one P wave in front of every QRS complex.
The morphology of the P wave will have a different morphology than
the P waves of a sinus rhythm.
Because of the rapid rate, the P waves can be hidden in the preceding T
wave. PRI:
0.12 - 0.20 seconds and constant. The PRI may be difficult to measure if the
P wave is obscured by the preceding T waves. QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T Waves:
usually slighly rounded and asymmetrical; T wave is less than half the height
of the QRS
Atrial Flutter
Rate:
The atrial rate is between 250-350 beats per minute. Ventricular rate
will depend on the ratio of impulses conducted to the ventricles Rhythm:
The atrial rhythm is regular. The ventricular rhythm will be regular
if the AV node conducts impulses through in a consistent pattern. If
the pattern varies, the ventricular rate will be irregular. P
Wave: When the atria flutter, they produce a series of
well-defined P waves. When seen together, they resemble a "sawtooth" pattern. PRI:
Because of the flutter waves' proximity to the QRS complex, it is difficult,
if not impossible to determine the PRI QRS:
less than 0.12 seconds - can be difficult to measure if any flutter waves
are concealed in the QRS complex S-T Segment: neither
elevated or depressed T Waves:
Difficult to see with flutter waves
Atrial Fibrillation
Rate:
The atrial rate can't be measured because it is so chaotic. It probably
exceeds 350 beat per minute. The ventricular rate is much slower because
AV node blocks most of the impulses. If the ventricular rate is below
100, the rhythm is said to be "controlled." If the rate is
over 100, it is called atrial fibrillation with a rapid ventricular response Rhythm:
The atrial rhythm is not measurable. All atrial activity is chaotic.
The ventricular rhythm is irregular. P
Wave: The atria aren't depolarizing in an effective
method, they are fibrillating. So no P wave is produced. PRI:
Since there are no P waves visible, the PRI can't be measured QRS:
less than 0.12 seconds - can be difficult to measure if any flutter waves are
concealed in the QRS complex S-T Segment: neither
elevated or depressed T Waves:
usually slightly rounded and asymmetrical; T wave is less than half the height
of the QRS
Premature Junctional Contraction
Rate:
The rate will depend on the underlying rhythm Rhythm:
Slightly irregular - the premature ectopic beat will interrupt the regularity
of the underlying rhythm, so the R-R interval will be irregular P
Wave: The P wave can come before or after the QRS complex,
or it can be lost in the QRS complex. If visible, the P wave will be inverted. PRI:
If the P wave precedes the QRS complex, the PRI will be less than 0.12 seconds.
If the P wave falls within the QRS complex or following it, the will be no PRI QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T Waves:
usually slightly rounded and asymmetrical; T wave is less than half the height
of the QRS
Junctional Escape Rhythm
Rate:
The atrial and ventricular rates are equal; the inherent heart rate of
the AV Junction is 40 - 60 beats per minute Rhythm:
The R - R intervals are constant; the rhythm is regular P
Wave: The P wave can come before or after the QRS complex,
or it can be lost in the QRS complex. If visible, the P wave will be inverted. PRI:
If the P wave precedes the QRS complex, the PRI will be less than 0.12 seconds.
If the P wave falls within the QRS complex or following it, the will be no PRI QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T Waves:
usually slightly rounded and asymmetrical; T wave is less than half the height
of the QRS
Accelerated Junctional Rhythm
Rate:
The atrial and ventricular rates are equal. The rate will be faster
than the AV junctions intrinsic rate but not yet a true tachycardia.
Typically, the rate is between 60 - 100. Rhythm:
The R - R intervals are constant; the rhythm is regular P
Wave: The P wave can come before or after the QRS complex,
or it can be lost in the QRS complex. If visible, the P wave will be inverted. PRI:
If the P wave precedes the QRS complex, the PRI will be less than 0.12 seconds.
If the P wave falls within the QRS complex or following it, the will be no
PRI QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T
Waves:
usually slightly rounded and asymmetrical; T wave is less than half the height
of the QRS
Junctional Tachycardia
Rate:
The atrial and ventricular rates are equal. Typically, the rate is between
100 - 180. Rhythm:
The R - R intervals are constant; the rhythm is regular P
Wave: The P wave can come before or after the QRS complex,
or it can be lost in the QRS complex. If visible, the P wave will be
inverted. PRI:
If the P wave precedes the QRS complex, the PRI will be less than 0.12 seconds.
If the P wave falls within the QRS complex or following it, the will be no PRI QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T
Waves: usually slightly rounded and asymmetrical; T wave is
less than half the height of the QRS
First Degree Heart Block
Rate:
Depends on underlying rhythm Rhythm:
Depends on underlying rhythm P
Wave: Upright and uniform. Each P wave followed by a
QRS complex PRI: > 0.20
seconds across entire strip QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T Waves:
usually slightly rounded and asymmetrical; T wave is less than half the height
of the QRS
A first degree block is not a rhythm in itself. It is a prolonged PRI that can
be encountered in an otherwise normal rhythm or in practically any other cardiac
rhythm.
Type
II Second Degree Heart Block
Rate:
Atrial rate is typically normal. Because many of the atrial impulses
are blocked, the ventricular rate will be in the bradycardia range, usually
with a 2 - 1, 3 - 1, or a 4 - 1 conduction rate. Rhythm:
If the conduction rate is consistent, the R - R interval will be constant,
and the rhythm will be regular. If the conduction ratio varies, the R
- R will be irregular. P
Wave: Upright and uniform. There are more P waves than
QRS complexes PRI:
Will
be constant on conducted beats. Could be prolonged in comparison to a normal
PRI. QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T Waves:
usually slightly rounded and asymmetrical; T wave is less than half the height
of the QRS
Type I Second
Degree Block (Wenckebach)
Rate:
Because some beats aren't conducted, the ventricular rate is usually
slightly
slower than normal. The atrial rate is normal Rhythm:
The R - R interval is irregular P
Wave: Upright and uniform. There are more P waves than
QRS complexes PRI:
Interval get progressively longer, until one P wave isn't followed by a QRS complex.
There is a pattern to this cycle as it is repeated. QRS:
less than 0.12 seconds S-T Segment: neither
elevated or depressed T Waves:
usually slightly rounded and asymmetrical; T wave is less than half the height
of the QRS
3rd
Degree Heart Block (Complete Heart Block)
Rate:
The atrial rate is typically normal. The ventricular rate will be slower.
If a junctional focus is controlling the ventricles, the rate will be
40 - 60. If the focus is ventricular, the rate will be 20 - 40. Rhythm:
Since the atrial and ventricular foci are firing regularly, the P - P
and the R - R intervals will be regular. P
Wave: Upright and uniform. There are more P waves than
QRS complexes PRI:
There is no PRI, because the block at the AV node is complete. There is no association
between the P waves and the QRS complexes. QRS:
If the focus is junctional, less than 0.12 seconds. If the focus is ventricular,
the QRS will be > 0.12. S-T Segment: neither
elevated or depressed T Waves:
usually slightly rounded and asymmetrical; T wave is less than half the height
of the QRS
Premature
Ventricular Contractions
Rate:
The rate is determined by the underlying rhythm. A PVC can interrupt
the regularity of the underlying rhythm (assuming the underlying rhythm
IS
regular), unless the PVC interpolated (falls between two sinus beats) Rhythm:
The rate depends on the underlying rhythm. *Note* PVCs are not usually
included in the rate determination because the frequently don't produce
a pulse. P
Wave: As the name implies, this is a ventricular contraction.
Therefore there will not be a P wave preceding the PVC. PRI:
There is no PRI, as the focus is ventricular. QRS:
The QRS is wide and bizarre, usually 0.12 or greater. It will look different
from the underlying QRS complexes. S-T Segment: neither
elevated or depressed T Waves:
The T wave is frequently deflected in the opposite direction of the QRS complex.
PVCs can fall into patterns with the underlying rhythm - if the PVCs alternate
with the normal QRSs, it is called bigeminy. If every third beat is a PVC, trigeminy.
Every fourth beat is quadrigeminy.
PVCs can be unifocal (have a single ectopic
focus), or multifocal (multiple ectopic foci).
If there are several PVCs in a row, without an intervening, normal QRS, it is
called a "run" of PVCs. If there are only two PVCs one right after the other,
it is called "couplets."
A PVC falling on the downslope of a T wave is called "R on T," and
can easily lead
to
V fib.
Ventricular
Tachycardia
Rate:
The atrial rate can't be determined. The ventricular rate is 150 - 250.
If the rate is below 150, it is called a slow V tach. Rhythm:
The rhythm is usually regular. P
Wave: Not usually visible. PRI:
There is no PRI, as the focus is ventricular. QRS:
The QRS is wide and bizarre, usually 0.12 or greater. It is sometimes difficult
to differentiate between QRS complexes and T waves. S-T Segment: Difficult,
if not impossible to see. T Waves:
Difficult to differentiate T waves from QRS complexes
Ventricular
Fibrillation
Rate: Ø Rhythm:
None. The baseline is totally chaotic P
Wave: None are visible. PRI:
There is no PRI. QRS:
None S-T Segment: None T Waves:
None
Ideoventricular
Rate:
20 - 40 per minute, can drop below 20 as the heart dies Rhythm:
Regular P
Wave: There are none. PRI:
There is no PRI. QRS:
Wide and bizarre, > 0.12 or greater S-T Segment: Generally
deviates from the baseline T Waves:
Frequently deflecting opposite the QRS complex
Asystole
Rate: Ø Rhythm:
None. P
Wave: None PRI:
There is no PRI. QRS:
None S-T Segment: None T Waves:
None