Cardiac Rthyms Review Flashcards
1
Q
NSR - Normal Sinus Rhythm
A
- 60-100bpm
- Regular, with minimal variation between R-R
- P-wave present, upright, and precedes each QRS complex (<100ms wide)
- Constant PR interval
2
Q
Sinus Bradycardia
A
- Same morphology as NSR, only the rate differs
- Rt of less than 60bpm
- Rhythm is regular
3
Q
Sinus Tachycardia
A
- Rt of more than 100bpm
- Rhythm regular
- Increases work of the heart
- Tx typically related to underlying cause of tachycardia
4
Q
Sinus Arrhythmia
A
- Slight variation of sinus rhythm
- Brain-bridge reflex: sudden changes in pressure
- Increases stroke volume and BP
- Normal finding in children/ young adults
5
Q
Sinus Arrest
A
- SA node fails to initiate an impulse
- SA node resumes to normal functioning
- Occasional episodes are not significant
- Tx based on the overall HR and tolerance
6
Q
Sinoatrial Block
A
- results from either pacemaker cells or the transitional cells failing to produce on time
- After a dropped beat, the cycle continues on time
-Characteristics:
Rate - varies
Irregular
P waves present, except when dropped
P:QRS - 1:1
QRS width is normal
7
Q
Wandering Atrial Pacemaker
A
- Pacemaker moves from the SA node to various areas within the atria
- Rhythm is slightly irregular
- Pt’s with significant lung disease
- Tx is usually not indicated
8
Q
PAC - Premature Atrial Complex
A
- Existence of a particular complex within another rhythm, also known as ectopic complexes
- Occurs earlier in tme then next expected complex
- Tx usually not indicated
- Disturbs underlying rhythm and resets the SA node
- frequent PAC’s may cause sensation of heart “ skipping a beat “
- Can be caused by anxiety, or excess caffeine
9
Q
SVT - Supra-ventricular Tachycardia
A
- Pacemaker site is above the ventricles
- HR: must exceed 150bpm
- Tx: medication/ electrical therapy
- Characteristics:
Typically P waves not present (buried due to fast rt)
May sometimes appear inverted or retrograde
Reg Rhythm
Narrow QRS (usually less then 120 ms)
Rt typically 140-280bpm
-PSVT - Paroxysmal SXT: an abrupt onset/ offset can be seen
10
Q
Atrial Flutter
A
- Atria contracting at a rt too rapid for the ventricles to match
- Known as flutter or f waves
- Degenerates into atrial fib
- TX: medication or electrical cardio version
- May be fixed/ variable (conduction ratios)
Characteristics:
Atrial rt and ventricular rt will be different (ventricular fraction of the atrial)
Atrial commonly 250-350bpm
P -waves “ saw tooth “ appearance
QRS width is normal
P:QRS ratio - variable, mostly 2:1, but may be higher
11
Q
A - Fib
A
- Rhythm in which the atria fibrillate or quiver without organized contrxn
- Chaotic flirting of numerous atrial pacemaker cells
- Cells depolarize independently
- Usually a sign of a serious heart problem
- Pre-hospital Tx is usually limited to pts with severe symptoms and prolonged transport time
Characteristics:
No discernible P waves
QRS complexes are innervated haphazardly in an irregularly irregular pattern
Ventricular rt is guided by occasional activation from one of the pacemaker sources
QRS width normal
Rt is variable, ventricular response can be fast/ slow
Fibrilatory rt waves may mimic P-waves - this may lead to misinterpretation
12
Q
Multi focal Atrial Tachycardia
A
- Pacemaker moves within the stria
- Rt of more than 100bpm
- Irregular rhythm
- Pts with significant lung disease
- Tx usually not attempted pre hospital
- Typically transitions between frequent PAC’s and atrial fib/ flutter
Characteristics:
HR: > 100bpm, usually 100-150bpm
Irregularly irregular
At least 3 distinct P wave morphologies
Absence of single dominant atrial pacemaker
Some P waves may be non conducted
13
Q
Junctional (Escape) Rhythm
A
- Allows heart to ‘ escape’ from stopping completely
- Rt: 40–60 bpm
- Tx: pacemaker
- Occurs when rt of the supra-ventricular impulses arriving at the AV node or ventricular is less then the intrinsic rt of the ectopic pacemaker
Characteristics:
Junc rhythm with rt of 40-60bpm
QRS complexes typically narrow (<120ms)
No relationship between QRS and preceding atrial activity
Reg Rhythm
P waves may appear inverted, before, during or after the QRS
14
Q
Accelerated Junctional
A
- Junc rhythm with a rt exceeding 60bpm
- less than 100bpm
- Serious condition
- Occurs when junctional pacemaker that is firing the impulses takes over the normal pacing function of the SA node due to damage with normal conduction
Characteristics:
Rt of 60-100bpm
Regular
P wave may be absent, Nate grade, or retrograde
QRS width is normal
P:QRS = 1:1, if absent, none
15
Q
Junctional Tachycardia
A
- Rt exceeds 100bpm
- If the rt exceeds 150 bpm, cardiac output could suffer, leading to SVT
- Same ethology as Junc rhythm, however the rate is > 100bpm
Characteristics;
P waves retrograde
QRS narrow
PR interval short
Reg. Rhythm ‘
