ECG Flashcards
Conduction system of heart
SA node> AV node > AV bundle > L and R bundle branches > perkinje fibers > ventricle walls
PR interval
from start to end of P (before Q starts)
ventricular fibrillation
irregular zigzag
- nothing identifiable
T wave
ventricular repolarization
Atrial flutter
atria beats almost 5-6x faster than ventricles
- aka sawtooth appearance
- 250-300bpm
- stop exercise if sxs
- if no sxs, monitor and continue at lower intensity
rate
How fast atria and ventricles are contracting
supraventricular arrhythmias
types
aka atrial arrhythmias
- premature atrial contraction
- atrial tachycardia
- atrial flutter
-atrial fibrillation
- none are emergencies
QT interval
from start of Q to end of T
myocardial ischemia
decreased blood supply
- ST segment DEPRESSED or inverted T wave
-
rhythm
how atria and ventricles are communicating
- P-R interval
- ex AV block
2nd degree heart block, type 2
Mobitz type 2
- no pattern
- normal PR and then QRS randomly dropped
- stop exercise, NOT emergency
- disease of perkinje fibers and bundle of his
QRS complex
ventricular depolarization
(with atrial repolarization within)
2nd degree heart block
Type 1
- partially blocked conduction
- monitor and continue with lower intensity
- Mobitz type 1 aka Weckenbach
- pattern of increased PR until dropped QRS
- disease of AV node
myocardial infarction
- complete occlusion of blood supply and cell death
- ST segment elevation
trigeminy PVC
1 PVC, followed by 2 normal beats
- not an issue
premature atrial contraction
P overlaps with T
- look for little bump in T wave
- not issue
- monitor and continue at lower intensity
1st degree heart block
-delay in conduction
-PR interval >.2 seconds (1 box)
- benign, can be in athletes with increased vagal tone
- each P followed by QRS
- continue exercise
ventricular tachycardia
3 or more PVC in a row
STOP and call 911
- aka v flutter
- can progress to vFib
- can turn upside down and will look the same
multifocal PVC
- > 1 PVC present
- the PVCs dont appear similar in configuration
- STOP exercise and immediately call 911
3rd degree heart block
-fully blocked conduction
- atrium and ventricles doing their own thing - no communication/relationship
- PR constantly changing
- QRS looks wide and bizzare
- EMERGENCY call 911
- need pacemaker
atrioventricular node
-brief delay to allow for ventricular filling
- passes depolarization to ventricles
bigeminy PVC
1 normal beat, then 1 PVC
- not an issue
premature ventricular contraction (PVC)
- heartbeat is initiated by purkinje fibers - skipped beat or palpitations
- ventricles contract before atria
- no P
- wide bizzare QRS
Perkinje fibers
throughout ventricles
- if problem with perkinje fibers - will affect Q
