IDENTIFY each one of the rhythms using the process of rhythm identification. I a
ID: 3476663 • Letter: I
Question
IDENTIFY each one of the rhythms using the process of rhythm identification. I am looking for what the name of the rhythm is.
NOTES: TO help identify rhythms using the process
Atrial Fibrillation:
Rate: Atrial usually 400-600 bpm, ventricular rate determined by AV blockade
Rhythm: Ventricular rhythm is irregularly irregular
P waves: No identifiable P waves
PR interval: Not measurable
QRS duration: .11 unless intraventricular conduction delay exists
Atrial Flutter:
Ectopic rhythm in which irritable focus fires regularly at a very rapid rate
Rate: Atrial rate 250-350; ventricular rate determined by AV junction
Rhythm: Atrial is regular, ventricular is regular or irregular depending on Av conduction/blockade
P waves: No identifiable P wave, saw-toothed flutter waves
QRS: .11 but may be wide if flutter waves are buried in QRS or intraventricular conduction delay exists
Wolff-Parkinson-White syndrome is common in patients with AVRT
Rate: Usually 60-100 if underlying rhythm is sinus
Rhythm: Regular unless associated with Afib
P waves: Normal unless associated with Afib
PR interval: If P waves are observed, .12
QRS: Wide, usually .12, slurred upstroke of QRS (delta wave) seen in more than one lead
AVNRT:
Rate: 150-250 (usually 180 – 200)
Rhythm: Ventricular rhythm is regular
P waves: Often hidden in QRS, negative P wave can be present, P wave can occur after QRS
PR interval: Not measurable because P waves are not seen before QRS
QRS duration: .11 unless intraventricular conduction delay exists
Atrial Tachycardia:
Rate: 100-250
Rhythm: Regular
P waves: Positive P precedes each QRS, P wave differ in shape from sinus P wave. Rapid rate makes it difficult to distinguish P waves from T waves
PR interval: May be shorter or longer than normal
QRS duration: .10 unless intraventricular conduction delay
Wandering Atrial Pacemaker:
Rate: Usually 60-100 bpm, >100 it is called multifocal atrial tachycardia
Rhythm: May be irregular
P waves: Size, shape, and direction may change from beat to beat. At least 3 different P wave configurations
PR interval: Variable
QRS duration: .11 unless intraventricular conduction delay exists
Premature atrial complex : PAC
Beat is premature (early)
Rhythm is usually regular with premature beats
Rate depends on underlying rhythm
P wave is premature, positive in lead II, one before each QRS unless not conducted, often differs in shape from sinus P wave
PR interval may be normal or prolonged
QRS usually .10 or less but may be wide if aberrantly conducted, may be absent in non-conducted P wave
Explanation / Answer
Answer 8.
Explanation is given below.
Let us consider this to be a 10sec rhythm strip.
There are 18 QRS waves in the given ECG. One large box is 0.2 seconds. In the given figure, QRS interval is five small boxes.
Normal QRS is 0.08 to 0.12 seconds. 5 small boxes is 0.2 seconds. So, QRS interval is normal.
Note that QRS signifies that this case is not AVNRT or atrial tachycardia, wandering atrial pacemaker and premature atrial complex. In all these the QRS is less than 0.12.
Note that QRS signifies that this case can be Wolff-Parkinson-White syndrome.
RR interval is constant; so, rhythm is regular. So, this case is not wandering atrial pacemaker.
Ventricular rate = number of QRS complexes in one minute = 18*6 = 108 bpm
Adult ventricular heart rate is normal if it ranges between 15-40bpm. So, ventricular rate is very high.
Atrial rate= number of P waves in one minute = 18 * 6 = 108 bpm
AV node is usually only capable of generating a rhythm at <= 40-60bpm. So, this rate is also very high.
Also, count the number of beats per minute. For this count the number of boxes between R-R interval. The number of boxes is 2 large boxes.
This will equal to (0.2 *2) = 0.4 seconds
This implies (60/0.4) = 150 beats per minute. Note that normal heart rate is 50 to 100 beats per minute. So, this is very high. This case can be AVNRT and atrial tachycardia.
In atrial flutter and atrial fibrillation, heart rate is 250-350bpm; so this is not atrial flutter or atrial fibrillation.
So, it is proved that the case is Wolff-Parkinson-White syndrome.
***Note: please post the other one separately.