arrhythmia 3 Flashcards
junctional rhythm:
- They may be either slow or fast.
- They are a regular rhythm usually with narrow QRSs.
- P waves are often not seen because they are buried within the QRS complex or they may occur very shortly before or after the QRS.
- P waves are often inverted because they are conducted upward from the AV node rather than downward from the sinus node.
The region surrounding the atrioventricular node is often termed
“the junction” and rhythms originating there are called “junctional rhythms”.
PVC results in
- Wide-abnormal QRS
- No P-Wave
- Ectopic Ventricular Focus - Conducted by Slow Myocardium (not Purkinje)
- Short Path Length Blocks Re-entry
Premature atrial complexes are preceded by
P waves usually of different shape than those of the regular complexes and the QRS is normal
Premature ventricular complexes have
no P waves and the QRS is widened and of abnormal shape
ventricular tachycardia (VT) EKG appearance
- Repetitive Wide-abnormal QRS
- No P-Wave
- Ectopic Ventricular Focus - Conducted by Slow Myocardium (not Purkinje)
- Long Path Length Permits Re- entry
VT heart results
- fibrosis
- infiltrate
- dilation
Rapid ventricular tachycardia or VF require _____.
emergency defibrillation
There is _____ contraction in VT and there is _____ contraction in VF.
typically abnormal ventricular
no
In asystole ECG:
only a straight line is seen on the ECG
prognosis is dismal.
how to identify common cardiac arrythmia steps:
- look for P wave
- does each P wave preced a QRS?
- Is the atrioventricular block present?
- are occasional early QRS complexes present?
- are very fast, abnormal P waves present?
- No P waves but QRS complexes present
- No P wave and no QRS?
Look for the P wave.
A normal P wave is inverted in lead aVR and upright in aVF
Does each P wave precede a QRS?
- Normal sinus rhythm
(rate 60-100 b/min) - Sinus bradycardia
(rate 100 b/min)
Is atrioventricular heart block present?
- 1st degree block
- 2nd degree block
- 3rd degree block
1st degree block
- sinus rhythm
2. with PR interval longer than 0.2 secs
2nd degree block
- sinus rhythm
2. but QRS rate slower than P rate because some P waves do not conduct to the QRS
3rd degree block
- sinus rhythm but
2. QRS slower than P rate because none of the P waves conduct to the QRS.
Are occasional early QRS complexes present?
- Atrial premature beats
2. Ventricular premature beats
Atrial premature beats
QRS is usually narrow and preceded by an abnormal P wave
Ventricular premature beats
QRS is wide without a preceding P wave
Are very fast, abnormal P waves present?
- Atrial flutter
2. Atrial tachycardia
Atrial flutter
- P waves extremely fast 240-320/min
2. typically P:QRS ratio 2:1 or 3:1 or 4:1
Atrial tachycardia
- abnormal P waves
- fast 160-220/min
- abnormal P wave before each QRS
No P waves but QRS complexes present.
- Atrial fibrillation
- Junctional rhythm
- Ventricular tachycardia
Atrial fibrillation
- irregularly irregular QRS beats
- often with an undulating baseline.
- QRS may be narrow or wide
Junctional rhythm
regular rhythm with flat baseline
Ventricular tachycardia
Wide, regular, usually fast QRS
No P wave and no QRS?
- ventricular fibrillation
(wavy baseline) - Asystole
(flat baseline)
second degree AV block
- may reflect conduction system disease, high vagal tone or excessive effects of drugs.
- Some P waves conduct normally to the ventricles but others do not.
- Patterns vary.
second degree AV block can result in
If the rate is too slow to support cardiac output adequately, syncope or confusion may occur requiring a pacemaker.
In Mobitz 1 type
the PR lengthens until a P does not conduct.
In Mobitz 2 type
there is no change in PR as in this example.
