Rhythms Flashcards
Red flags in ECG
- Lots of jiggly bits
- A lumpy bit on the jiggly bit
- Big tail lumps
- No humps, lumps or jiggles
- Squiggly stuff you have no idea about but the patient looks bad
Critical part of taking ECG
Determining heart rate
Systemic approach to ECGs
- Rate
- Rhythm
- P waves
- PR interval
- QRS complex
- Review rate again
Indicated by heart rate less than 60 bpm
Sinus Bradycardia
Looks like sinus rhythm but faster, 100 bpm or more
Sinus Tachycardia
When the SA node fires slightly irregularly.
- Usually occurs at 60-100bpm
Sinus Arrhythmia
Periodically absent complex, where there is one complex missing exactly
Sinoatrial block
Disorder of impulse formation, results in absent complexes, more than one complex missing
Sinus Arrest
Reflect abnormal electrical impulse formation and conduction
Atrial Dysrhythmias
Why would an atrial dysrhythmia occur?
- Altered automaticity
- Triggered activity
- Reentry
Results from abnormal electrical impulses that sometimes occur during repolarization, when cells are normally quiet
Triggered Activity
Premature beat arising from ectopic pacemaking tissue within atria
Premature Atrial Complexes (PACs)
Two premature beats in a row
Pairs
Three or more premature beats in a row
Runs or Bursts
Every other beat is a premature beat
Bigeminy
Every third beat is a premature beat
Trigeminy
Every fourth beat is a premature beat
Quadrigeminy
Associated with a ventricular rate faster than 100 bpm
Multifocal Atrial Tachycardia (MAT)
Associated with normal ventricular rate (60-100 bpm)
Wandering Atrial Pacemaker (WAP)
When would you see a drop in blood Pressure?
Typically occurs in SVT and is greatest in first 10-30 seconds
Starts or ends suddenly
Paroxysmal
Vagal Manouver
- Have patient bear down as if they are taking a bowel movement, pushing through pelvic floor while tightening ab muscles
- Have patient try to blow the plunger out of a syringe
PCP’S DO NOT PERFORM
Carotid Sinus Massage
Ectopic atrial rhythm in which an irritable site within the atria fires regularly at an extremely rapid rate
Atrial Flutter
Intrinsic Rate for sinus rhythms
60-100 bpm
Intrinsic Rate for Junctional Rhythms
40-60 bpm
What does it mean when P wave is inverted?
Junctional Rhythm
Specialized cells located in the lower portion of the right atrium. Delays the electrical impulse and allows atria to contract and complete filling of ventricles before next ventricular contraction.
AV Node
Connects AV node with bundle branches
Bundle of His
- QRS will usually measure 0.12 sec or less
- Often followed by a noncompensatory (incomplete) pause
- P wave may or may not be present
- If a P wave is present, it is inverted (retrograde) and may precede or follow the QRS
- NOT AN ENTIRE RHYTHM, SINGLE BEAT
Premature Junctional Complex (PJC)
Originates in the AV junction and appears late (after next expected sinus beat)
Junctional Escape Beat
Several sequential escape beats
Junctional Escape Rhythm
- An ectopic rhythm caused by enhanced automaticity of the bundle of His
- Results in a regular ventricular response at a rate of 61 to 100 bpm
Accelerated Junctional Rhythm
Typically characterized by QRS complexes that are abnormally shaped and prolonged (>0.12)
Ventricular Depolarization
T waves are usually in a direction opposite that of the QRS complex
Ventricular Repolarization
- Occurs earlier than the next expected sinus beat
- QRS is typically 0.12sec or greater
- T wave is usually in the opposite direction of the QRS complex
- Full compensatory pause often follows
Premature Ventricular Complex (PVC)
Every other beat is a PVC
Ventricular Bigeminy
Every 3rd beat is a PVC
Ventricular Trigeminy
Every 4th beat is a PVC
Ventricular Quadrigeminy
Premature ventricular beats that look the same in the same lead and originate from the same anatomical site (focus)
Uniform (Unifocal/monomorphic) PVS
- PVCs that appear different from one another in the same lead
- Often (but not always) arise from different anatomical sites
Multiform (Multifocal/polymorphic) PVCs
- Occur when the R wave of a PVC falls on the T wave of the preceding beat
- PVC occurring during this period of the cardiac cycle can cause ventricular tachycardia or ventricular fibrilation
R-on-T PVC
- Three or more ventricular escape beats occurring in a row at a rate of 20-40 bpm
- Agonal rhythm (P waves only, no ventricular activity, rate <20 bpm)
Idioventricular Rhythm (IRV)
Exists when three or more ventricular beats occur in a row at a rate of 41-100 bpm
Accelerated Idioventricular Rhythm (AIVR)
Exists when three or ore PVCs occur in a row at a rate of more than 100 bpm
Ventricular Tachycardia (VT)
A short run lasting less than 30 seconds
Non-sustained VT
Persists for more than 30 seconds
Sustained VT
QRS complexes vary in shape and amplitude from beat to beat and appear to twist from upright to negative or negative to upright and back, resembling a spindle
Polymorphic VT
- Chaotic rhythm that begins in the ventricles
- No organized depolarization of the ventricles
Ventricular Fibrillation (V-Fib)
Total absence of ventricular electrical activity
Asystole
Organized electrical activity is observed in the cardiac monitor but the patient is unresponsive, is not breathing, and has no pulse
Pulseless Electrical Activity (PEA)
A delay or interruption in impulse conduction from the atria to the ventricles occurs as a result of a temporary or permanent anatomic or functional impairment
Atrioventricular Block
Delayed impulse conduction
First-degree AV Block
Intermittent impulse conduction
Second-degree AV block (types I and II)
Absent impulse conduction
Third-degree AV Block
When some, but not all, atrial impulses are blocked from reaching the ventricles. Not every P wave will be followed by QRS.
Second-Degree AV Block
- PR interval prolonged (>0.20 sec) but constant
First Degree Heart Block
A progressive lengthening of the P wave from the corresponding QRS that eventually results in the dropping of a beat
Second-Degree AV Block Type 1 (Wenckebach)
Generally progressive increase increase in the length of the PR intervals until P wave occurs that is not followed by QRS cpmplex
“Classic” Wenckebach Phenomenon
Conduction delay occurs below the AV node, within the His-Purkinje system
Second-Degree AV Block Type II (Mobitz II AV Block)
- P to QRS relation not present before every QRS
- PR interval lgenerally progressively lengthens until P wave is completely blocked at the AV node
- “longer-longer-longer-dropped QRS”
Winckebach AV Block
- More P waves than QRS complexes
- PR interval can be normal or prolonged
- PR intervals before and after a blocked sinus impulse are constant
- QRS complex may be narrow or wide
Second-Degree AV Block Type II
Complete block in conduction of impulses between the atria and the ventricles
Third-Degree AV Block
- P waves upright and rounded more than QRS
- No correlation P to QRS
- AV completely blocks impulses
3rd Degree AV Block
A battery-powered device that delivers an electrical current to the hear to stimulate depolarization
Pacemaker
