ch.5 Flashcards
why do arrhythmias happen?
Hypoxia (low O2)
Ischemia (lack of blood flow)
Sympathetic stim
Drugs
Electrolyte disturbances
Bradycardia
Myocardial stretch
WAP
Wandering Atrial Pacemaker
what is a WAP?
- pacemaker activity WANDERS from SA Node to Atrial Automaticity Foci
- VARIATION shape of P wave
- HR within normal range (60-100 BPM)
- P prime or P’
MAT
Multifocal Atrial Tachycardia
what is MAT?
- seen in ppl with COPD
- HR >100
- P’ waves of VARIOUS shapes
- 3 or more atrial foci
- associated with Digitalis Toxicity
Atrial Flutter
- SINGLE strong automaticity foci
- 250-350 cycles per min
- consistent # of P waves before QRS
- 2 P waves to 1 QRS
- R to R evenly spaced out
- HR 60-100 BPM
Atrial Fibrillation
- quivering/shaking
- irregular ventricular rhythm
- MULTIPLE atrial automaticity foci fire
- 0 observable P waves
- no full contraction
- random, no consistent R-R int
T/F: If one lead is atrial flutter, then all leads have atrial flutter?
True. It is the same heart
Escape Rhythm
- automaticity foci escapes overdrive
suppression to pace (any random) - atrial, junctional, ventricular
Escape beat
- happens once
- emit one beat
Sinus Arrest
- SA node stops pace
- Sick Sinus Syndrome (S.S.S.)
- SA node doesn’t consistently work
- Atrial Escape Rhythm
- Atrial foci take over
- 60-80 BPM
- P’ waves not identical to P waves
Atrial Escape Rhythm
- Atrial foci take over
- 60-80 BPM
- P’ waves not identical to P waves
- P’ are identical
- flat line then escape beat/rhythm
T/F: You can tell the difference between a sinus arrest and a sinus block on EKG?
No. looks the same with a long pause/break between
Sinus Block
- Normal sinus rhythm (NSR)
- pause in pacing
- atrial automaticity foci escapes overdrive suppression and takes over pacing
- escape beat
Junctional Escape Rhythm
- between atria and ventricles
- absent pacing from above (Sinus arrest)
- 40-60 bpm (lower HR)
- 0 P wave or inverted P wave
- still a rhythm, R-R consistent
- junctional automaticity foci escapes to pace
T/F: In a junctional escape rhythm, the wave of depolarization is going in the opposite direction?
True
(AV) Junctional Escape Beat
- misses ONE cycle
- transient block at SA node
- may produce retrograde (upside down) atrial depolarization
ventricular escape rhythm
- ventricular automaticity foci not stimulated from above
- purkinje fibers not stim
- 20-40 cycles per min
- doesn’t last long
- total failure of all automaticity foci above
- complete conduction block (atria to ventricles)
T/F: In order to be a rhythm, there has to be back to back consistent rhythms
True
Ventricular escape beat
- severe
- WIDE QRS complex (from ventricles)
- may not have a P wave
- autonomic/ parasympathetic stim
What are the 3 premature beats/contraction?
- Premature atrial (PAC)
- premature junctional (PJC)
- premature ventricular (PVC)
what happens on an EKG when a premature beat occurs?
the R-R interval shortens quickly
what irritates the Atrial and junctional foci?
- adrenaline (normal in stress test)
- low O2 (normal in stress test)
- caffeine, amphetamines, cocaine, beta 1 receptor stims
- hyperthyroidism
- stretch
Premature atrial beat (PAB/C)
- produce P’ waves
- earlier than expected
- P’ wave is unusually shaped
- can be embedded or on top of T wave
- T wave looks larger
Premature Junctional Beat
- 0 P wave
- inverted P wave
- irritable automaticity foci in the AV junction
Premature ventricular contraction (PVC)
- produces premature QRS
- WIDE (>0.12 sec or 3 small boxes)
- enormous amplitude
- usually opposite polarity of normal QRS
- shouldn’t happen @ rest
- low O2 or airway obstructed
PVCs and blood flow
- w/a single PVC the heart will still pump 80% of normal stroke volume (SV)
- w/a second PVC the heart will pump about 58% of normal SV
PVC
- ventricular bigeminy
- ventricular trigemini
- ventricular quadrigeminy
- unifocal
- multifocal
-PVC couplet - run of ventricular tachycardia
Ventricular bigeminy
- one normal beat
- one PVC
- has to happen for @ least 2 cycles (back2back)
Ventricular trigeminy
- 2 normal beats
- one PVC
- @ least 2 cycles for it to occur
Ventricular quadrigeminy
- 3 normal beats
- one PVC
- @ least 2 cycles
PVC Couplet
2 PVCs in a row
- consecutive w/ no normal beat between
Run of ventricular tachycardia (V tach)
- 3 or more PVCs in a row
- longer than 30 sec
Univocal PVC
if PVCs look the same
multifocal PVC
if PVCs look different
Rules of malignancy
- frequent PVCs
- 6 or more per min
- run of consecutive PVCs is V tach
- multiform or multifocal
- PVC on T wave (R on T)
- more severe, deadly arrhythmia
R on T phenomenon
- PVC falls on T wave
- vulnerable period
- dangerous rhythms
- purkinje fibers still in repolarization
MVP
mitral valve prolapse
What is MVP?
- Barlow syndrome
- more common in females
- 6%-17% in female
- 1.5% in male
Tachy-arrhythmias
- Paroxysmal Tachycardia (150-250)
- Flutter (250-350)
- Fibrillation (350-450)
Paroxysmal Tachycardia
-150-250
- sudden fast HR
- from NSR to Parox. V Tach
Supraventricular Tachycardia
- fast HR that happens above ventricles
- QRS normal
- may or may not see P waves
- R-R intervals close together
- sinus tach is form of this
Paroxysmal Supraventricular Tachycardia
- common arrhythmia
- may occur in perfect norm heart
- excitement, coffee, alcohol
- Carotid Massage used to slow HR
Torsades de Pintes
- Twist of points
- very rapid ventricular rhythm
- Low K+
- long QT segment
- Rate 250-350
- brief bursts
- amplitude of QRS changes
Ventricular Flutter
- SINGLE ventricular autom. foci
- Rate 250-350
- smooth sine-wave pattern
- amplitude changes minimally
Ventricular Fibrillation
- ventricles quiver
- follows v flutter
- seen in dying heart
- NO P waves
- NO identifiable QRS waves
- “bag of worms”
Asystole
- flat line
- w/o rhythm
WPW
Wolff-Parkinson-White Syndrome
What is WPW?
- Goes down “Bundle of Kent”
- creates Delta Wave (U shape)
- P wave doesn’t hit baseline
AED
- automated external defibrillator
- small and portable
- place electrodes, machine does work
ICD
- implantable cardioverter defibrillator
- implanted under chest
- detects VF
- delivers defibrillating shock
